Piping Hydraulics Fluid Flow Selection, Sizing and Troubleshooting
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This document provides guidelines for piping hydraulics, fluid flow, line sizing, and material selection. It covers topics such as general fluid flow theory, flow characteristics in pipes, line sizing methods for both incompressible and compressible fluids, pump suction piping design, and material selection for piping. The document includes case studies and examples to demonstrate how to apply the theoretical concepts. It aims to assist engineers in performing preliminary piping designs and specifications.
Piping Hydraulics Fluid Flow Selection, Sizing and Troubleshooting
- 1. KLM Technology Group Practical Engineering Guidelines for Processing Plant Solutions ENGINEERING SOLUTIONS www.klmtechgroup.com Page : 1 of 64 Rev: 05 Rev 01 Jan 2007 Rev 02 May 2012 Rev 03 Sept 2012 Rev 04 Nov 2013 Rev 05 Jan 2018 KLM Technology Group P. O. Box 281 Bandar Johor Bahru, 80000 Johor Bahru, Johor, West Malaysia Kolmetz Handbook of Process Equipment Design Piping Hydraulics Fluid Flow Line Sizing and Material Selection (ENGINEERING DESIGN GUIDELINES) Co Author Rev 01 Ling Ai Li Rev 02 K Kolmetz Rev 03 Aprilia Jaya Rev 04 Aprilia Jaya Rev 05 Aprilia Jaya Editor / Author Karl Kolmetz TABLE OF CONTENT INTRODUCTION Scope 5 General Design Consideration 6 DEFINITIONS 9 NOMENCLATURE 11 THEORY OF THE DESIGN A) General Fluid Flow Theory 13 I) Physical Properties of Fluids 13 Viscosity 13 Density, Specific Volume and Specify Gravity 13 Mean Velocity 14
- 2. KLM Technology Group Practical Engineering Guidelines for Processing Plant Solutions www.klmtechgroup.com Kolmetz Handbook of Process Equipment Design Piping Hydraulics Fluid Flow Line Sizing and Material Selection (ENGINEERING DESIGN GUIDELINES) Page 2 of 64 Rev: 05 January 2018 These design guideline are believed to be as accurate as possible, but are very general and not for specific design cases. They were designed for engineers to do preliminary designs and process specification sheets. The final design must always be guaranteed for the service selected by the manufacturing vendor, but these guidelines will greatly reduce the amount of up front engineering hours that are required to develop the final design. The guidelines are a training tool for young engineers or a resource for engineers with experience. This document is entrusted to the recipient personally, but the copyright remains with us. It must not be copied, reproduced or in any way communicated or made accessible to third parties without our written consent. II) Flow Characteristic in Pipe 15 Reynolds Number 15 Fluid Flow Equations for the Friction Loss/Pressure Drop in Pipe 16 Straight Line Pressure Drop 19 Effect of Valve, Fitting on Pressure Drop 20 Enlargements and Contraction Pipe Line Pressure Drops Calculation 23 Nozzles and Orifices 24 Water Hammer 24 B) Piping Fluid Flow Material Selection 24 C) Line Sizing 28 I) Liquid Flow (In-Compressible Flow) 29 II) Gas Flow (Compressible Flow) 30 D) Pump Suction Piping 35 APPLICATION Example Case 1: In-Compressible flow with Water 43 Example Case 2: In-Compressible flow with HC 46 Example Case 3: Compressible flow with Steam 49 Example Case 4: Compressible flow with Natural Gas 52 Example Case 5: Pump Suction 55
- 3. KLM Technology Group Practical Engineering Guidelines for Processing Plant Solutions www.klmtechgroup.com Kolmetz Handbook of Process Equipment Design Piping Hydraulics Fluid Flow Line Sizing and Material Selection (ENGINEERING DESIGN GUIDELINES) Page 3 of 64 Rev: 05 January 2018 These design guideline are believed to be as accurate as possible, but are very general and not for specific design cases. They were designed for engineers to do preliminary designs and process specification sheets. The final design must always be guaranteed for the service selected by the manufacturing vendor, but these guidelines will greatly reduce the amount of up front engineering hours that are required to develop the final design. The guidelines are a training tool for young engineers or a resource for engineers with experience. This document is entrusted to the recipient personally, but the copyright remains with us. It must not be copied, reproduced or in any way communicated or made accessible to third parties without our written consent. REFERENCES 58 LIST OF TABLE Table 1: General Pipe Material Roughness 19 Table 2a: Example of the equivalent lengths for various kinds of fittings 21 Table 2b: Friction factor for the commercial steel pipe 21 Table 3: Guideline for the Piping Fitting and Pipe Material Selection 29 Table 4: Pipe velocities and allowable pressure drops for various fluids 31 Table 5: Optimum velocity for various fluid densities 31 Table 6: Reasonable Velocities for flow of water/fluid with almost same density through pipe 33 Table 7: Reasonable Velocities for flow of steam through pipe 37 Table 8: Vapor pressure (VP) versus temperature for water 40
