Engineering & Piping design

Manual No. E5000
October 1, 2007

Engineering & Piping Design Guide
Fiber Glass Systems Fiberglass Reinforced Piping Systems

I N T R O D U C TION

INTRODUCTION PIPING SYSTEMS
Fiber Glass Systems’(FGS) fiberglass reinforced epoxy and Epoxy Resin Systems:
vinyl ester resin piping systems possess excellent corrosion · Z-CORE® (High Performance Resin)
resistance and a combination of mechanical and physical · CENTRICAST PLUS® RB-2530
properties that offer many advantages over traditional piping · CENTRICAST® RB-1520
systems. Fiber Glass Systems is recognized worldwide as a · GREEN THREAD®
leading supplier of piping systems for a wide range of chemi- · GREEN THREAD Performance Plus
cal and industrial applications. · MARINE-OFFSHORE
· GREEN THREAD 175
This manual is provided as a reference resource for some
· GREEN THREAD 175 Conductive
of the specific properties of FGS piping systems. It is not in-
· GREEN THREAD 250
tended to be a substitute for sound engineering practices as
· GREEN THREAD 250 Cconductive
normally employed by professional design engineers.
· GREEN THREAD 250 Fire Resistant
Fiber Glass Systems has an international network of dis- · RED THREAD® II
tributors and trained field personnel to advise on proper in- · RED THREAD II Performance Plus
stallation techniques. It is recommended they be consulted · RED THREAD II JP
for assistance when installing FGS piping systems. This not · SILVER STREAK® (FGD Piping)
only enhances the integrity of the piping system, but also in- · CERAM CORE® (Ceramic-lined Piping)
creases the efficiency and economy of the installation. · F-CHEM® (Custom Piping)
Additional information regarding installation techniques is · HIGH PRESSURE Line Pipe and
provided in the following FGS installation manuals: Downhole Tubing*

Manual No. F6000 Pipe Installation Handbook Vinyl Ester Systems:
for Tapered Bell & Spigot Joints · CENTRICAST PLUS CL-2030
Manual No. F6080 Pipe Installation Handbook · CENTRICAST CL-1520
for Straight Socket Joints and · F-CHEM (Custom Piping)
Butt & Wrap Joints
Manual No. F6300 Pipe Installation Handbook
for Marine-Offshore Piping * Available from FIBER GLASS SYSTEMS,
National Oilwell Varco Company, San Antonio, Texas
Phone: (210) 434-5043 · FAX: (210) 434-7543
Website: http://www.starfiberglass.com
General Policy Statement

It is the policy of Fiber Glass Systems to improve its products
continually. In accordance with that policy, the right is re-
served to make changes in specifications, descriptions, and
illustrative material contained in this manual as conditions
warrant. Always cross-reference the bulletin date with the
most current version listed at www.smithfibercast.com. The
information contained herein is general in nature and is not
intended to express any warranty of any type whatsoever nor
shall any be implied. In providing this technical information,
Fiber Glass Systems has not been retained as and does not
assume the role of engineering consultant to any user or cus-
tomer. Fiber Glass Systems does not accept and specifically
disclaims any responsibility or warranty for the design, speci-
fication, installation, or design performance of any fiberglass
piping system.

SAFETY
Fiber Glass Systems has developed a computer program
This safety alert symbol indicates an important
specifically for our fiberglass products. This software
safety message. When you see this symbol, be
program called Success By Design is available on our
alert to the possibility of personal injury.
website at http://www.smithfibercast.com.

© 2005, National Oilwell Varco
® Trademarks of Varco I/P, Inc.

ii Engineering & Piping Design Guide

TABLE OF CON T EN T S

Introduction........................................................................ i
. SECTION 5 — Other Considerations....................... 21
Piping System Selection.................................................1
. A. Abrasive Fluids............................................................ 21
B. Low Temperature Applications....................................21
SECTION 1 — Flow Properties...................................2 C. Pipe Passing Through Walls or
Preliminary Pipe Sizing.......................................................2 Concrete Structures. ................................................... 21
.
Detailed Pipe Sizing D. Pipe Bending............................................................... 21
A. Liquid Flow. .............................................................2
. E. Static Electricity........................................................... 22
B. Loss in Pipe Fittings. ...............................................4
. F. Steam Cleaning........................................................... 22
C. Open Channel Flow.................................................5 G. Thrust Blocks............................................................... 22
D. Gas Flow..................................................................5 H. Vacuum Service.......................................................... 22
.
I. Valves .........................................................................22
SECTION 2 — Above Ground System Design Using J. Vibration...................................................................... 23
.
Supports, Anchors & Guides. .....................................7
. K. Fluid (Water) Hammer.................................................23
Piping Support Design L. Ultraviolet (U.V.) Radiation and Weathering. .............. 23 .
A. Support Bracket Design...........................................7 M. Fungal, Bacterial, and Rodent Resistance.................. 23
B. Typical Guide Design. .............................................8
.
C. Anchor Design.........................................................9 SECTION 6 — Specifications
D. Piping Support Span Design. ................................11
. and Approvals............................................................... 24
A. Compliance with National Specifications..................... 24
SECTION 3 — Temperature Effects......................... 12
. B. Approvals, Listings, and Compliance
System Design..................................................................12 with Regulations.......................................................... 24
Thermal Properties and Characteristics............................12
Fundamental Thermal Analysis Formulas A P P E N D IC E S
A. Thermal Expansion and Contraction..................... 13
. Appendix A Useful Formulas..........................................27
B. Anchor Restraint Load...........................................13 Appendix B Conversions................................................30
C. Guide Spacing.......................................................13
Flexibility Analysis and Design
A. Directional Change Design....................................13 LIS T OF TA B LE S
B. Expansion Loop Design.........................................14 Table 1.0 Typical Applications...........................................1
C. Expansion Joint Design.........................................14 Table 1.1 Flow Resistance K Values for Fittings. .............. 4
.
D. Heat Tracing..........................................................15 Table 1.2 Typical Liquid Properties....................................4
E. Thermal Conductivity.............................................16 Table 1.3 Typical Gas Properties.......................................6
F. Thermal Expansion in Buried Pipe........................ 16
. Table 2.0 Minimum Support Width.....................................7
G. Pipe Torque due to Thermal Expansion................ 16 Table 2.1 Saddle Length....................................................8
Table 4.0 Recommended Bedding and Backfill............... 18
SECTION 4 — Pipe Burial...........................................17 Table 4.1 Nominal Trench Widths....................................18
Pipe Flexibility...................................................................17 Table 6.0 ASTM 2310 Classification................................24
Burial Analysis Table 6.1 Classifying Fiberglass Flanges
A. Soil Types..............................................................17 to ASTM D4024. ..............................................25
.
B. Soil Modulus .........................................................18 Table 6.2 Classifying Fiberglass Pipe
Trench Excavation and Preparation Using ASTM D2310 and
A. Trench Size. ..........................................................18
. Specifying Pipe Using ASTM D2996
B. Trench Construction..............................................18
. and D2997. ...................................................... 26
.
C. Maximum Burial Depth..........................................19
.
D. Roadway Crossing. ..............................................19
.
Bedding and Backfill
A. Trench Bottom.......................................................20
B. Backfill Materials....................................................20
C. Backfill Cover.........................................................20
D. High Water Table...................................................20

Engineering & Piping Design Guide iii

P R O D U C T SE L E C T ION a n d A PPLICATION

PRODUCT SYSTEM SELECTION TYPICAL APPLICATIONS
When selecting a piping system for a particular application, Fiberglass piping is used in most industries requiring corro-
it is important to consider the corrosive characteristics of the sion resistant pipe. FRP piping is used in vent and liquid ap-
media to which the pipe and fittings will be exposed, the nor- plications that operate from -70°F to 300°F (-57°C to 149°C).
mal and potential upset temperatures and pressures of the Fiber Glass Systems piping systems use high grade resins
system, as well as other environmental factors associated that are resistant to acids, caustics or solvents. Abrasion re-
with the project. Fiberglass reinforced plastic (FRP) piping sistant materials can be used in the piping inner surface liner
systems provide excellent corrosion resistance, combined to enhance wear resistance to slurries. Table 1.0 is a brief
with high temperature and pressure capabilities, all at a rela- list of the many applications and industries where fiberglass
tively low installed cost. Fiber Glass Systems engineers, us- piping has been used successfully. See FGS Bulletin No.
ing epoxy, vinyl ester, and polyester resins, have developed E5615 for a complete chemical resistance guide.
a comprehensive array of piping systems designed to meet Fiber Glass Systems piping systems can be installed in ac-
the most demanding application requirements. Piping sys- cordance with the ASME B 31.3 piping code. Second party
tems are available with liners of varying type and thickness, listings from regulatory authorities such as Factory Mutual,
with molded, fabricated, or filament wound fittings, ranging in NSF, UL/ULC, and marine registrars are in place on several
size from 1" to 72"(25 to 1800 mm) in diameter. of these piping systems.

TABLE 1.0 Typical Fiberglass Pipe Applications by Industry
INDUSTRY
Applications Chemical Petro Marine Pharma- Food Power Pulp and Waste Water Mining and
Process Chemical Offshore ceutical Processing Plants Paper Treatment Metal Refining

Aeration X
Brine Slurry X
Bottom Ash X
Chemical Feed X X X X X X X
Column Piping X
Condensate Return X X X X X X X
Conduit X X X X
Cooling Water X X X X X
Disposal Wells X X X X X
DownholeTubing
& Casing X X X
Effluent Drains X X X X X X X X X
Fire Mains X X X X X
Flue Gas
Desulfurization X
Guttering &
Downspouts X X X X
Oily Water X X X
Scrubber Headers X X X
Seawater X X X
Slurry X X
Vents X X X X X X X X
Water X X X X X X X X
Waste Treatment X X X X X X X X
Buried Gasoline X

1 Engineering & Piping Design Guide

SECTION 1. FLOW PROPE R T IES

SECTION 1. Flow Properties
The smooth interior surface of fiberglass pipe, combined with Detailed Pipe Sizing
inside diameters larger than steel or thermoplastic pipe of the A. Liquid Flow
same nominal diameter, yield significant flow advantages.
This section provides design techniques for exploiting the Fluid flow characteristics are very sensitive to the absolute
flow capacity of fiberglass pipe. roughness of the pipe inner surface. The absolute rough-
ness of Smith Fibercast piping is (0.00021 inches) 1.7 x
10 -5 feet (1). This is less than 1/8 the average value for
Preliminary Pipe Sizing (non-corroded) new steel of (0.0018 inch) 15 x 10-5 feet(2).
The determination of the pipe size required to transport a given For ambient temperature water, the equivalent Manning
amount of fluid is the first step in designing a piping system. value (n) is 0.009 and the Hazen-Williams coefficient is
150.
Minimum recommended pipe diameters.
The most commonly used pipe head loss formula is the
Clear Liquids Darcy-Weisbach equation.

Eq. 1 Eq. 5

Where:
Corrosive or erosive fluids
Hf = Pipe friction loss, ft(m)
f = Friction factor
L = Length of pipe run, ft (m)
Eq. 2
D = Inner diameter, ft (m)
V = Fluid velocity, ft/sec (m/sec)
g = Acceleration of gravity, 32.2 ft/s2 (9.81 m/s2)
Where:
d = Pipe inner diameter, inch
The friction factor is dependent on the flow conditions, pipe
Q = Flow rate, gal/min (gpm) diameter and pipe smoothness. The flow conditions are
Sg = luid specific gravity, dimensionless
F determined by the value of the Reynolds Number. There
p = Fluid density, lb/ft3 are four flow zones defined by the Reynolds Number; they
are laminar, critical, transitional and turbulent.
Recommended maximum fluid velocities For laminar flow (Reynolds Number below 2,000), the
Clear fluids friction factor is calculated by Eq. 6

Eq. 3 Eq. 6

Where Nr is the dimensionless Reynolds Number
Corrosive or erosive fluids
Eq. 7
Eq. 4
Where:
D = Pipe inner diameter, ft (m)
Where: V = Fluid velocity, ft/sec (m/sec)
V = velocity, ft/sec v = Fluid kinematic viscosity, ft2/sec (m2/sec)
p = fluid density, lb/ft3 Nr = Reynolds Number
f = Friction Factor
Typical fiberglass piping systems are operated at flow veloci-
ties between 3 & 12 ft/sec.
1 Based on testing at Oklahoma State University in Stillwater, OK.
2 Cameron Hydraulic Data, Ingersoll-Rand, Seventeenth Edition, 1988.