- 4. KLM Technology Group Practical Engineering Guidelines for Processing Plant Solutions www.klmtechgroup.com Kolmetz Handbook of Process Equipment Design Piping Hydraulics Fluid Flow Line Sizing and Material Selection (ENGINEERING DESIGN GUIDELINES) Page 4 of 64 Rev: 05 January 2018 These design guideline are believed to be as accurate as possible, but are very general and not for specific design cases. They were designed for engineers to do preliminary designs and process specification sheets. The final design must always be guaranteed for the service selected by the manufacturing vendor, but these guidelines will greatly reduce the amount of up front engineering hours that are required to develop the final design. The guidelines are a training tool for young engineers or a resource for engineers with experience. This document is entrusted to the recipient personally, but the copyright remains with us. It must not be copied, reproduced or in any way communicated or made accessible to third parties without our written consent. INTRODUCTION Scope The understanding of how gasses and fluids flow in equipment is the foundation of equipment design. All of the other Engineering Design Guidelines are based on these fundamentals; therefore it is critical that the principles of fluid flow are understood before designing equipment. The principles are not complex, but neither are they simple due to the interdependence of pressure drop and friction. This design guideline covers the basic elements in the field of Piping Fluid Flow Material Selection and Line Sizing in sufficient detail to design a pipeline and / or other piping classes. This design guideline includes single phase liquid flow, single phase gas flow for hydrocarbon, water, steam and natural gases. Two phase flow is covered in a separate guideline. Proper pipe sizing is determined by the length of the pipe and the allowable pressure drop in the line. The allowable pressure drop may be influenced by factors, including process requirements, economics, safety, and noise or vibration limitations. This guideline also covers other piping related equipment, such as valve, fittings and orifices. Pressure drop calculations in these fitting are discussed in detail to help the design of piping systems. Fluid phases can be considered as pure liquid or pure gas phases. In this guideline, these differences phases were discussed in detail for the engineering design for the laminar and turbulence flow and for various substances of fluids, for example, water, steam and hydrocarbon. A second guideline discusses mixed phase fundamentals. The theory section covers the selection method of the piping material based on their application and engineering calculations for the sizing of the piping. In the application
- 5. KLM Technology Group Practical Engineering Guidelines for Processing Plant Solutions www.klmtechgroup.com Kolmetz Handbook of Process Equipment Design Piping Hydraulics Fluid Flow Line Sizing and Material Selection (ENGINEERING DESIGN GUIDELINES) Page 5 of 64 Rev: 05 January 2018 These design guideline are believed to be as accurate as possible, but are very general and not for specific design cases. They were designed for engineers to do preliminary designs and process specification sheets. The final design must always be guaranteed for the service selected by the manufacturing vendor, but these guidelines will greatly reduce the amount of up front engineering hours that are required to develop the final design. The guidelines are a training tool for young engineers or a resource for engineers with experience. This document is entrusted to the recipient personally, but the copyright remains with us. It must not be copied, reproduced or in any way communicated or made accessible to third parties without our written consent. section of this guideline, four case studies are shown and discussed in detail, highlighting the way to apply the theory for the calculation. Fundamental theories, such as Bernoulli’s theory, is used as the basic of calculations because it is applicable for various conditions. The case studies will assist the engineer develop typical selection and sizing for the piping based on their own plant system. Example Calculation Spreadsheets are included in this guideline. The Example Calculation Spreadsheets are based on case studies in the application section to make them easier to understand.
- 6. KLM Technology Group Practical Engineering Guidelines for Processing Plant Solutions www.klmtechgroup.com Kolmetz Handbook of Process Equipment Design Piping Hydraulics Fluid Flow Line Sizing and Material Selection (ENGINEERING DESIGN GUIDELINES) Page 6 of 64 Rev: 05 January 2018 These design guideline are believed to be as accurate as possible, but are very general and not for specific design cases. They were designed for engineers to do preliminary designs and process specification sheets. The final design must always be guaranteed for the service selected by the manufacturing vendor, but these guidelines will greatly reduce the amount of up front engineering hours that are required to develop the final design. The guidelines are a training tool for young engineers or a resource for engineers with experience. This document is entrusted to the recipient personally, but the copyright remains with us. It must not be copied, reproduced or in any way communicated or made accessible to third parties without our written consent. General Design Consideration In designing the piping fluid flow there are many factors have to be considered for the suitability of the material selection for the application codes and standards, environmental requirements, safety, performance of the requirements, and the economics of the design and other parameters which may constrain the work. They should be included engineering calculations for the piping system design. Combined with the piping design criteria, calculations define the process flow rates, system pressure and temperature, pipe wall thickness, and stress and pipe support requirements. The service conditions should be the consideration as well because the piping system is designed to accommodate all combinations of loading situations such as pressure changes, temperature changes, thermal expansion and contraction and other forces or moments that may occur simultaneously and they are used to set the stress limit of the design. Design code and the standards are reviewed for the project of the design for the safety purposes and the verification of the applicability. In this design guideline generally follows the codes and the standards of the American Society of Mechanical Engineers (ASME) Code for Pressure Piping, B31. ASME B31 includes the minimum design requirements for various pressure piping applications.(4) Normal environmental factors that have the potential for damage due to corrosion must be addressed in the design of process piping. Physical damage may also occur due to credible operational and natural phenomena, such as fires, earthquakes, winds, snow or ice loading, and subsidence. Two instances of temperature changes must be considered as a minimum.
- 7. KLM Technology Group Practical Engineering Guidelines for Processing Plant Solutions www.klmtechgroup.com Kolmetz Handbook of Process Equipment Design Piping Hydraulics Fluid Flow Line Sizing and Material Selection (ENGINEERING DESIGN GUIDELINES) Page 7 of 64 Rev: 05 January 2018 These design guideline are believed to be as accurate as possible, but are very general and not for specific design cases. They were designed for engineers to do preliminary designs and process specification sheets. The final design must always be guaranteed for the service selected by the manufacturing vendor, but these guidelines will greatly reduce the amount of up front engineering hours that are required to develop the final design. The guidelines are a training tool for young engineers or a resource for engineers with experience. This document is entrusted to the recipient personally, but the copyright remains with us. It must not be copied, reproduced or in any way communicated or made accessible to third parties without our written consent. First, there are daily and seasonal changes. Second, thermal expansion where elevated liquid temperatures are used must be accommodated. Compensation for the resulting expansions contractions are made in both the piping system and support systems. Internal wear and erosion also pose unseen hazards that can result in system failures. Most failures of fluid process systems occur at or within interconnect points the piping, flanges, valves, fittings, etc. It is, therefore, vital to select interconnecting equipment and materials that are compatible with each other and the expected environment. Materials selection is an optimization process, and the material selected for an application must be chosen for the sum of its properties. That is, the selected material may not rank first in each evaluation category; it should, however, be the best overall choice. Considerations include cost and availability. Key evaluation factors are strength, ductility, toughness, and corrosion resistance. Piping material is selected by optimizing the basis of design. The remaining materials are evaluated for advantages and disadvantages such as capital, fabrication and installation costs; support system complexity; compatibility to handle thermal cycling; and catholic protection requirements. The highest ranked material of construction is then selected. The design proceeds with pipe sizing, pressure integrity calculations and stress analyses. If the selected piping material does not meet those requirements, then second ranked material is used to sizing, pressure integrity calculation and stress analyses are repeated. For the pressure drop calculation: the primary requirement of the design is to find an inside diameter with system design flow rates and pressure drops. The design flow rates are based on system demands that are normally established in the process design phase of a project. This will involves trial and error procedure to find the suitable inside diameter.