Engineering & Piping Design Guide 2

SE C T I O N 1 . F L OW P R OP E R T IES

For turbulent flow (Reynolds Number greater than 4,000 is considered the critical zone. Flow is neither fully
4,000), the friction factor is calculated by the Colebrook laminar or turbulent, although it is often assumed to be
Equation. laminar for calculation purposes. Flow with Reynolds
numbers between 4,000 and 10,000 is called the transi-
tional zone where use of the Colebrook equation is con-
Eq. 8 sidered more appropriate.

These equations are quickly solved using a computer pro-
Where: gram, Success By Design, developed by Smith Fibercast
D = Pipe inner diameter, inch (mm) specifically for our fiberglass products.

e = Absolute roughness, inch (mm)
Nr = Reynolds Number, unit less A demonstration of the Darcy-Weisbach and Colebrook
equations for fiberglass pipe is shown in Figure 1.0.
f = Friction Factor, unit less
The flow with Reynolds numbers between 2,000 and

Fiberglass Pipe Pressure Loss Curves for Water
Figure 1.0
Basis: Specific Gravity of 1.0 and Viscosity of 1.0 cps

25
20
15
Ve 10
loc
Pressure Loss - psig per 100 Feet of Pipe

(Ft it
/Se y
10 c) 7
5
4
3

"
2

54
60"
"
72
1
1"

0.1
"
1.5

2"

3"

me 4"
ter
6"

8"
Dia

0.01
10"
"
16 14"
12
)
er
ch

" "
20 18
"
nn
(in

"
24
eI

30"
Pip

"
36
"
42
"
48

0.001
1 10 100 1,000 10,000 100,000
Flow Rate (gpm) - Gallons per Minute


B. Loss in Pipe Fittings Typical values of k are given in Table 1.1.
The head loss through a fitting is proportional to the fluid The most common method for determining the contribu-
velocity squared (V2). Equation 9 relates the head loss tion to the overall piping system of the fittings head loss
in fittings to the fluid velocity by incorporating a fitting loss is to convert the fitting head loss into an equivalent pipe
factor obtained from experimental test data. length. As an example, use 60°F water as the working
fluid in a 3-inch diameter piping system with an internal
flow of 10 ft/sec. The equivalent pipe length for a short
Eq. 9
radius 90° elbow would be 6.9 feet for RED THREAD II
and 5.9 feet for Centricast Plus CL-2030 . The two
Where: piping systems have different inner diameters that con-
tribute to the differences in equivalent footage. Therefore
hf = itting friction loss, ft (m)
F
for best accuracy it is recommended that FGS computer
k = Flow resistance coefficient software Success By Design be used to determine fittings
V = fluid velocity, ft/sec equivalent piping footage.
g = acceleration of gravity, 32.2 ft/s2 Typical liquid properties are presented in Table 1.2.

TABLE 1.1 Flow Resistance k Values for Fittings
Fitting/Size (In.) 1 1 1/2 2 3 4 6 8-10 12-16 18-24

Short Radius 90º Elbow 0.75 0.66 0.57 0.54 0.51 0.45 0.42 0.39 0.36

Sweep Radius 90º Elbow 0.37 0.34 0.30 0.29 0.27 0.24 0.22 0.21 0.19

Short Radius 45º Elbow 0.37 0.34 0.30 0.29 0.27 0.24 0.22 0.21 0.19

Sweep Radius 45º Elbow 0.20 0.18 0.16 0.15 0.14 0.13 0.12 0.11 0.10

Tee Side Run 1.38 1.26 1.14 1.08 1.02 0.90 0.84 0.78 0.72

Tee Thru Branch 0.46 0.42 0.38 0.36 0.34 0.30 0.28 0.26 0.24

TABLE 1.2 Typical Liquid Properties
Type of Liquid Specific Gravity Sg at 60ºF Viscosity at 60ºF Centipose
10% Salt Water 1.07 1.40
Brine, 25% NaCl 1.19 2.20
Brine, 25% CaCl2 1.23 2.45
30º API Crude Oil 0.87 13.00
Average Fuel Oils 0.93 8.90
Kerosene 0.83 1.82
Auto Gasoline 0.72 1.20
Aviation Gasoline 0.70 0.46
50% Sodium Hydroxide (NaOH) 1.53 95.00
Mil 5624 Jet Fuels:
JP3 0.75 0.79
JP5 0.84 2.14
JP8 0.80 1.40
Acids: At 68ºF At 68ºF
60% Sulfuric (H2SO4) 1.50 6.40
98% Sulfuric (H2SO4) 1.83 24.50
85% Phosphoric (H2PO4) 1.69 12.00
37.5% Hydrochloric (HCl) 1.46 1.94


SE C T I O N 1 . F L OW P R OP E R T IES

C. Open Channel Flow D. Gas Flow
One of the most widely used, formulas for open-channel Fiber Glass Systems piping systems can be used in
flow is that of Robert Manning. This formula in Equation pressurized gas service when the pipe is buried at least
10 is useful in predicting the flow in open “gravity feed" fi- three feet deep.
berglass sewer lines. FGS software Success By Design In above ground applications, they can be
is recommended to perform these calculations. used provided the pressure does not exceed
the values shown below and further that the
pipe is properly safeguarded when conveying a
hazardous gas.
Eq. 10
Pipe
Diameter 1" 11/2" 2" 3" 4" 6" 8" 10" 12" 14" 16"
Where:
psig 25 25 25 25 25 25 14 9 6 5 4
Q = Flow rate in ft3/sec (m3/sec)
A = Flow cross sectional area, ft2 (m2) Consult your local Smith Fibercast representative for
Rh = Wetted perimeter, ft (m) safeguard procedures.
S = Hydraulic slope, dimensionless Since the inside diameter of Fiber Glass Systems pipe
S = H/L is smoother and larger than steel pipe of corresponding
nominal diameters, less frictional resistance is devel-
H = elevation change over the pipe length oped under turbulent flow conditions, resulting in greater
“L", ft (m) flow capacities. There are two basic equations used to
L = Length measured along the pipe, ft (m) calculate pressure loss for flow of gases. To determine
k = 1.49 (US Customary units, ft. & sec.) which equation is required, the transition flow rate must
be determined from Equations 12, 13 and 14. If the
k = 1.0 for flow in m3/sec. Use meter for A, desired flow rate is greater than the value calculated
Rh, & D. from equation 14, then the equations for fully turbulent or
n = 0.009 Manning’s constant for fiberglass rough pipe flow must be used. If the desired flow rate is
less than the value calculated from equation 14, then the
equation for partially turbulent or smooth pipe flow must
Eq. 11
be used.
Equations for transition flow rate:
Where:
D = Pipe inner diameter, ft (m)
U = Wet contact angle, radians
Eq. 12

Eq. 13

Eq. 14

Where QT = Transition Flow Rate

Eq. 15

(1) IGT Distribution Equations from American Gas Association Plastic Pipe
Handbook for Gas Service.



For fully turbulent or rough pipe flow:(1)
or

Eq. 16

For partially turbulent or smooth pipe flow(1)
or

Eq. 17

Where:

Eq. 18

D = Inside Diameter (in.)
G = Specific Gravity (S.G. of air = 1.0)
L = Length of Pipe Section (ft.)
Pb = Base Pressure (psia)
Pi = Inlet Pressure (psia)
Po = Outlet Pressure (psia)
Q = Flow Rate (MSCFH - thousand standard cubic ft.
per hr.)
Tb = Base Temperature (°R)
T = Temperature of Gas (°R)
Z = Compressibility Factor
m = Viscosity (lb./ft. sec.)
K = Absolute Roughness of Pipe =
0.00021 (in.) for Fiber Glass Systems pipe
°R = °F + 460°
m = (lb./ft. sec.) = m (centipoise) ÷ 1488
psia (Absolute) = psig (Gauge) + 14.7
FGS can perform computer calculations using the Success By
Design program to solve gas flow problems for: pipe size, Q,
Pi, or Po if the other variables are known.

TABLE 1.3 Typical Gas Properties
Specific Gravity Viscosity at 60°F
Type of Gas at 60°F(1) lb./ft. sec.
Air 1.02 .0000120
Carbon Dioxide 1.56 .0000098
Carbon Monoxide .99 .0000116
Chlorine 2.51 .0000087
Ethane 1.06 .0000060
Methane .57 .0000071
Natural Gas .64 .0000071
Nitrogen .99 .0000116
Nitrous Oxide 1.56 .0000096
Oxygen 1.13 .0000132
Sulfur Dioxide 2.27 .0000083

(1) All Specific Gravity based on air = 1.0 at 70° F.


SE C T I O N 2 . S U P P OR T S , A N C HORS and GUIDES

SECTION 2. Above Ground System Design - Supports, Anchors and Guides
Piping Support Design Support
Above ground piping systems may be designed as restrained Pipe supports hold the pipe in position and when properly
or unrestrained. Selection of the design method is depen- spaced prevent excessive deflections due to the weight of
dent on variables such as operating temperature, flow rates, the pipe, fluid, external insulation and other loads.
pressures and piping layout. System designs combining the
two methods often lead to the most structurally efficient and Anchor
economical piping layout. Pipe anchors restrain the pipe against axial movement or
applied forces. These forces may result from thermal loads,
Unrestrained System Design water hammer, vibrating equipment, or externally applied
The unrestrained system is often referred to as a “simple mechanical loads.
supported" design. It makes use of the inherent flexibility
of fiberglass pipe to safely absorb deflections and bending Guide
stresses. Simple pipe hangers or steel beams are used Pipe guides prevent lateral (side-to-side) movement of the
to provide vertical support to the pipe. These simple sup- pipe. Guides are required to prevent the pipe from buckling
ports allow the piping system to expand and contract free- under compressive loading. For example: When anchors
ly resulting in small axial stresses in the piping system. are used to control thermal expansion, guides are always
Long straight runs often employ changes-in-direction to required.
safely absorb movement due to thermal expansion and
contractions, flow rate changes, and internal pressure. A. Support Bracket Design

Experience has shown the use of too many simple pipe The hanger supports in Figure 2.0 must have sufficient
hangers in succession can result in an unstable line when contact areas to distribute the load. The preferred circum-
control valves operate and during pump start-up and shut- ferential contact is 180°. Refer to Table 2.0 for minimum
down. To avoid this condition the designer should incor- width requirements. When less than 180° of circumfer-
porate guides periodically in the line to add lateral stability. ence contact and/or larger diameters are encountered,
In most cases, the placement of lateral guides at intervals support saddles as shown in Figure 2.1 should be used.
of every second or third support location will provide ad-
equate stability. Axial stability in long pipe runs may be Design rod to allow
for axial and side
improved by the proper placement of a “Pipe Hanger with movement
Axial Guide" as shown in Figure 2.6. The project piping
engineer must determine the guide requirements for sys-
Spacer
tem stability.

Restrained System Design
The restrained system is often referred to as an “an-
chored and guided design". The low modulus of elastic- Clamp, snug
ity for fiberglass piping translates to significantly smaller but not tight
thermal forces when compared to steel. Anchors are
employed to restrain axial movement and provide ver- Figure 2.0
tical support in horizontal pipelines. Anchors used to
restrain thermal expansion create compressive forces in
the pipeline. These forces must be controlled by the use Note: Valid for Sg < 1.25
of pipe guides to prevent the pipe from buckling. In cases
where axial loads created by anchoring a pipe run are ex-
cessively high, the use of expansion loops or expansion
TABLE 2.0 Minimum Support Width
joints must be employed. When using anchors, the effect Pipe Size Class I Class II
of system contraction should be considered. See the (In.) (In.) (In.)
thermal analysis section for more thorough information
1 7
/8 7
/8
on handling thermal loads.
11/2 7
/8 7
/8
2 7
/8 7
/8
Fiberglass Piping System “Support" 3 11/4 11/4
Terminology 4 11/4 11/4
Fiberglass piping engineers use three basic structural com- 6 11/2 11/2
ponents to install a piping system. They are the support, 8 13/4 17/8
anchor, and guide. 10 13/4 25/8
12 2 31/4
14 2 4


S E CTION 2. SUPPORTS, ANCHORS and GU ID ES

Class I Products: CENTRICAST PLUS CL-2030, The substructure design should include the static weight
CENTRICAST PLUS RB-2530, CHEM THREAD, Z- of the pipe, fluid and any external loads such as insula-
CORE. Minimum required contact angle is 110° tion, wind, ice, snow, and seismic.