- 8. KLM Technology Group Practical Engineering Guidelines for Processing Plant Solutions www.klmtechgroup.com Kolmetz Handbook of Process Equipment Design Piping Hydraulics Fluid Flow Line Sizing and Material Selection (ENGINEERING DESIGN GUIDELINES) Page 8 of 64 Rev: 05 January 2018 These design guideline are believed to be as accurate as possible, but are very general and not for specific design cases. They were designed for engineers to do preliminary designs and process specification sheets. The final design must always be guaranteed for the service selected by the manufacturing vendor, but these guidelines will greatly reduce the amount of up front engineering hours that are required to develop the final design. The guidelines are a training tool for young engineers or a resource for engineers with experience. This document is entrusted to the recipient personally, but the copyright remains with us. It must not be copied, reproduced or in any way communicated or made accessible to third parties without our written consent. Basically service conditions must be reviewed to determine operational requirements such as recommended fluid velocity for the application and liquid characteristics such as viscosity, temperature, suspended solids concentration, solids density and settling velocity, abrasiveness and corrosively. This information is useful to determine the minimum internal diameter of the pipe for the whole system network. Normal liquid service applications, the acceptable velocity in pipes is 2.1 ± 0.9 m/s (7 ± 3 ft/s) with a maximum velocity limited to 2.1 m/s (7 ft/s) at piping discharge points. This velocity range is considered reasonable for normal applications.(4) Pressure drops throughout the piping network are designed to provide an optimum balance between the installed cost of the piping system and operating costs of the system pumps. Primary factors that will impact these costs and system operating performance are internal pipe diameter (and the resulting fluid velocity), materials of construction and pipe routing. Pressure drop, or head loss, is caused by friction between the pipe wall and the fluid, and by minor losses such as flow obstructions, changes in direction, changes in flow area, etc. Fluid head loss is added to elevation changes to determine pump requirements. A common method for calculating pressure drop is the Darcy-Weisbach equation. Normally for the line sizing the following rules should be follow 1) Calculate the Pressure drop with expressed in the term “psi/100 ft of pipe”. 2) Select the suitable Velocity which expressed in ft/sec; there is standard for general liquid flow the range of the velocity should be in the suitable range for the basic design.
- 9. KLM Technology Group Practical Engineering Guidelines for Processing Plant Solutions www.klmtechgroup.com Kolmetz Handbook of Process Equipment Design Piping Hydraulics Fluid Flow Line Sizing and Material Selection (ENGINEERING DESIGN GUIDELINES) Page 9 of 64 Rev: 05 January 2018 These design guideline are believed to be as accurate as possible, but are very general and not for specific design cases. They were designed for engineers to do preliminary designs and process specification sheets. The final design must always be guaranteed for the service selected by the manufacturing vendor, but these guidelines will greatly reduce the amount of up front engineering hours that are required to develop the final design. The guidelines are a training tool for young engineers or a resource for engineers with experience. This document is entrusted to the recipient personally, but the copyright remains with us. It must not be copied, reproduced or in any way communicated or made accessible to third parties without our written consent. 3) Calculate the Reynolds number to determine the fluid flow. Reynolds number is a factor of pipe diameter, flow rate, density, and viscosity of the liquid; allows analysis of flow characteristics (slug, laminar, transition, turbulent); sanitary systems always require full turbulence (Reynolds number > 10,000) 4) Determine the suitable of pipe diameter- the inside pipe or tube diameter is used in the several equations to determine the pressure drops, Reynolds number, velocity and etc. 5) Determine the roughness of pipe, the more rough the pipe, the larger the friction factor; the larger the friction factor, the more pressure drop. 6) Incompressible flow- liquids; actual pressure is not a factor in pressure drop calculation. 7) Compressible flow- gases and vapors; actual pressure is a direct factor in pressure drop calculation. Liquids (Incompressible Flow):Size longer lines for less pressure drop than shorter lines. Most water-like liquids, long lines should be sized for 0.5 to 1.0 psi/100 ft; short lines should be sized for 1.0 to 2.0 psi/100 ft; but there are no hard and fast rules. For liquids with viscosities 10 cp or less consider just like water; above 10 cp, check Reynolds number to see what equations to use for pressure drop calculation. Careful with sizing lines in the fractional line size range; It may cost more to install ¾” pipe and smaller than 1” pipe due to support requirements. Usually do not save on header sizing to allow for future increase in capacity without changing out piping. Pipeline holdup of process liquids may be a factor; smaller pipe may be desired to limit holdup even though pressure drop goes up.
- 10. KLM Technology Group Practical Engineering Guidelines for Processing Plant Solutions www.klmtechgroup.com Kolmetz Handbook of Process Equipment Design Piping Hydraulics Fluid Flow Line Sizing and Material Selection (ENGINEERING DESIGN GUIDELINES) Page 10 of 64 Rev: 05 January 2018 These design guideline are believed to be as accurate as possible, but are very general and not for specific design cases. They were designed for engineers to do preliminary designs and process specification sheets. The final design must always be guaranteed for the service selected by the manufacturing vendor, but these guidelines will greatly reduce the amount of up front engineering hours that are required to develop the final design. The guidelines are a training tool for young engineers or a resource for engineers with experience. This document is entrusted to the recipient personally, but the copyright remains with us. It must not be copied, reproduced or in any way communicated or made accessible to third parties without our written consent. Gases and Vapors (Compressible Flow): Supply pressure is a major factor in line sizing calculations; also, overall pressure drop by means of typical calculation methods should not exceed 10% of the supply pressure, otherwise, alternative calculation methods must be used. Typically, consider all gases and vapors (including saturated steam) to behave gases in order to calculate vapor densities (PV = nRT). DEFINITIONS Compressible Fluid - Molecules in a fluid to be compacted and the density is varies. Energy is exchanged not only among the kinetic energy and the potential energies due to gravity and pressure, but also with the internal energy (7). Darcy Friction Factor, f -This factor is a function of Reynolds Number and relative pipe wall roughness, ε/d. For a given class of pipe material, the roughness is relatively independent of the pipe diameter, so that in a plot of f vs. Re, d often replaces ε/d as a parameter. In-Compressible Fluid- An incompressible flow is one in which the density of the fluid is constant or nearly constant. Liquid flows are normally treated as incompressible (6). Molecules in a fluid to be cannot be compacted. Generally the flow energy is converted to friction, kinetic and potential energy if available and not the internal energy. Laminar Flow - Laminar flow occurs when adjacent layers of fluid move relative to each other in smooth streamlines, without macroscopic mixing. In laminar flow, viscous shear, which is caused by molecular momentum exchange between fluid layers, is the predominant influence in establishing the fluid flow. This flow type occurs in pipes when Re < 2,100. Newtonian Fluids - A fluid characterized by a linear relationship between shear rate (rate of angular deformation) and shear stress.
- 11. KLM Technology Group Practical Engineering Guidelines for Processing Plant Solutions www.klmtechgroup.com Kolmetz Handbook of Process Equipment Design Piping Hydraulics Fluid Flow Line Sizing and Material Selection (ENGINEERING DESIGN GUIDELINES) Page 11 of 64 Rev: 05 January 2018 These design guideline are believed to be as accurate as possible, but are very general and not for specific design cases. They were designed for engineers to do preliminary designs and process specification sheets. The final design must always be guaranteed for the service selected by the manufacturing vendor, but these guidelines will greatly reduce the amount of up front engineering hours that are required to develop the final design. The guidelines are a training tool for young engineers or a resource for engineers with experience. This document is entrusted to the recipient personally, but the copyright remains with us. It must not be copied, reproduced or in any way communicated or made accessible to third parties without our written consent. Non-Newtonian Liquids - Fluids may be broadly classified by their ability to retain the memory of a past deformation (which is usually reflected in a time dependence of the material properties). Fluids that display memory effects usually exhibit elasticity.(8)Fluids in which viscosity depends on shear rate and/or time. Examples are some slurries, emulsions, and polymer melts and solutions. Relative Roughness - Ratio of absolute pipe wall roughness ε to inside diameter d, in consistent units. Reynolds Number, Re - A dimensionless number which expresses the ratio of inertial to viscous forces in fluid flow Resistance Coefficient, K - Empirical coefficient in the friction loss equation for valves and fittings. It expresses the number of velocity heads lost by friction for the particular valve or fitting. The coefficient is usually a function of the nominal diameter. Shear Rate - The velocity gradient (change in velocity with position). Shear Stress - Force per unit area. Force in direction of flow; area in plane normal to velocity gradient. Sonic Velocity (Choked Flow) - The maximum velocity that a gas or gas-liquid mixture can attain in a conduit at a given upstream pressure (except in certain converging- diverging nozzles), no matter how low the discharge pressure is. For gases this maximum velocity is equal to the speed of sound at the local conditions. Specific gravity - Is a relative measure of weight density. Normally pressure has not significant effect for the weight density of liquid, temperature is only condition must be considered in designating the basis for specific gravity.