Class II Products: RED THREAD II, GREEN THREAD, Guide Design
SILVER STREAK, F-CHEM, CENTRICAST CL-1520,
CENTRICAST RB-1520. Minimum required contact an- B. Typical Guide Usage
gle is 170°
1. Between anchors to prevent buckling of pipeline at
Class III Products: GREEN THREAD 175/250 Marine elevated temperatures.
Offshore Products. Information is available in Bulletin 2. Near entry points of expansion joints and loops to
C3850. ensure proper functionality.
3. To provide system stability.
For sizes 16-24 inch, the support bracket bearing stress
should not exceed 50 lb/in2. The use of support saddles Properly designed and installed guides prevent the
with these pipe sizes is recommended. Refer to Figure pipe from sliding off support beams and allow the pipe
2.1. to freely move in the axial direction. Guides should
Support Saddle be used with 180° support saddles to reduce wear
Class 1 and abrasion of the pipe walls.
contact
angle = Figure 2.4 shows a
common method of Support with Guide
110°-120°.
Contact L guiding fiberglass pipe. 1/16" Min., 1/8" Max.
clearance per side
Angle A clearance of 1/16- to
Figure 2.1 1/8-inch is recommend-
ed between the guide
TABLE 2.1 Saddle Length and the wear saddle.
A 180° support “wear"
Pipe Size Class I Class II
(In.) (In.) (In.)
saddle is recommended
to prevent point contact
1 3 2 between the bolt and
11/2 3 2 pipe wall. The U-bolt Figure 2.4
2 4 4 should not be tightened
3 4 4 down onto the pipe. It
4 4 4 should be tightened to the structural support member us-
6 4 6 ing two nuts and appropriate washers. Clearance is rec-
8 5 5/8 8 ommended between the U-bolt and the top of the pipe.
10 8 3/8 10
12 8 3/8 12 Eight-inch diameter and larger pipe are generally allowed
14 8 3/8 14 more clearance than smaller sizes. The determination of
16-24 - (1)(2) acceptable clearance for these sizes is dependent on the
1. Use the pipe diameter as minimum saddle length. piping system and should be determined by the project
2. Refer to F-CHEM product bulletin for sizes greater than 24-inch piping engineer.
diameter.
Another design practice is to use U-straps made from flat
rolled steel instead of U-bolts. Flat U-straps are less apt
Typical applications using support saddles are shown in than U-bolts to “point" load the pipe wall. U-strap use is
Figures 2.2 & 2.3. The support saddles should be bonded to most common when guiding pipe sizes greater than 6-
the pipe wall. inches diameter.

When U-bolts are used in vertical piping, then two 180°
“wear" saddles should be used to protect the pipe around
its entire circumference. It is appropriate to gently snug
the U-bolt if a 1/8-inch thick rubber pad is positioned be-
tween the U-bolt and the saddle. If significant thermal
cycles are expected, then the U-bolts should be installed
with sufficient clearance to allow the pipe to expand and
contract freely. See the “Vertical Riser Clamps" section
for additional options in supporting vertical piping.
Figure 2.2 Figure 2.3



Pipe Hanger with Lateral Guide
as shown in Figures 2.5 and 2.6.
Maximum rod length allows
18" minimum The support widths for guided pipe hangers should meet
for axial movement
rod length the recommendations in Tables 2.0 & 2.1.

Spacer Vertical Riser Clamps
Riser clamps as shown in Figure 2.7 may act as simple
Lateral supports, as well as guides, depending upon how they
Auxiliary are attached to the substructure. The clamp should be
Guide
snug but not so tight as to damage the pipe wall. The
Clamp, snug use of an anchor sleeve bonded onto the pipe is required
but not tight to transfer the load from the pipe to the riser clamp. See
Figure 2.5 the “Anchor Designs" section for detailed information con-
cerning the an-
Figure 2.5 shows a more sophisticated pipe hanger and chor sleeve or
guide arrangement. It may be used without wear saddles FRP buildup. Riser Clamp
as long as the tie rod allows free axial movement. The
hanger must meet the width requirements in Table 2.0. If It is important Anchor
a clamp width does not meet the requirements in Table to note that this sleeve
2.0 or the pipe sizes are greater than 14-inch diameter, type of clamp or FRP
then support saddles should be used. See Table 2.1 for only provides buildup
support saddle sizing recommendations. upward verti- Clamp, snug
cal support. but not tight
Lateral loading on guides is generally negligible under Certain design Snug fit
normal operating conditions in unrestrained piping sys- layouts and op-
tems. In restrained piping systems, guides provide the erating condi- Figure 2.7
stability required to prevent buckling of pipelines under tions could lift
compressive loads. If the guides are located properly in the pipe off the
the pipeline, the loads required to prevent straight pipe riser clamp. This would result in a completely different
runs from buckling will be very small. load distribution on the piping system. A pipe designer
needs to consider whether the column will be under ten-
Upset conditions can result in significant lateral loads on sion, or in a state of compression. Additional guides may
the guides and should be considered during the design be required to prevent unwanted movement or deflection.
phase by a qualified piping engineer. Water hammer and
thermal expansion or contraction may cause lateral load- A qualified piping engineer should be consulted to ensure
ing on guides near changes in direction. Therefore, it is an adequate design.
always prudent to protect the pipe from point contact with
guides near changes in directions and side runs. Riser clamps designed to provide lateral support should
incorporate support saddles to distribute the lateral loads.
Pipe Hanger with Axial Guide

18" Minimum rod length allows
for lateral flexibility.
C. Anchor Design

Anchor Usage
Axial Guide
Spacer 1. To protect piping at “changes-in-directions" from ex-
cessive bending stresses.
2. To protect major branch connections from prima-
ry pipeline induced shears and bending moments.
Particular consideration should be given to saddle
and lateral fitting side runs.
Clamp, snug
3. Installed where fiberglass piping is connected to steel
but not tight
Figure 2.6 piping and interface conditions are unavailable.
4. To protect a piping system from undesirable move-
Figure 2.6 shows a pipe hanger with an axial guide using ment caused by water hammer.
a double bolt pipe clamp arrangement. This support pro- 5. To protect sensitive in-line equipment.
vides limited axial stability to unrestrained piping systems. 6. To absorb axial thrust at in-line reducer fittings when
fluid velocities exceed 7.5 ft/sec.
Pipe lines supported by long swinging hangers may eperi- 7. To provide stability in long straight runs of piping.
ence instability during rapid changes in fluid flow.
Stability of such lines benefit from the use of pipe guides


S E CTION 2. SUPPORTS, ANCHORS and G U ID ES

To be effective, an anchor must be attached to a sub- The anchor in Figure 2.9 will provide considerably less
structure capable of supporting the applied forces. In lateral stiffness than the anchor in Figure 2.8. The effect
practice, pumps, tanks, and other rigidly fixed equipment of lateral stiffness on the overall system stability should
function as anchors for fiberglass piping systems. always be considered when selecting an anchor design.

The anchor widths should meet the recommendations for
Restrains pipe movement in all directions support bracket designs in Table 2.0.

Anchor Sleeves The reactions generated at anchors when restraining
large thermal loads can be significant and should be
calculated by a qualified piping engineer. The anchors
Snug fit
brackets and substructure design should be designed
with sufficient stiffness and strength to withstand these
loads combined with any other system loads. Other sys-
Clamp, snug
but not tight tem loads may include water hammer, the static weight of
the pipe, fluid and any external loads such as insulation,
Weld or Bolt Anchor wind, ice, snow, and seismic.
to support member
Figure 2.8
Anchor Sleeves

Anchors as previously described are used to provide ax- An anchor sleeve as shown in Figure 2.12 is necessary to
ial restraint to piping systems. In most cases an anchor transfer axial load from a pipe body to an anchor bracket.
provides bi-directional lateral support to the pipe thus act- Pairs of anchor sleeves are bonded to the outer surface
ing like both a support and guide. Furthermore, anchors of a pipe to provide a shear load path around the com-
can be designed to provide partial or complete rotational plete circumference of the pipe body. To restrain pipe
restraint. But, this is not normally the case in practice. motion in two di-
Figures 2.8 through 2.11 show typical methods of anchor- rections, two pairs Anchor Sleeve
ing fiberglass piping systems. of anchor sleeves
are required. They
Restrains pipe movement in all directions must be bonded
Anchor on both sides of an
Sleeves anchor bracket to 180° Equal to Nom.
completely restrain Diameter of
Pipe
a pipe axially. Figure 2.12
There are design
Snug fit conditions where
Clamp, snug only one set of anchor sleeves is required. The piping
but not tight engineer should make this determination.

During installation the anchor sleeve end faces must be
Figure 2.9
aligned to mate precisely against the anchor brackets
when engaged. If only one of the two halves of an an-
Restrains pipe movement Restrains pipe movement chor sleeve contacts the anchor bracket, the loading will
in all directions in all directions and directly be off center or eccentric. Eccentric loading will increase
supports heavy fittings the shear stress on the contacted anchor sleeve. It may
Structural Steel
Anchor bolted also cause the pipe to rotate at the anchor resulting in un-
to Flange wanted deflections in the pipe. Refer to Figures 2.8 & 2.9
for typical configurations.

It is important to understand how the load is transferred
from the pipe to the anchor brackets. First the axial load
is sheared from the pipe wall into the anchor sleeves
through the adhesive bond. The load is then transferred
from the anchor sleeve by direct contact bearing stress
Structural Steel between the end of the anchor sleeve and the anchor
Column bracket which ultimately transfers it to the substructure.
Figure 2.10 Figure 2.11
Under no circumstances is the anchor to be tightened
down on the pipe surface and used as a friction clamp to
transfer load. The pipe should be free to slide until the



anchor sleeves contact the anchor bracket to transfer
Figure 2.13 Piping Span Adjustment Factors With
the load. Piping engineers often take advantage of this
anchoring procedure by allowing the pipe to slide a small Unsupported Fitting at Change in Direction
amount before contacting the anchor. This effectively Span Type Factor
reduces restrained loads.
a Continuous interior or fixed end spans 1.00
b Second span from simple supported 0.80
Split repair couplings, split fiberglass pipe sections or end or unsupported fitting
hand layups of fiberglass and resin are commonly used
c + d Sum of unsupported spans at fitting < 0.75*
as anchor sleeves. Contact your fiberglass distributor to
e Simple supported end span 0.67
determine the most appropriate choice for Fiber Glass
Systems’ wide variety of piping products.