- 12. KLM Technology Group Practical Engineering Guidelines for Processing Plant Solutions www.klmtechgroup.com Kolmetz Handbook of Process Equipment Design Piping Hydraulics Fluid Flow Line Sizing and Material Selection (ENGINEERING DESIGN GUIDELINES) Page 12 of 64 Rev: 05 January 2018 These design guideline are believed to be as accurate as possible, but are very general and not for specific design cases. They were designed for engineers to do preliminary designs and process specification sheets. The final design must always be guaranteed for the service selected by the manufacturing vendor, but these guidelines will greatly reduce the amount of up front engineering hours that are required to develop the final design. The guidelines are a training tool for young engineers or a resource for engineers with experience. This document is entrusted to the recipient personally, but the copyright remains with us. It must not be copied, reproduced or in any way communicated or made accessible to third parties without our written consent. Steam Hammer - Steam hammer is excessive pipe vibrations that occur due to the collapse of large vapor bubbles in a cool liquid stream. Transition Flow - Flow regime lying between laminar and turbulent flow. In this regime velocity fluctuations may or may not be present and flow may be intermittently laminar and turbulent. This flow type occurs in pipes when 2,100 < Re < 4,000. Turbulent Flow - Turbulence is characterized by velocity fluctuations that transport momentum across streamlines; there is no simple relationship between shear stress and strain rate in turbulent flow. Instantaneous properties cannot be predicted in a turbulent flow field; only average values can be calculated. For engineering analyses, turbulent flow is handled empirically using curve-fits to velocity profiles and experimentally determinate loss coefficients. This flow type occurs in pipes in industrial situations when Re > 4,000. Under very controlled laboratory situations, laminar flow may persist at Re > 4,000. Viscosity- Defined as the shear stress per unit area at any point in a confined fluid divided by the velocity gradient in the direction perpendicular to the direction of flow, if the ratio is constant with time at a given temperature and pressure for any species, the fluid is called a Newtonian fluid. Water Hammer - Water hammer is the dynamic pressure surge that results from the sudden transformation of the kinetic energy in a flowing fluid into pressure when the flow is suddenly stopped. The sudden closing of a valve can cause a water hammer.
- 13. KLM Technology Group Practical Engineering Guidelines for Processing Plant Solutions www.klmtechgroup.com Kolmetz Handbook of Process Equipment Design Piping Hydraulics Fluid Flow Line Sizing and Material Selection (ENGINEERING DESIGN GUIDELINES) Page 13 of 64 Rev: 05 January 2018 These design guideline are believed to be as accurate as possible, but are very general and not for specific design cases. They were designed for engineers to do preliminary designs and process specification sheets. The final design must always be guaranteed for the service selected by the manufacturing vendor, but these guidelines will greatly reduce the amount of up front engineering hours that are required to develop the final design. The guidelines are a training tool for young engineers or a resource for engineers with experience. This document is entrusted to the recipient personally, but the copyright remains with us. It must not be copied, reproduced or in any way communicated or made accessible to third parties without our written consent. NOMENCLATURE A Radius-sectional area, ft2 (m2) a Sum of mechanical allowances plus corrosion allowance plus erosion allowance, in(mm) C Flow coefficient for the nozzles and orifices c Compressible factor, for perfect gas c =1.0 D Internal diameter of pipe, ft (m) d Internal diameter of pipe, in (mm) d1 Pipe with smaller diameter in enlargements or contractions in pipes d2 Pipe with smaller diameter in enlargements or contractions in pipes de Equivalent hydraulic diameter, in (mm) Do Outside diameter of pipe, in. (mm) E Weld joint efficiency or quality factor from ASME B31.3 f Dancy’s friction factor, dimensionless ft Friction factor for fitting g Acceleration of gravity, ft/s2 (m/s2) – 32.2ft/s2 – 9.8m/s2 GPM Volume flow rate, gpm (m3/hr) ΔH Surge pressure, ft-liq (m-liq) hL Head loss, ft (m) k Ratio of specific heat at constant pressure to specific heat at constant volume = cp/cv K Resistance coefficient, dimensionless K1 Resistance coefficient for enlargement/contraction, dimensionless L Length of pipe, ft (m) Leq Equivalent length, ft (m) Lm Length of pipe, miles (m) M Molecular weight P Pressure drop in pipe, Ibf/in2(kg/cm2) Pi Internal design pressure, psig (kg/cm2 gage) Pwr power, hp (kW) Q Volumetric flow rate, ft3/s (m3/s) q Volumetric flow rate, ft3/hr (m3/hr) Q1 Rate of flow, gal/min (m3/min)
- 14. KLM Technology Group Practical Engineering Guidelines for Processing Plant Solutions www.klmtechgroup.com Kolmetz Handbook of Process Equipment Design Piping Hydraulics Fluid Flow Line Sizing and Material Selection (ENGINEERING DESIGN GUIDELINES) Page 14 of 64 Rev: 05 January 2018 These design guideline are believed to be as accurate as possible, but are very general and not for specific design cases. They were designed for engineers to do preliminary designs and process specification sheets. The final design must always be guaranteed for the service selected by the manufacturing vendor, but these guidelines will greatly reduce the amount of up front engineering hours that are required to develop the final design. The guidelines are a training tool for young engineers or a resource for engineers with experience. This document is entrusted to the recipient personally, but the copyright remains with us. It must not be copied, reproduced or in any way communicated or made accessible to third parties without our written consent. R Individual gas constant, MR =1544 Re Reynolds Number, dimensionless S Specific gravity of a liquid, dimensionless (hydrocarbon in API) Sg Specific gravity of a gas, dimensionless Sm Allowable stress, from ASME B31.3, psi (MPa) T Absolute temperature, R (460+oF) Tv Valve stroking time (s) Te Effective valve stroking time (s) t Pressure design minimum thickness, in. (mm) tm Total minimum wall thickness required for pressure integrity, in. (mm) tnom Wall thickness, in. (mm) V Mean velocity, ft/s (m/s) V Specific volume, ft3/Ibm (m3/kg) 1V Inlet specific volume, ft3/Ib (m3/kg) Vmax The bigger velocity for enlargement / contraction, ft/s (m/s) ΔV Change of linear flow velocity, ft/s (m/s) vs Sonic velocity, ft/s (kg/s) W Mass flow rate, Ibm/hr (kg/hr) w Mass flow rate, Ibm/s (kg/s) Y Expansion factor (dimensionless) z Elevation of pipe, ft (m) Greek letters Weight density of fluid, Ibm/ft3 (kg/m3) e Absolute viscosity, Ibm.s /ft (kg.s/m) Absolute (dynamic) viscosity, cp ε Absolute roughness, in (mm) Angle of convergence or divergence in enlargements or contractions in pipes Differential between two points
- 15. KLM Technology Group Practical Engineering Guidelines for Processing Plant Solutions www.klmtechgroup.com Kolmetz Handbook of Process Equipment Design Piping Hydraulics Fluid Flow Line Sizing and Material Selection (ENGINEERING DESIGN GUIDELINES) Page 15 of 64 Rev: 05 January 2018 These design guideline are believed to be as accurate as possible, but are very general and not for specific design cases. They were designed for engineers to do preliminary designs and process specification sheets. The final design must always be guaranteed for the service selected by the manufacturing vendor, but these guidelines will greatly reduce the amount of up front engineering hours that are required to develop the final design. The guidelines are a training tool for young engineers or a resource for engineers with experience. This document is entrusted to the recipient personally, but the copyright remains with us. It must not be copied, reproduced or in any way communicated or made accessible to third parties without our written consent. THEORY A) General Fluid Flow Theory I) Physical Properties of Fluids Physical properties of fluid are important for any flow problem and the accuracy of the values will affect the flow of fluid in the pipeline. Viscosity A fluid viscosity can be described by its Dynamic viscosity (sometimes called Absolute viscosity), or its Kinematics viscosity. These two expressions of viscosity are not the same, but are linked via the fluid density. Kinematics viscosity = Dynamic viscosity / fluid density Density, Specific Volume and Specify Gravity The weight density or specific weight of a substance is its weight per unit volume. The specific volume V is the reciprocal of the weight density, is expressed in the SI system as the number of cubic meter of space occupied by one kilogram of the substance. The specific gravity of a liquid is the ratio of its weight density at specified temperature to that of water at standard temperature, 60F English Metric S = F60atwaterρ etemperaturspecificatliquidanyρ S = F60atwaterρ etemperaturspecificatliquidanyρ Eq (1a)