D. Piping Support Span Design a e
a

b
A support span is the distance between two pipe sup-
ports. a

a
Proper support span lengths ensure the pipe deflections b

b
and bending stresses are within safe working limits. For
static weight loads, it is standard practice to limit the max- c

d
imum span deflection in horizontal pipe lines to Ω" and *For example: If continuous support span is 10 ft., c + d must not
the bending stresses to 1/8 of the ultimate allowable bend- exceed 7.5 ft. (c = 3 ft. and d = 4.5 ft. would satisfy this condition).
ing stress. Fiber Glass Systems applies these design
limits to the engineering analysis used to determine the
allowable support spans. Figure 2.14 Piping Span Adjustment Factors With
Supported Fitting at Change in Direction
Span Analysis Methodology
Span Type Factor
The maximum allowable piping support spans are deter- a Continuous interior or fixed end spans 1.00
mined using the “Three Moment Equations" for uniformly b Span at supported fitting or span adjacent 0.80
loaded continuous beams. The equations may be modi- to a simple supported end
fied to represent various end conditions, load types and e Simple supported end span 0.67
even support settlements. Refer to Appendix A for the
fundamental equations. Fiber Glass Systems uses these
equations to calculate the bending moments in piping
spans. The pipe bending stresses and deflections are a e
then evaluated for compliance with the aforementioned a

b
design criteria.
a

a
To avoid lengthy engineering calculations, FGS individu- a
a
al product bulletins contain recommended piping support
span lengths. These span lengths are easily modified to b
b

match fluid specific gravity, operating temperatures and
end conditions. Figures 2.13 and 2.14 provide span ad-
justment factors for various end conditions found in most Summary
horizontal piping system layouts. Tables for fluid specific 1. Do not exceed the recommended support span.
gravity and temperature adjustment factors are product 2. Support valves and heavy in-line equipment indepen-
unique. Please refer to Smith Fibercast’s product data dently. This applies to both vertical and horizontal
bulletins for detailed design information. piping.
3. Protect pipe from external abrasion.
FGS software Success By Design quickly calculates sup- 4. Avoid point contact loads.
port spans for uniformly loaded piping systems. Success 5. Avoid excessive bending. This applies to handling,
By Design takes into consideration product type, tem- transporting, initial layout, and final installed position.
perature, specific gravity, uniform external loads, and end 6. Avoid excessive vertical run loading. Vertical loads
conditions as shown in Figures 2.13 and 2.14. should be supported sufficiently to minimize bending
stresses at outlets or changes in direction.
Complex piping system designs and load conditions may 7. Provide adequate axial and lateral restraint to ensure
require detailed flexibility and stress analysis using finite line stability during rapid changes in flow.
element modeling. The project design engineer must
determine the degree of engineering analysis required for
the system at hand.


SECTION 3. TEM PERATURE EFF EC T S

SECTION 3. Temperature Effects on Fiberglass Pipe
System Design Thermal Properties & characteristics

The properly designed piping system provides safe and ef- The reaction of fiberglass piping to changes in temperature
ficient long-term performance under varying thermal environ- depends on two basic material properties, the thermal “coef-
ments. The system design dictates how a piping system will ficient of expansion"(a) and the axial moduli of elasticity. The
react to changes in operating temperatures. composite nature of fiberglass piping results in two distinctive
axial moduli of elasticity. They are the axial compression
The unrestrained piping system undergoes expansion and and axial tensile moduli. Systems installed at ambient tem-
contraction in proportion to changes in the pipe wall mean perature and operated at higher temperatures will generate
temperature. Fiberglass piping systems that operate at or internal compression piping stress when anchored. Although
near the installation temperature are normally unrestrained this is the most common engineering design condition, the
designs, where the most important design consideration is piping engineer should not overlook the opposite thermal
the basic support span spacing. Since few piping systems condition that generates tensile stresses.
operate under these conditions, some provisions must be
made for thermal expansion and contraction. The thermal properties of fiberglass pipe distinguish it from
steel in important ways. The coefficient of expansion is
The simplest unrestrained piping systems use directional roughly twice that of steel. This translates to twice the ther-
changes to provide flexibility to compensate for thermal mal movement of steel in unrestrained systems. The axial
movements. When directional changes are unavailable or compression modulus of elasticity of fiberglass pipe varies
provide insufficient flexibility, the use of expansion loops or from 3% to 10% that of steel. When restraining thermal
expansion joints should be designed into the system to pre- movements in fiberglass piping the anchor loads would be
vent overstressing the piping system. These systems are 1/5 or less than the loads created by a same size and wall
considered unrestrained even though partial anchoring and thickness in steel piping system.
guiding of the pipe is required for proper expansion joint, ex-
pansion loop performance and system stability. Thermoplastic pipe coefficients of expansion are typically
more than four times that of fiberglass. The elastic modu-
The fully restrained “anchored" piping system eliminates lus of thermoplastic piping is considerably smaller than the
axial thermal movement. Pipe and fittings generally ben- moduli of fiberglass and steel. The modulus of elasticity of
efit from reduced bending stresses at directional changes. thermoplastic pipe decreases rapidly as the temperatures
Restrained systems develop internal loads required to main- increases above 100°F. This results in very short support
tain equilibrium at the anchors due to temperature changes. spans at elevated temperatures. A restrained thermoplastic
When the pipe is in compression, these internal loads require piping systems operating at elevated temperatures is very
guided supports to keep the pipe straight. Thus, the com- susceptible to buckling thus requiring extensive guiding.
monly referred to name of restrained systems is “anchored
and guided". Anchored and guided systems have anchors It is important to properly determine the temperature gradi-
at the ends of straight runs that protect fittings from thermal ent. The gradient should be based on the pipeline tempera-
movement and stresses. ture at the time that the system is tied down or anchored. If
the operating temperature is above this temperature, then the
Anchors at directional changes (elbows and tees) transmit gradient is positive and conversely if it is less than this tem-
loads to the support substructure. Special attention should perature, then the gradient is negative. Many piping systems
be given to these loads by the piping engineer to ensure an will see both positive and negative temperature gradients
adequate substructure design. When anchors are used to that must be considered during the system design.
break up long straight runs, the loads between them and the
substructure are generally negligible. The axial restraining FGS software Success By Design performs thermal analy-
loads are simply balanced between the two opposing sides sis on fiberglass piping systems based on the methods dis-
of the pipeline at the anchor. cussed in this section. The benefits of using Success By
Design are not only ease of use, but increased analysis ac-
curacy. The software evaluates the fiberglass material prop-
erties at the actual operating temperatures, eliminating the
conservatism built into charts and tables designed to cover
worst case scenarios for all designs.


SE C T I O N 3 . T E MP E R A T U R E E FFECTS

Fundamental Thermal Analysis Formulas Flexibility Analysis and Design

A. Thermal Expansion and Contraction There are four basic methods of controlling thermal expan-
sion and contraction in above ground piping systems. They
The calculation of thermal expansion or contraction in are:
straight pipelines is easily accomplished using the follow-
ing equation. 1. Anchoring and Guiding
2. Directional Changes
Eq. 19 3. Expansion Loops
4. Mechanical Expansion Joints
Where:
d = Length change, in (m) The use of anchors and guides as discussed earlier depends
a = Thermal coefficient of expansion, in/in/°F (m/m/°C) on restraining thermal growth. Directional changes, expan-
L = Pipe length, in (m) sion loops and mechanical expansion joints use component
To = Operating temperature, °F (°C) flexibility to safely absorb thermal movements.
Ti = Installation temperature, °F (°C)
Final tie-in or completion temperature. A. Directional Change Design
(To - Ti) is the temperature gradient
The flexibility analysis of a directional change is based
B. Anchor Restraint Load on a guided cantilever beam model. The cantilever must
be of sufficient length to ensure the pipe will not be over-
The calculation of the restrained load in a pipeline be- stressed while absorbing the thermal movement. This is
tween two anchors is easily accomplished using the fol- accomplished by satisfying the following equations.
lowing equation.
Eq. 22 Based on pipe allowable bending stress
Eq. 20

Where:
Fr = Restraining force, lb (N)
a = Thermal coefficient of expansion, in/in/°F (m/m/°C)
A = Reinforced pipe wall cross sectional area, in2 (m2) Where:
To = Operating temperature, °F (°C)
Ti = Installation temperature, °F (°C) K = 3, Guided cantilever beam coefficient
Final tie-in or completion temperature. L = Length of cantilever leg, in (m)
(To - Ti) Temperature gradient E = Pipe beam bending modulus of elasticity,
E = Axial modulus of elasticity, lb/in2 (N/m2) lb/in2(N/m2)
The compression modulus should be used with a positive OD = Pipe outer diameter, in (m)
temperature change (To>Ti) and the tensile modulus with a
negative temperature change (To<Ti). d = Total deflection to be absorbed, in (m)
s = Pipe allowable bending stress, lb/in2(N/m2)
The reactions on the external support structure at inter-
nally spaced anchors in long straight runs are negligible Eq. 23 Based on fitting allowable bending moment
because the in-line forces balance. However, the an-
chors at the end of straight runs will transmit the full load
to the support structure.

C. Guide Spacing
Where:
The Guide spacing calculations are derived from Euler’s K = 6, Guided cantilever beam coefficient
critical elastic buckling equation for a slender column with L = Length of cantilever leg, in(m)
pivot ends. E = Pipe beam bending modulus of elasticity,
lb/in2(N/m2)
Eq. 21 I = Pipe reinforced area moment of inertia, in4(m4)
d = Total deflection to be absorbed, in(m)
M = Fitting allowable bending moment, in-lb (N-m)
Where:
Lg = Guide spacing, in (m)
Minor out of plane rotation of the elbow should be al-
Fr = Restraining force, lb (N) lowed to minimize bending moments on the elbow.
E = Bending modulus of elasticity, lb/in2 (N/m2)
I = Pipe area moment of inertia, in4 (m4) The use of the guided cantilever beam equation results in
p = Pi ~3.14159 conservative leg lengths.


SECTION 3. TEM PERATURE EFFEC T S

Horizontal Directional Change C. Expansion Joint Design
Mechanical expansion joint use requires the engineer
to determine the complete range of thermal movement
expected in the system. This is accomplished by cal-
culating the maximum thermal expansion and thermal
contraction for the operating conditions. The mechani-
cal expansion joint must be capable of absorbing the full
range of thermal movement with an appropriate margin
of safety. During installation the set position must be de-
termined to ensure the expansion joint will accommodate
the entire range of movement. This is accomplished us-
Figure 3.0 ing the following equation.

Eq. 24
See Figure 3.0 for a typical horizontal directional change
layout. Where:
Set Point = Installed position of mechanical expansion
B. Expansion Loop Design joint “Distance from the joint being fully
compressed", in(m)
The flexibility of an expansion loop is modeled using two Travel = Mechanical expansion joint maximum
equal length guided cantilever beams. Each cantilever movement, in(m)
absorbs half of the thermal expansion or contraction. The
cantilevers must be of sufficient length to ensure the pipe
and fittings will not be overstressed. Determination of the Eq. 25
minimum required lengths is accomplished by satisfying

equation 22 with K= 1.5 and equation 23 with K=3.
These equations should be used with the total deflection R = Thermal ratio
(d=d1+d2) to be absorbed by both expansion loop legs. Ti = Installation tie-in temperature, F°(C°)
Tmin = Minimum operating temperature, F°(C°)
See Figure 3.1 for a typical expansion loop layout. Tmax = Maximum operating temperature, F°(C°)
Tmin < Ti
The pipe should be guided into the expansion loop as
shown in Figure 3.1. The positioning of two guides on
each side of the expansion loop is required to maintain
proper alignment. The recommended guide spacing is Expansion Joint
four and fourteen nominal pipe diameters from the elbow Typical guides and supports require pads a shown when
for the first and second guides respectively. there is point contact. Supports can be snug or loose fitting
around the pipe. Guides must be loose.
To achieve the required flexibility only 90°elbows should First guide, 4 diameters distance from
expansion joint. Second guide, 14 di-
be used in directional changes and expansion loops. The ameters distance from expansion joint.
substitution of 45° elbows will result in an unsatisfactory
design.

Figure 3.2

Figure 3.1 L/2

L

d1 d2

First Guide
Anchor Second Guide Anchor
Length
Length


SE C T I O N 3 . T E MP E R A T U R E E FFECTS

Example Problem: For stagnant flow, the temperature of the fluid and inner
surface of the pipe can be assumed to equal the trace
Determine the “Travel" and “Set Point" for the following temperature. This assumption is valid if the heat trace el-
conditions. ement provides sufficient energy to overcome heat losses
to the environment. For the stagnant or no flow condition,
Ti = 75°F, Tmin = 45°F, Tmax = 145°F, R = 0.3 equations 26 and 27 are used to determine the maximum
Pipe total thermal movement is 6 inches. allowable heat trace temperature.
Design factor 1.5
Eq. 29
Expansion joint “Travel" required is 9 inches (6 x 1.5).
The “Set Point" should be 0.3 x 9 = 2.7 inches (compres- Therefore:
sion). This set point allows for 1.5 times the thermal
growth or contraction for the given operating conditions. Eq. 30
See Figure 3.2 for a typical expansion joint layout.
For Eq. 26-30:
The proper selection of an expansion joint design de-
pends on the available activation forces generated by the Pipe inner surface temperature, °F(°C)
piping system. Equation 20 should be used to determine
the fully restrained activation force capability of the piping Heat trace element temperature, °F(°C)
system. If a mechanical expansion joint requires an acti-
vation load higher than the fully restrained activation force Pipe temperature rating, °F(°C)
then the expansion joint will not function. The expansion
joint activation force in practice should not exceed 1/4 of Chemical resistance temperature rating
the loads in a fully restrained piping system. Mechanical
of pipe, °F(°C)
expansion joint requiring higher activation forces may not
provide sufficient flexibility to warrant its use. Determination of the pipe inner wall temperature under
active flow conditions depends on flow rate, specific heat
It is prudent engineering practice to determine if the pip- of the fluid, temperature of fluid entering pipe, conduction
ing system will require guiding under the compression ac- through the pipe wall, external environmental heat losses
tivation forces. Equation 21 should be used to determine and the heating element capacity. The complexity of this
the guide spacing. analysis is beyond the scope of this manual. Therefore,
prudent engineering practices should be employed to de-
D. Heat Tracing termine the safe heat tracing temperatures under these
conditions.
Heat tracing is the practice of heating a piping system
to prevent freezing or cooling of a process line. Steam These criteria are most easily explained by the following
tracing and electrical heat tapes are typical methods of examples:
heat tracing fiberglass piping. The maximum heat tracing
temperature is governed by one of three criteria: Example: What is the maximum heat tracing tempera-
ture allowed to maintain a 5% caustic solution at 95°F
(1) The mean wall temperature must not exceed the inside RED THREAD II pipe rated to 210°F?
maximum temperature rating of the pipe,
The three governing criteria must be considered in order
to determine the maximum tracing element temperature.
Eq. 26
Step I: Solving for criterion (1) equation 26 is applied.

(2) The maximum tracing element temperature must not
exceed 100°F(55.6C°) above the temperature rating of
the pipe

Eq. 27

(3) The maximum recommended temperature for the Rearranging and solving for the maximum trace tempera-
service chemical must not be exceeded at the surface of ture, Tra we get 325°F.
the pipe inner wall.

Eq. 28


SECTION 3. TEM PERATURE EF F EC T S

Step II: Solving for criterion (2) equation 27 is applied. F. Thermal Expansion in Buried Pipe

Soil restraint inherently restrains movement of buried
fiberglass pipelines because these pipes develop rela-
tively small forces during a temperature change. Special
precautions (thrust blocks, guides, expansion joints, etc.)
for handling thermal expansion are not necessary if the
pipe is buried at least two to three feet and the bedding
Rearranging and solving for the maximum trace tempera- material is of a soil type capable of restraining the line.
ture, Tra we get 310°F. Sand, loam, clay, silt, crushed rock and gravel are suit-
able bedding for restraining a pipeline; however, special
Step III: Solving for criterion (3) equation 30 the stagnant precautions must be taken to properly anchor the pipe in
flow condition is applied. swamps, bogs, etc. where bedding might easily shift and
yield to even the low forces developed in fiberglass pipe.

G. Pipe Torque Due to Thermal Expansion
Therefore the maximum allowable heat trace temperature
equals the maximum chemical resistance temperature Torsion shear stresses in piping systems containing mul-
for the piping. Referencing FGS, Chemical Resistance tiple elevation and directional changes normally do not
Guide, Bulletin No. E5615, RED THREAD II pipe is rated have to be considered in pipe analysis. The allowable
to 100°F in 5% caustic. Therefore the maximum heat bending moments are much lower than the allowable
trace temperature is 100°F. torsional moments in a pipe. Therefore, bending mo-
ments in a pipe leg reacted by torsion in a connecting
However, if the fluid were flowing into the pipeline at tem- pipe will be limited by the bending moment capability of
peratures below 100°F, then the heat trace temperature the pipe not the torsional load. Computer modeling is
would be higher than 100°F. A thorough heat transfer recommended for this sophisticated level of piping sys-
analysis would be required to determine the appropriate tem analysis.
heat trace temperature for this condition.

The maximum heat trace temperature for stagnant flow is
100°F, the lowest temperature calculated using the three
criteria.

E. Thermal Conductivity - Heat Gain or Los

The thermal conductivity of fiberglass piping is approxi-
mately 1/100 that of steel, making it a poor conductor of
heat compared to steel. However, the use of insulation
to prevent heat loss or gain is recommended when there
are economic consequences due to heat loss or gain.
Typical fiberglass thermal conductivity values vary from
0.07-0.29 BTU/(Ft.)(Hr.)(°F).


SE C T I O N 4 . P IP E B U R IAL

SECTION 4. Pipe Burial
Introduction Burial Analysis

The guidelines in this section pertain to the design and burial Pipe burial depth calculations are based on Spangler’s de-
of fiberglass pipe. The structural design process assumes flection equation and Von Mise’s buckling equation as out-
the pipe will receive adequate support in typically encoun- lined in AWWA M45. Application of these methods is based
tered soil conditions. Recommendations for trenching, se- on the assumption that the design values used for bedding,
lecting, placing and compacting backfill will be discussed. backfill and compaction levels will be achieved with good
field practice and appropriate equipment. If these assump-
The successful installation depends on all components work- tions are not met, the deflections can be higher or lower than
ing together to form a sound support system. Therefore, predicted by calculation.
once a pipe is selected, it is of utmost importance to carefully
review the native soil conditions, select the backfill material A. Soil Types
and closely monitor the trenching and installation process.
Properly positioned and compacted bedding and backfill re- A soil’s ability to support pipe depends on the type of soil,
duces pipe deformations maximizing long-term performance degree of compaction and condition of the soil, i.e. den-
of a buried pipeline. sity and moisture content. A stable soil is capable of pro-
viding sufficient long-term bearing resistance to support
Detailed design and installation data for buried fiberglass pip- a buried pipe. Unstable soils such as peat, organic soil,
ing systems may be found in AWWA M45, Manual of Water and highly expansive clays exhibit a significant change
Supply Practices, Fiberglass Pipe Design, First Edition. in volume with a change in moisture content. Special
Contact Fiber Glass Systems applications engineer for de- trenching and backfill requirements are necessary when
tailed burial calculations. the native soil is unstable. Some guidelines to aid the
engineer in determining the stability at a particular site
Pipe Flexibility follow:

The response of fiberglass pipe to burial loads is highly de- 1. For cohesive soils or granular-cohesive soils, if the
pendent on the flexibility of the pipe walls. The best measure unconfined compressive strength per ASTM D2166
of pipe flexibility can be found using the “pipe stiffness" value exceeds 1,500 lb/ft2, the soil will generally be stable.
as defined and determined by ASTM D2412 tests.
2. For cohesive soils, if the shear strength of the soil
Pipe with pipe stiffness values greater than 72 psi typically per ASTM D2573 is in excess of 750 lb/ft2, the soil
resist native backfill loads with minimal pipe deformation. will generally be stable.
The pipe stiffness of small diameter fiberglass pipe, 1 to 8
inch diameters, typically meets or exceeds 72 psi. Two to 3. For sand, if the standard penetration “Blow" value,
three feet of native backfill cover with a soil modulus greater N, is above 10, the soil will generally be stable.
than or equal to 1,000 psi is generally sufficient to protect this
category of pipe from HS-20 vehicular and dead weight soil Soils types are grouped into “stiffness categories" (SC).
loads. They are designated SC1 through SC5. SC1 indicates
a soil that provides the highest soil stiffness at any given
Pipe that is buried under concrete or asphalt roadways that Proctor density. An SC1 classified soil requires the least
support vehicular loads requires less cover. Design data amount of compaction to achieve the desired soil stiff-
and burial depth recommendation for specific piping can be ness. The higher numbered soil classifications (SC2-
found in Smith Fibercast product bulletins and installation SC4) become, the more compaction is required to obtain
handbooks. Smith Fibercast’s Manual No. B2160 contains specific soil stiffness at a given Proctor density. The SC5
special installation instructions for UL Listed RED THREAD soils are unstable and should not be used as backfill or
IIA piping commonly used under pavements. bedding. Decaying organic waste and frozen materials
fall in the SC5 category. Lists of recommended backfill
Pipe with pipe stiffness values less than 72 psi, are consid- materials are shown in Table 4.0.
ered flexible and are more susceptible to the effects of poor
compaction or soil conditions. Because of this, larger diam-
eter piping requires detailed attention during the design and
installation of buried pipelines.


SECTION 4. PIPE B U R IAL

TABLE 4.0 Recommended Bedding and Backfill Materials
1 AWWA M45 soil stiffness categories
Stiffness Degree of Compaction3
Category1 Pipe Zone Backfill Material 2,5 % 2 Maximum particle size of æ inch for
4 all types.
SC1 Crushed rock with <15% sand, maximum 25% As Dumped
passing the 3/8” sieve and maximum 5% fines (No compaction required) 3 Compaction to achieve a soil
modulus of 1,000 psi.
SC2 Coarse-grained soils with < 12% fines 75-85
SC3 Coarse-grained soils with >12% fines 85-95 4 Pea gravel is a suitable alternative.

SC3 Fine-grained soils with >12% fines 85-95 5 A permeable fabric trench liner may
be required where significant ground
SC4 Fine-grain soils with medium to no plasticity >95 water flow is anticipated.
with <30% coarse-grained particles

B. Soil Modulus Considerations
TABLE 4.1 Nominal Trench Widths
The soil modulus is a common variable that is very impor- Pipe Size Minimum Width Maximum Width*
tant to fiberglass piping burial analysis regardless of the (In.) (In.) (In.)
soil type. Extensive research and engineering analysis 2 18 26
has shown that a soil modulus of 1,000 psi provides very 3 18 27
good support to fiberglass pipe. Table 4.0 shows the
4 18 28
degree of compaction based on the Proctor density to ob-
6 20 30
tain a soil modulus of 1,000 psi. It is worth noting that for
8 23 32
all stiffness categories this soil modulus may be obtained,
although with varying compaction requirements. 10 25 34
12 28 36
Although a modulus of 1,000 psi is preferred, values as 14 31 38
low as 750 psi will provide sufficient support to fiberglass 16 33 40
pipe if it is properly engineered and installed. 18 36 42
20 39 44
24 44 48
30 52 56
Trench Excavation and Preparation
36 60 64
42 66 70
A. Trench Size
48 72 80
The purpose of the trench is to provide working space 54 78 86
to easily install the pipeline. The trench depth must ac- 60 84 96
count for the bedding thickness, pipe height and backfill 72 96 108
cover. Trench widths must accommodate workers and 84 108 120
their tools, as well as allow for side bedding and backfill. * Trench widths may be wider depending on soil conditions.
Nominal trench widths listed in Table 4.1 are satisfactory
for most installations.
Trench for Soft and Medium Consistency Soils
B. Trench Construction
See Compacted
Table 4.1 Native Backfill
1. Solid rock conditions

If solid rock is encountered during trench construction,
Permanent
the depth and width of the trench must be sufficient to Shoring
allow a minimum of 6-inches of bedding between the Material
rock and pipe surface. Select
Bedding & Backfill
Material
2. Granular or loose soils
Figure 4.0
These types of soils are characterized by relatively
high displacement under load, and soft to medium soft
consistencies. The walls of trenches in this type of soil
usually have to be sheeted or shored, or the trench deformation in the pipe sides (see figures 4.0 & 4.1).
made wide enough to place a substantial amount In some cases, additional depth or supplementary
of bedding material in order to prevent excessive trench foundation material may be required.