- 16. KLM Technology Group Practical Engineering Guidelines for Processing Plant Solutions www.klmtechgroup.com Kolmetz Handbook of Process Equipment Design Piping Hydraulics Fluid Flow Line Sizing and Material Selection (ENGINEERING DESIGN GUIDELINES) Page 16 of 64 Rev: 05 January 2018 These design guideline are believed to be as accurate as possible, but are very general and not for specific design cases. They were designed for engineers to do preliminary designs and process specification sheets. The final design must always be guaranteed for the service selected by the manufacturing vendor, but these guidelines will greatly reduce the amount of up front engineering hours that are required to develop the final design. The guidelines are a training tool for young engineers or a resource for engineers with experience. This document is entrusted to the recipient personally, but the copyright remains with us. It must not be copied, reproduced or in any way communicated or made accessible to third parties without our written consent. For hydrocarbon like oil, the API unit is used. English Metric S (60 F / 60 F) = API.deg5.131 5.141 S (60 F / 60 F) = API.deg5.131 5.141 Eq(1b) Normal water deg. API unit is 10, that mean water S = 1.00 For gas the specific gravity Sg is expressed as English Metric Sg = )air(M )gas(M Sg = )air(M )gas(M Eq (1c) Mean Velocity Mean velocity is the average velocity in flow across the given cross section as determined by the continuity equation for steady state flow. It normally express as ratio of the volumetric flow rate (Q) to sectional area (A) of the pipe. English Metric Mean Velocity, V = A Q V = A Q Eq (2) which, V = mean velocity, ft/s (m/s) Q = volumetric flow rate, ft3/s (m3/s) A = radius-sectional area, ft2 (m2)
- 17. KLM Technology Group Practical Engineering Guidelines for Processing Plant Solutions www.klmtechgroup.com Kolmetz Handbook of Process Equipment Design Piping Hydraulics Fluid Flow Line Sizing and Material Selection (ENGINEERING DESIGN GUIDELINES) Page 17 of 64 Rev: 05 January 2018 These design guideline are believed to be as accurate as possible, but are very general and not for specific design cases. They were designed for engineers to do preliminary designs and process specification sheets. The final design must always be guaranteed for the service selected by the manufacturing vendor, but these guidelines will greatly reduce the amount of up front engineering hours that are required to develop the final design. The guidelines are a training tool for young engineers or a resource for engineers with experience. This document is entrusted to the recipient personally, but the copyright remains with us. It must not be copied, reproduced or in any way communicated or made accessible to third parties without our written consent. Which, Volumetric flow rate, Q, ft3/s (m3/s) in the pipe line is the ratio of the mass flow rate to density of the fluid. English Metric Volumetric flow rate, Q = w Q = w Eq (3) which, w = mass flow rate, Ibm/s (kg/s) = weight density of fluid, Ibm/ft3 (kg/m3) and the Sectional Area in pipe, A, ft2 (m2) formula is expressed as English Metric Sectional area, A = 4 2 D A = 4 2 D Eq (4) Where, D = diameter of pipe, ft (m)
- 18. KLM Technology Group Practical Engineering Guidelines for Processing Plant Solutions www.klmtechgroup.com Kolmetz Handbook of Process Equipment Design Piping Hydraulics Fluid Flow Line Sizing and Material Selection (ENGINEERING DESIGN GUIDELINES) Page 18 of 64 Rev: 05 January 2018 These design guideline are believed to be as accurate as possible, but are very general and not for specific design cases. They were designed for engineers to do preliminary designs and process specification sheets. The final design must always be guaranteed for the service selected by the manufacturing vendor, but these guidelines will greatly reduce the amount of up front engineering hours that are required to develop the final design. The guidelines are a training tool for young engineers or a resource for engineers with experience. This document is entrusted to the recipient personally, but the copyright remains with us. It must not be copied, reproduced or in any way communicated or made accessible to third parties without our written consent. II) Flow Characteristic in Pipe There are three different types of flow in pipe and these determine the pipe sizing. There are laminar flow, between laminar and transition zones flow, and turbulent flow. This is very important for the designer to determine the type of flow of the fluid before proceeding with the calculation. Reynolds Number The Reynolds Number is used to determine the nature of flow in pipe whether is the laminar flow or turbulent flow. Reynolds Number with symbol Re, which depend with pipe diameter (D), the density (ρ) and absolute viscosity (μ) of the flowing fluid and it velocity ( )V of the flow. This number is a dimensionless group with combination of these four variables which expressed as English Metric Re = dμ Q50.6 1 Re = eμ DVρ Eq (5a) which, D = internal diameter of pipe, ft (m) V = mean velocity of flow, ft/s (m/s) = weight density of fluid, Ibm/ft3 (kg/m3) e = absolute viscosity, Ibm /ft.s (kg /m.s) d = internal diameter of pipe, in (mm) Q1 = Mass flow, gal/min (m3/min) = absolute (dynamic) viscosity, cp