SE C T I O N 4 . P IP E B U R IAL

Trench for Granular Type Soils C. Maximum Burial Depth

Trench shape where angle of repose Surface loads do not usually affect the maximum burial
of soil will not allow vertical walls depths. The maximum burial depth ultimately depends on
Compacted Native Fill the soil backfill modulus. When burying pipe in stable soil
with a backfill modulus of 1,000 psi, the maximum allow-
able depth of cover is normally 15-20 feet. When burying
pipe in soil with a backfill modulus of 700 psi, the maxi-
mum allowable cover is seven feet. Although the above
Select maximum burial depths are typical, Smith Fibercast will
Bedding & design custom products for your application. Reference
Backfill Material Smith Fibercast’s product bulletins for specific product
Figure 4.1 recommendations.

D. Roadway Crossing
3. Unstable soils
Pipe passing under unpaved roadways should be protect-
Unstable soils require special precautions to develop ed from vehicular loads and roadbed settlement. Burial
a stable environment for fiberglass pipe. See Figure depths under stable roadbeds should be determined per
4.2 for a recommended trenching procedure. SC1 AWWA M45 for vehicular traffic. If the roadbed is un-
bedding and backfill material should be used with a stable or burial-depths are shallow then steel or concrete
permeable, fabric liner to prevent migration of fill into sleeves are required see Figure 4.3.
the native soil. Due to the unpredictable nature of un-
stable soils a soils engineer should be consulted for
project specific design recommendations. Typical Roadway Crossing

Figure 4.3
Wide Trench for Very Soft or Unstable Soils

Compacted
Natural
Backfill

Trench
6" Min. Line with
Permeable, Protective Pad Between Steel or
Select Pipe and Conduit
Fabric Liner Concrete Sleeve
Bedding
Material 6" Min. Material
(SC1 only, Supplementary
See Table Trench Foundation
4.0 (if required)
Figure 4.2


SECTION 4. PIPE BU R IAL

BEDDING AND BACKFILL If excavated native material meets the requirements list-
ed in Table 4.0, it may be used for bedding and backfill.
A. Trench bottom Soils containing large amounts of organic material or fro-
zen materials should not be used. If there is any ques-
The trench bottom is the foundation of the pipe support tion as to the suitability of the native soil, a soil engineer
system. Select bedding material is required for flexible should be consulted.
fiberglass pipelines. The bedding should be shaped to
conform to the bottom º pipe diameter. Proper placement C. Backfill cover
and compaction of the bedding is required to ensure con-
tinuous pipe support. See Figures 4.4, 4.5 & 4.6 for ex- The cover layers above the backfill should be applied in
amples of standard bedding practices. lifts of 6 inches. Native soil may be used, provided it is
not unstable type SC5 soil. This includes soils loaded
with organic material or frozen earth and ice. Each lift
should be compacted to a Proctor Density to achieve a
Proper Bedding Improper Bedding 1,000-psi modulus per Table 4.0. Lifts applied 18 inches
or more above the top of the pipe may be applied in 12-
inch layers provided there are not chunks of soil larger
than 12 inches. Again, each layer is to be compacted to
the required density. Lift heights should never exceed
the capacity of the compaction equipment.

Heavy machinery should not be allowed to cross over
trenches unless completely covered and compacted.

D. High water table

Figure 4.4 Figure 4.5 Areas with permanent high water tables are usually co-
incident with very poor soil conditions. In most of these
areas, it will be necessary to use crushed rock or pea
Bedding and Backfill for Firm or gravel as the bedding and backfill material. In addition,
Hard Native Soil permeable fabric trench liner should be used to prevent
migration of the fill material into the native soil. In ex-
treme cases such as soft clay and other plastic soils, it
will be necessary to use “Class A" bedding. (See Figure
4.7). Also, if the depth of the pipe and the depth of cover
is less than one diameter, tie downs or concrete encase-
ment is recommended in sufficient quantity to prevent
flotation.

Areas prone to flooding or poor draining soil should be
treated similar to high water table areas.
Figure 4.6

Class “A" Bedding
B. Backfill materials

Backfill material at the sides of the pipe is to be added in
lifts, not to exceed 6-inches at a time, mechanically com-
pacted to the required density and continued to 6-inches
above the top of the pipe. The degree of compaction
is dependent upon the type of fill material used. Water
flooding for compaction is not recommended, nor is com-
pacting the fill material while it is highly saturated with
water.

Proper compaction of the backfill material is required
for pipeline stability and longevity. Sand, pea gravel or
crushed rocks are the recommended fill materials for
Fiber Glass Systems pipe compacted per Table 4.0.


SE C T I O N 5 . OT H E R C ON S ID E RATIONS

SECTION 5. Other Considerations

A. Abrasive Fluids grout material such as if manufactured by ITW Devcon
Corporation, Danvers, MA. Fiberglass piping systems
Fiber Glass Systems piping systems are used to convey should be designed with sufficient flexibility near wall pen-
abrasive fluids that may also be corrosive. Since fiber- etrations to minimize reactions to slight wall movements.
glass pipe does not depend upon a protective oxide film To prevent leakage around the grout, it is common to
for corrosion resistance, it is not subject to the combina- embed a steel sleeve with a water-stop during the wall
tion of corrosion and abrasion that occurs with metals. construction (Figure 5.0).

The effects of abrasive fluids on any piping system are The use of flexible seals between the pipe and wall pen-
difficult to predict without test spools or case history in- etration is a standard practice used to protect fiberglass
formation. Particle size, density, hardness, shape, fluid pipe from abrasion and minimize effects of wall move-
velocity, percent solids, and system configuration are ments. A segmented rubber seal such as Link-Seal®
some of the variables that affect abrasion rates. Standard manufactured by Thunderline/Link-Seal, 19500 victor
fiberglass piping with a resin-rich liner can generally han- Parkway, Suite 275, Livonia, MI 48152 is commonly used
dle particle sizes less than 100 mesh (150 micron) at flow with fiberglass pipe. When available, O-ring sealed joints
rates up to 8 ft./sec. The abrasion resistance can be im- may be incorporated into the piping system at wall pen-
proved by adding fillers such as fine silica, silicon carbide, etrations as shown in Figure 5.1.
or ceramic to the abrasion barrier (such as with SILVER
STREAK, F-CHEM, and CERAM CORE products). Wear
Pipe Penetrating Concrete
resistance of fiberglass fittings can be improved by using
long-radius fittings.

Since each abrasive service application is different and
peculiar to its industry, please consult your local Fiber
Glass Systems representative for a recommendation.

B. Low Temperature Applications

Fiberglass pipe is manufactured with thermosetting resin
systems that do not become brittle at low temperatures,
as do thermoplastic materials. Fiber Glass Systems pipe
Figure 5.1
and fittings can be used for low temperature applications
such as liquid gases (refer to Bulletin No. E5615 for com-
patibility with liquid gases). Tensile tests performed at If the pipe is not sealed into the wall, it must be protected
-75°F(-59.4°C) actually show an increase in strength and from surface abrasion. A heavy gage sheet metal sleeve
modulus. Typical low temperature applications are the will provide sufficient protection.
conveyance of fuel, oil, and other petroleum production
applications in Alaska. D. Pipe Bending

C. Pipe Passing through Walls or Concrete Pipe is often bent during transportation, handling and
Structures during installation to match trenching contours, etc. As
long as the minimum bending radius is not exceeded,
The design of wall Pipe Passing through these practices will not harm the pipe. Minimum bending
penetrations must Concrete Wall radius values are unique to product type and diameter.
consider the pos- Therefore, Smith Fibercast piping bulletins must be re-
sible effects of wall ferred to for accurate data.
settlement and the
resulting reactions Bending of pipe with in-line saddles, tees, or laterals
on the pipe body. should be avoided. Bending moments in the pipe will
Wall penetra- create undesirable stresses on the bonded joints and
tions below grade fittings.
must also be
sealed to prevent
water seepage.
Typically fiberglass
pipe is sealed into ® Link-Seal is registered trademark of Thunderline/Link-Seal
the wall open- Figure 5.0
ing with an epoxy


SECTION 5. OTHER CONSIDER A T ION S

E. Static Electricity • The maximum steam pressure does not exceed 15 psig
corresponding to a steam saturation temperature of ap-
The generation of static electricity is not a problem in proximately 250°F. Contact a factory representative for
most industrial applications. The effects of static electric- specific product design information.
ity usually become a design problem only if a dry, electri-
cally non-conductive gas or liquid is piped at high velocity • The piping system design must consider the effects of
through an ungrounded system. the steam cleaning temperatures. In most cases the
support spans will be reduced 15-35%.
The generation of static electricity under fluid flow condi-
tions is primarily related to the flow rate, ionic content of • Contact the factory before steam cleaning vinyl ester or
the fluid, material turbulence, and surface area at the in- polyester pipe.
terface of the fluid and the pipe. The rate of electrostatic
generation in a pipe increases with increasing length of G. Thrust Blocks
pipe to a maximum limiting value. This maximum limit-
ing value is related to fluid velocity and is greater for high Thrust blocks are not typically required for bonded piping
velocities. Highly refined hydrocarbons, such as jet fuels, systems capable of restraining thrust loads. FGS large
accumulate charges more rapidly than more conductive diameter F-CHEM O-ring pipe is not restrained and may
hydrocarbons, such as gasoline. However, the rate of require the use of thrust blocks. Consult the factory for
charge buildup in buried Smith Fibercast piping systems specific recommendations.
handling jet fuels at a maximum flow velocity of 5 ft/sec is
such that special grounding is not necessary. H. Vacuum Service

Static charges are generated at approximately the same Vacuum service may be a system design condition, or
rate in fiberglass piping and metallic pipe. The differ- it may occur as the result of an inadvertent condition.
ence in the two systems is that the charge can be more Sudden pump shut off, valve closures, slug flow and sys-
easily drained from a metal line than from a fiberglass tem drain down are examples of flow conditions that re-
line. Under the operating conditions encountered in most sult in vacuum. They should always be considered dur-
industrial applications, any static charge generated is ing the design phase. Regardless of the source, vacuum
readily drained away from the pipe at hangers or by other conditions result when the external atmospheric pressure
contact with the ground, and any small charge in the fluid exceeds the internal pressure. The pipe wall must be
is drained away at metallic valves and/or instrumentation capable of resisting this external pressure without buck-
lines. ling. Fiber Glass Systems’ product bulletins should be
consulted for specific external pressure (vacuum) ratings.
Fiber Glass Systems manufactures an electrically con- Large diameter pipe through 72-inches manufactured
ductive piping system that should be employed when specifically for vacuum conditions are available upon re-
static electricity is a critical design parameter. quest.

Occasionally in piping a dry gas at high velocity, I. Valves
a charge may build up on an ungrounded valve.
If this charge is not drained off by humid air, it When using valves with fiberglass piping products, con-
can shock personnel who come in contact with the valve. sideration must be given to the corrosion resistance of
This situation can be easily remedied by grounding the the valve with respect to the fluid being conveyed and the
valve. external environment. Valves should be independently
supported to reduce bending loads on the adjacent pipe.
Bulk fuel-loading facilities, because of high fluid Flanged valves mated to molded fiberglass flanges must
velocities, present a problem to both metallic have a full flat face to prevent overstressing the flanges.
and fiberglass pipe. Filters and other high sur- To ensure a good seal, use a 1/8-inch thick full-face, 60-
face area devices are prolific generators of static electricity at 70-durometer gasket between the valve sealing surface
these facilities. Special grounding procedures may be nec- and the fiberglass flange for up to 14-inch diameter pipe.
essary under these conditions. Use º-inch thick gaskets on larger sizes. If the valves do
not have full flat faces consult installation manuals for ad-
F. Steam Cleaning ditional recommendations.
Short duration steam cleaning of epoxy fiberglass pipe is
acceptable provided the following recommendations are J. Vibration
adhered to:
Low amplitude vibrations such as those produced by
• The piping system must be open-ended to prevent pres- well-anchored centrifugal pumps will have little effect on
sure buildup. Smith Fibercast piping. Such vibrations will be damp-
ened and absorbed by the relatively low modulus pipe.


SE C T I O N 5 . OT H E R C ON S ID E RATIONS

However, care must be taken to protect the exterior of the exposed fibers will be abraded with time, it is highly rec-
pipe from surfaces that might abrade and wear through ommended that surface be protected. Painting the pipe
the pipe wall over a long period of time. This can be ac- with a good quality acrylic or solvent-based paint is useful
complished by applying protective sleeves to the pipe at in blocking UV radiation.
the first two or three supports or padding these supports
with 1/8-inch rubber gasket material. M. Fungal, Bacterial, and Rodent Resistance

High amplitude vibration from pumps or other equipment Some plastics (thermoplastics) are subject to fungal, bac-
must be isolated from the piping system by flexible con- terial, and/or rodent attack, but fiberglass pipe offers no
nectors. nourishment or attraction to these annoyances. Under
stagnant conditions, some marine growths will attach to
K. Fluid Hammer fiberglass surfaces, but they do not attack or bore into
the pipe and are usually easily removed. Note regard-
A moving column of fluid has momentum proportional to ing zebra mussels: It was recently reported that a utility
its mass and velocity. When flow is abruptly stopped, compared zebra mussel growth in similar metal and fiber-
the fluid momentum is converted into an impulse or high- glass intake lines at the same location. Only two liters
pressure surge. The higher the liquid velocity and longer of zebra mussels were removed from the fiberglass line,
the pipe line, the larger the impulse. while two dumpster loads of mussels were removed from
a metal line.
These impulse loads can be of sufficient magnitude to
damage pipe, fittings and valves. N. FLANGE CONNECTIONS

Smith Fibercast flanges are designed to meet ANSI B16.5

Accurate determination of impulse loads is very
complex and typically requires computer model- Class 150 bolt hole standards. Alternate bolt hole stan-
ing of the piping system. However, the Talbot dards are available. Smith Fibercast flanges are de-
equation, given in Appendix A, may be used to calculate signed for 1/8 inch thick gaskets made from materials with
theoretical impulses assuming an instantaneous change a 60-70 durometer Shore A hardness. The use of flat
in velocity. Although, it is physically impossible to close washers under nuts and bolt heads is required. Refer to
a valve instantaneously, Talbot’s equation is often em- the appropriate product specific fittings bulletin for recom-
ployed to calculate worst cast conditions. mended bolt torque values.

In the real world quick reacting valves, reverse flow into Raised Face Flange Connections
check valves and sudden variations in pump flow rates
will cause water hammer surges. Engineers typically Special mating requirements exist when connecting flat-
incorporate slow operating valves, surge tanks and soft- face compression molded fiberglass flanges to raised-
starting pumps into piping systems to minimize fluid ham- face metallic flanges or valves having partial liner facings.
mer. Piping systems that experience surge conditions The addition of a metallic spacer ring placed between the
should be restrained to prevent excessive movement. raised face and the outer edge of the flange to form a
full flat-face on the mating flange is recommended. The
If the system operating pressure plus the peak surge purpose of the spacer ring is to fill the gap outside the
pressure exceeds the system pressure rating, then a raised-face to prevent bolt loads from bending and break-
higher pressure class piping system should be employed. ing the fiberglass flange. An alternative to the spacer
ring is the use of metallic back-up rings behind molded
L. Ultraviolet (U.V.) Radiation and Weathering fiberglass flanges. Filament wound flanges may be con-
nected directly to raised-face flanges without the use of
Fiberglass pipe undergoes changes in appearance when spacer rings.
exposed to sunlight. This is a surface phenomenon
caused by U.V. degradation of the resin. The degrada- Lug and Wafer Valves
tion depends upon the accumulated exposure and the
intensity of the sunlight. Long-term surface degradation Lined lug and wafer valves that use integral seals, use
may expose the outer layer of glass fibers; this condition a 1/4" steel spacer plate with an inner diameter equal to
is called “fiber-blooming". These exposed glass fibers Schedule 40 steel or as required by the valve manufac-
will block and reflect a significant portion of ultraviolet turer. The spacer plate outer diameter should match the
radiation resulting in a slower rate of degradation. This fiberglass flange outer diameter.
minimizes future damage to the remaining pipe wall.
Because Fiber Glass Systems pipe bodies are designed Unlined lug and wafer valves without integral seals may
with significant safety factors, minor fiber blooming does be directly connected to fiberglass filament flanges with-
not prevent the pipe from safely performing at its pub- out back up rings or to molded flanges with metal back-
lished pressure rating. If service conditions are such that up rings.


S ECTION 6. SPECIFICATIONS and APPR OVALS

SECTION 6. Specifications and Approvals
A. Compliance with National Specifications ASTM D4024 (See Table 6.1)
“Standard Specification for Machine Made ‘Fiberglass’
American Petroleum Institute (Glass-Fiber-Reinforced Thermosetting-Resin)
API Specification 15LR Flanges"
RED THREAD II Pipe & Fittings, 8"-16" Cyclic Design Designation Codes at 73.4°F, by flange size, are avail-
able in product bulletins.

American Society for Testing & Materials (ASTM) B. Approvals, Listings, and Compliance with
Regulations
ASTM D2310 (See Table 6.0 & 6.2)
“Standard Classification for Machine Made ‘Fiberglass’ American Water Works Association
(Glass-Fiber-Reinforced Thermosetting-Resin) Pipe" RED THREAD II pipe, GREEN THREAD pipe, and F-
Classifications of Pipe at 73.4°F are: CHEM pipe can be made in compliance with AWWA M45
for use as pressure pipes for water distribution (includ-
ing services) and transmission systems for both above
and below ground installations. When ordering, specify
TABLE 6.0 ASTM D2310 Classification AWWA M45.

ASME/ANSI B31.3
Pipe Size ASTM D2310
“Chemical Plant and Petroleum Refinery Pipe Code"
Classification
RED THREAD II and GREEN THREAD pipe that are
RED THREAD II 2”-3” RTRP-11AF manufactured in compliance with ASTM D2996, and
4”-24” RTRP-A11AH CENTRICAST pipe manufactured in compliance with
GREEN THREAD 1”-16” RTRP-11FF D2997, can be installed in compliance with ASME/ANSI
B31.3.
Z-CORE 1”-8” RTRP-21CO
SILVER STREAK 2”-48” RTRP-11FF Factory Mutual
CERAM CORE 6”-16” RTRP-11CF Pipe and fittings, sizes 4"-16", are available with Factory
Mutual approval for underground fire protection piping
F-CHEM 1”-72” RTRT-12EU
systems; pressure ratings to 200 psig. When ordering,
CENTRICAST: specify Factory Mutual Products.
RB-1520 11/2”-14” RTRP-21CW
RB-2530 1”-14” RTRP-21CW Food and Drug Administration
CL-1520 11/2”-14” RTRP-22BT The resins and curing agents used in the manufacture of
CL-2030 1”-14” RTRP-22BS RED THREAD II Pipe and Fittings and GREEN THREAD
Pipe and Fittings are defined as acceptable with the U.S.
* Static HDB Food, Drug, and Cosmetic Act as listed under 21 CFR
Part 177 Subpart C Section 177.2280 and 21 CFR Part
ASTM D2996 175 Subpart C Section 175.300.
“Standard Specification for Filament-Wound
‘Fiberglass’ (Glass-Fiber-Reinforced Thermosetting- Military Specifications
Resin) Pipe" MIL-P-29206 or MIL-P-29206A—RED THREAD II JP and
Designation Codes are available in product bulletins. GREEN THREAD JP pipe and fittings, sizes 2"-12", are
certified to be in compliance with MIL-P-29206 or MIL-P-
ASTM D2997 29206A, Military Specification: “Pipe and Pipe Fittings,
“Standard Specification for Centrifugally Cast ` Glass Fiber Reinforced Plastic for Liquid Petroleum
‘Fiberglass’ (Glass-Fiber-Reinforced Thermosetting- Lines."
Resin) Pipe"
Designation Codes are available in product bulletins.


SE C T I O N 6 . S P E C IF IC A T ION S and APPROVALS

When ordering, specify NSF.
NSF International
(National Sanitation Foundation)
ANSI/NSF Standard No. 14 (Plastic Piping Components (1) Piping greater than 14" diameter using NSF Listed
resin system.
and Related Materials) Listing for conveying potable wa-
ter:
2"-24" RED THREAD II Pipe & Fittings (Performance Underwriters Laboratories Inc. (UL) and Underwriters’
Standard ASTM D2996, RTRP-11AF). Laboratories of Canada (ULC)
1"-24" GREEN THREAD Pipe & Fittings RED THREAD II pipe and compatible primary fittings,
(Performance Standard ASTM D2996, RTRP-11FF). along with secondary containment pipe and fittings, and
adhesives are listed for use in conveying petroleum prod-
ANSI/NSF Standard No. 61 (Drinking Water System ucts, alcohols, and alcohol-gasoline mixtures including
Components—Health Effects) Listing: Note: Standard ethanol, methanol and MTBE underground (UL). The
No. 61 was developed by a consortium and with support primary pipe sizes are 2", 3" and 4"; the secondary con-
from the U.S. Environmental Protection Agency under tainment pipe and fittings sizes are 3" and 4".
cooperative agreement No. CR-812144:
RED THREAD II Pipe These products are listed for use in conveying petroleum
GREEN THREAD Pipe products, gasoline mixtures and up to 100% ethanol un-
RED THREAD II Fittings derground (ULC).
GREEN THREAD Fittings
8000 Series (Epoxy Adhesive)

F-CHEM Pipe (1)

F-CHEM Fittings(1)

TABLE 6.1 Table for Use in Classifying Fiberglass Flanges to ASTM D4024
Pressure
Rating Property
Type Grade Class Desig- Desig-
nation* nation

Filament Wound (FW)................................................................. 1
Compression Molded.................................................................. 2
Resin-Transfer Molded................................................................ 3
Centrifugally Cast........................................................................ 4
Epoxy Resin.................................................................................................... 1
Polyester Resin............................................................................................... 2
Furan Resin..................................................................................................... 3
Integrally-Molded (mfg. on pipe/fitting)...............................................................................1
Taper to Taper Adhesive Joint...........................................................................................2
Straight to Taper Adhesive Joint........................................................................................3
Straight Adhesive Joint. .....................................................................................................4
.
*Gauge Pressure (psig) 50.............................................................................. A
(Flanges must withstand a pressure 100.............................................................................. B
of 4 times the rating without damage 150.............................................................................. C
to the flange) 200.............................................................................. D
250.............................................................................. E
300.............................................................................. F
400..............................................................................G
500.............................................................................. H
PROPERTY 0 1 2 3 4 5 6 7 8
Burst Pressure (psig) (unspecified) 200 400 600 800 1000 1200 1600 2000
Sealing Test Pressure (psig) 75 150 225 300 375 450 600 750
Bolt Torque Limit (ft.•lbs.) 20 30 50 75 100 125 150 200


TABLE 6.2 Classifying Fiberglass Pipe ASTM D2310 ASTM D2996 ASTM D2997
Hoop Short Longit. Tensile Stiffness Short Longit. Tensile Pipe
Stress Test-End Term Tensile Modulus Factor @ Term Tensile Modulus Stiffness
Type Grade Class HDB Closures Burst Strength x 106 5% Defl Burst Strength x 106 5% Defl
D2992 D2992 D1599 D2105 D2105 D2412 D1599 D2105 D2105 D2412

Filament Wound (FW)................................................................. 1
Centrifugally Cast (CC)............................................................... 2

Glass Fiber Reinforced Epoxy Resin.............................................................. 1
Glass Fiber Reinforced Polyester Resin......................................................... 2
Glass Fiber Reinforced Phenolic Resin. ......................................................... 3
.
Glass Fiber Reinforced Furan Resin............................................................... 7

No Liner..............................................................................................................................A
Polyester Resin Liner (Non-Reinforced). ...........................................................................B
.
.
Epoxy Resin Liner (Non-Reinforced). ................................................................................C
Phenolic Resin Liner (Non-Reinforced)..............................................................................D
Polyester Resin Liner (Reinforced)....................................................................................E
Epoxy Resin Liner (Reinforced).........................................................................................F

Engineering & Piping Design Guide
Phenolic Resin Liner (Reinforced). ................................................................................... G
.
Thermoplastic Resin Liner (Specify)..................................................................................H
Furan Resin Liner (Reinforced).......................................................................................... I

Cyclic Values 2500.............................................................................. A
(Determined by D2992 Procedure A) 3150.............................................................................. B
4000.............................................................................. C
5000.............................................................................. D
6300.............................................................................. E
8000.............................................................................. F
10000..............................................................................G
12500.............................................................................. H
Static Values 5000..............................................................................Q
(Determined by D2992 Procedure B) 6300.............................................................................. R
8000.............................................................................. S
10000.............................................................................. T
12500.............................................................................. U
16000..............................................................................W
20000.............................................................................. X
25000.............................................................................. Y
31500.............................................................................. Z

Free End. ................................................................................................................................................................ 1
.
Restrained End. ...................................................................................................................................................... 2
.
Number in Last Four Positions............................. 0.................................................................................................. (Unspecified)
.............................................................................1.................................................................................................. 10000 8000 1 40 4000 2000 0.6 9
.............................................................................2.................................................................................................. 30000 15000 2 200 12000 8000 1.3 18
.............................................................................3.................................................................................................. 40000 25000 3 1000 22000 16000 1.5 36
.............................................................................4.................................................................................................. 50000 35000 4 1500 30000 22000 1.9 72
.............................................................................5.................................................................................................. 60000 45000 5 2000 40000 30000 2.5 144
.............................................................................6.................................................................................................. 70000 55000 6 2500 50000 40000 3.0 288
Examples:
2"-8" GREEN THREAD Pipe RTRP 11FF1-3112 FW Epoxy Epoxy-Re 8000 Free End 40000 10300 1.8 200
10"-12" CL-2030 RTRP-22BS-4444 CC Polyester Poly-Re 8000 - 30000 22000 2.1 73

26
S ECTION 6. SPECIFICATIONS and APPR OVALS

AP PE N D I C E S

APPENDIX A

USEFUL FORMULAS
Where: A = Area; A1 = Surface area of solids; V = Volume; C = Circumference

C

B
W D
A
R
L Ellipse
Rectangle A=p A.B
Circle
A = W.L A = p . R2 C = 2p . A+B
C = p .D 2
R=D/2
D=2 .R

L

α
R
R
H
Sector of Circle
L p . R2 . a Sphere
A= 360 .
Parallelogram A = 4 . p R2
A = H.L p . . 4 .p. 3
L = 180 R a V= 3 R
180L
a=
.
p R
180 . L
R= p.a

L1

S H
H
H

W R L2
Triangle Trapezoid
1 Cone L1 + L2
A= W.H
2 A = p. R. (S + R) A=H
2
V=
p . R2 . H
180

A
B R

W H
H
L
H

B
A
Elliptical Tanks
Rectanglular Solid Cylinder
A = 2 (W . L + L . H + H . W) A = 2 . p . R . (H + R)
A2 + B2 .
V=W.L.H area = 2 . p . A B + H
2 V = p . H . R2
V=p . A .B . H

For Above Containers:
V
Capacity in gallons = when V is in cubic inches Capacity in gallons = 7.48 x V when V is in cubic feet
231


APPEN D IC ES

Support Spans

“Three Moment Equation" for a uniformly loaded continuous beam.

a b c

Where:
Ma = Internal moment at support A, in-lb(N-m)
Mb = Internal moment at support B, in-lb(N-m)
Mc = Internal moment at support C, in-lb(N-m)
L1 = Span length between A & B, in(m)
L2 = Span length between B & C, in(m)
I1 = Area moment of inertia of span 1, in4(m4)
I2 = Area moment of inertia of span 2, in4(m4)
W1 = Uniformly distributed load on span 1, lb/in(N/m)
W2 = Uniformly distributed load on span 2, lb/in(N/m)
E = Pipe beam bending modulus of elasticity, lb/in2(N/m2)

Water Hammer

Talbot Equation for calculating the surge pressure due to an instantaneous change in flow velocity.

Where:
P= Pressure surge, lb/in2 (N/m2)
r= Mass density, lb/in3 (kg/m3)
En = Volume modulus compressibility of fluid, lb/in2 (N/m2)
E= Hoop modulus of elasticity of pipe wall, lb/in2 (N/m2)
t= Pipe wall thickness, in (m)
D= Pipe inner diameter, in (m)
dV= Change in velocity, ft/sec (m/sec)


AP PE N D I C E S

Geometric R e l a tionships for Minimum B ending R a dius

M inimum B ending R a dius La y out


APPENDIX B APPEND IC ES
Table A.1 Water Pressure to Feet of Head

Table A.3 Dry Saturated Steam Pressure
2.31 100 230.90
ABS Press., Temp ABS Press., Temp
2 4.62 110 253.98 Lbs./Sq. In. °F Lbs./Sq. In. °F
3 6.93 120 277.07 0.491 79.03 30 250.33
4 9.24 130 300.16 0.736 91.72 35 259.28
0.982 101.14 40 267.25
5 11.54 140 323.25
1.227 108.71 45 274.44
6 13.85 150 346.34 1.473 115.06 50 281.01
7 16.16 160 369.43 1.964 125.43 55 287.07
8 18.47 170 392.52 2.455 133.76 60 292.71
9 20.78 180 415.61 5 162.24 65 297.97
10 193.21 70 302.92
10 23.09 200 461.78
14.696 212.00 75 307.60
15 34.63 250 577.24 15 213.03 80 312.03
20 46.18 300 692.69 16 216.32 85 316.25
25 57.72 350 808.13 18 222.41 90 320.27
30 69.27 400 922.58 20 227.96 100 327.81
25 240.07 110 334.77
40 92.36 500 1154.48
50 115.45 600 1385.39
60 138.54 700 1616.30 Table A.4 Specific Gravity of Gases
(At 60°F and 29.92 Hg)
70 161.63 800 1847.20
80 184.72 900 2078.10 Dry Air (1cu. ft. at 60° F. and 29.92" Hg. weighs
90 207.81 1000 2309.00 .07638 pound).................................................................. 1.000
Note: One pound of pressure per square inch of water equals 2.309 feet of Acetylene . ..........................C2H2 ..................................... 0.91
water at 62° Fahrenheit. Therefore, to find the feet head of water for any pres- Ethane.................................C2H6 ......................................1.05
sure not given in the table above, multiply the pressure pounds per square
inch by 2.309. Methane.............................. CH4 ................................... 0.554
Ammonia............................. NH3 ................................... 0.596
Table A.2 Feet of Head of Water to psi Carbon-dioxide ................... CO2 ......................................1.53
Carbon-monoxide .................CO ......................................0.967
Butane ..............................C4H10 ................................... 2.067
Butene................................ C4H8 .....................................1.93
Chlorine ................................Cl2 ......................................2.486
.43 100 43.31
Helium .................................. He . ................................... 0.138
2 .87 110 47.64 Hydrogen .............................. H2 . ................................. 0.0696
Nitrogen................................. N2 . ................................. 0.9718
3 1.30 120 51.97 Oxygen ................................. O2 ....................................1.1053
4 1.73 130 56.30
5 2.17 140 60.63
Table A.5 Specific Gravity of Liquids
6 2.60 150 64.96
Temp
7 3.03 160 69.29
Liquid ° F Specific Gravity
8 3.46 170 73.63
Water (1cu. ft. weighs 62.41 lb.) 50 1.00
9 3.90 180 77.96
Brine (Sodium Chloride 25%) 32 1.20
10 4.33 200 86.62 Pennsylvania Crude Oil 80 0.85
15 6.50 250 108.27 Fuel Oil No. 1 and 2 85 0.95
20 8.66 300 129.93 Gasoline 80 0.74
Kerosene 85 0.82
25 10.83 350 151.58
Lubricating Oil SAE 10-20-30 115 0.94
30 12.99 400 173.24
40 17.32 500 216.55
50 21.65 600 259.85 Table A.6 Weight of Water
60 25.99 700 303.16
1 cu. ft. at 50° F . . . . . . . . . . . . . . . . . weighs 62.41 lb.
70 30.32 800 346.47
1 gal. at 50° F . . . . . . . . . . . . . . . . . . weighs 8.34 lb.
80 34.65 900 389.78 1 cu. ft. of ice . . . . . . . . . . . . . . . . . . weighs 57.2 lb.
90 38.98 1000 433.00 1 cu. ft. at 39.2° F . . . . . . . . . . . . . . . weighs 62.43 lb.
Note: One foot of water at 62° Fahrenheit equals .433 pound pressure per Water is at its greatest density at 39.2° F
square inch. To find the pressure per square inch for any feet head not given
in the table above, multiply the feet head by .433.


AP PE N D I C E S

Table A.7 Conversion Factors

Pressure Power
1 in. of mercury = 345.34 kilograms per sq. meter 1 Btu per hr. = 0.293 watt
= 0.0345 kilograms per sq. centimeter = 12.96 ft. lb. per min.
= 0.0334 bar = 0.00039 hp
= 0.491 lb. per sq. in. 1 ton refrigeration
1 lb. per sq. in. = 2.036 in. head of mercury (U.S.) = 288,000 Btu per 24 hr.
= 2.309 ft. head of water = 12,000 Btu per hr.
= 0.0703 kilogram per sq. centimeter = 200 Btu per min.
= 0.0690 bar = 83.33 lb. ice melted per hr. from
= 6894.76 pascals and at 32° F.
1 pascal = 1.0 newton per sq. meter = 2000 lb. ice melted per 24 hr.
= 9.8692 x 10-6 atmospheres from and at 32° F.
= 1.4504 x 10-4 lbs. per sq. in. 1 hp = 550 ft. lb. per sec.
= 4.0148 x 10-3 in. head of water = 746 watt
= 7.5001 x 10-4 cm. head of mercury = 2545 Btu per hr.
= 1.0200 x 10-5 kilogram per sq. meter 1 boiler hp = 33,480 Btu per hr.
= 1.0 x 10-5 bar = 34.5 lb. water evap. per hr. from
1 atmosphere = 101,325 pascals and at 212° F.
= 1,013 milibars = 9.8 kw.
= 14.696 lbs. per sq. in. 1 kw. = 3413 Btu per hr.

Temperature Mass
° C. = (° F.-32) x 5/9 1 lb. (avoir.) = 16 oz. (avoir.)
Weight of Liquid = 7000 grain
1 gal. (U.S.) = 8.34 lb. x sp. gr. 1 ton (short) = 2000 lb.
1 cu. ft. = 62.4 lb. x sp. gr. 1 ton (long) = 2240 lb.
1 lb. = 0.12 U.S. gal. ÷ sp. gr.
= 0.016 cu. ft. ÷ sp. gr.

Volume
1 gal. (U.S.) = 128 fl. oz. (U.S.)
Flow = 231 cu. in.
1 gpm = 0.134 cu. ft. per min. = 0.833 gal. (Brit.)
= 500 lb. per hr. x sp. gr. 1 cu. ft. = 7.48 gal. (U.S.)
500 lb. per hr. = 1 gpm ÷ sp. gr.
1 cu. ft. per min.(cfm) = 448.8 gal. per hr. (gph)

Work
1 Btu (mean) = 778 ft. lb.
= 0.293 watt hr.
= 1/180 of heat required to change
temp of 1 lb. water from 32° F. to
212° F.
1 hp-hr = 2545 Btu (mean)
= 0.746 kwhr
1 kwhr = 3413 Btu (mean)
= 1.34 hp-hr.


NOT ES


E N G I N EE R IN G & P IP IN G D E S IGN GUIDE

ISO 9001
LITTLE ROCK, AR
SAND SPRINGS, OK
SUZHOU, CHINA
FIBER GLASS SYSTEMS

2700 West 65th Street • Little Rock, AR 72209
(501) 568-4010 • Fax: (501) 568-4465

P.O. Box 968 • 25 South Main • Sand Springs, OK 74063
(918) 245-6651 • Fax: (918) 245-7566 or Fax: (800) 365-7473

http://www.smithfibercast.com

® Trademarks of Varco I/P, Inc. PRINTED IN USA, 5M,1007
© 2005, National Oilwell Varco

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