Pipe Support & EJ Field Examples & Case Studies

Editor's Notes

• #2: NEXT PAGE: introduction of yourself and Webinar
• #3: Hello everyone, I would like to welcome you to our Webinar on Pipe Support and Expansion Joint Field Examples and Case Studies. The Webinar today is hosted by Piping Technology & Products. I am Jerry Godina and I will be your presenter. Also, if you have a question, please feel free to chat it to us during the presentation in the text box you see to the right of the presentation.
• #4: For those of you who are unfamiliar with PT&P, I want to quickly go over some background information. If you would like to know more, please visit our “About Us” section at pipingtech.com. Our parent company, Piping Technology & Products, Inc., also known as PT&P, is a member of MSS, SPED, and APFA In business since 1975, Piping Technology & Products, Inc. and its wholly owned subsidiaries (US Bellows, Sweco Fab, Pipe Shields, and Anchor Darling) offer a wide range of engineered products and services for various industries and applications. Our product line is extensive… From engineered pipe supports, expansion joints, pre-insulated pipe supports, and miscellaneous fabrication to various engineering and technical services, PT&P has decades of experience providing products and services for all your engineering and construction needs. The focus of today’s Webinar will be about the resolution of conflicts at the site. Foreseen could be accommodated during the design phase and carried through the manufacture OR those seen in operation which warranted retrofit at the site.
• #5: Substantially larger movement (travel) required than available with the standard variable spring Proximity of supports b/w each other and structural steel members did not permit use of constants Solution incorporated custom spring housings / components which could hold 5 and 6 coil arrangement Result was relatively low spring rates which could accommodate 8+ inches of movement while producing relatively small load changes
• #6: Presented with circumstance where load / movement specifications matched standard variable spring, but overall height available was significantly shorter than the minimum obtainable with standard spring Solution: incorporated concept used in “Big Ton” spring design: number of smaller (and shorter) coils used in parallel to increase load capacity while maintaining overall height Example shown used four coil arrangement (nested coils) to mimic performance of substantially larger spring
• #7: Example of big ton concept applied to constant effort support Major design specification which had to be maintained (besides load / travel requirements) was the installed height of 26” Standard design constant had a minimum installed height of 34” and used a single coil with diameter of 23” Custom design was developed which incorporated dual coil / cam / load table combination working in tandem to fit within space allotted
• #8: Standard slide plate construction consists of slide plate material (PTFE, 25% glass filled) chemically bonded to steel backing plate When used in high temperature applications, the glue began to deteriorate at temperatures over 350 degrees Fahrenheit Once the glue strength was compromised, the slide plate became non-functional Case: Limited use of graphite and temperature limits of PTFE, 25% Glass Filled for use in merchant plants Solution: Development of stainless steel encased Marinite to reduce heat gradient & withstand transients PTFE, 25% glass filled material was not protected from high temperatures Graphite was not strong enough to withstand water hammer in this application The Marinite insulator assembly allows the use of PTFE, 25% glass filled, as the sliding surface for lines with high operating temperatures and high dynamic loading - Maximum operating temperature for PTFE ≈ 325F –after which the glue could become dis-bonded - Using soli8d sheet of graphite proved unacceptable because of dynamic loading conditions Bronzphite® can also be used for high temperatures and high loads
• #9: Marinite slide plate consists of two main components: 1.) Structural steel “skeleton” to withstand high load conditions. 2.) Marinite insulation used to isolate high temperature zone from low temperature zone. With the insulation being used, standard slide plate components can be incorporated at the low temperature zone
• #10: Case: It was necessary to increase the lifespan of an expansion joint for a coal-fired power plant. Pressure tests were used to check the six packing seals. This joint is to be installed in a horizontal position in the mid-span of 40" between guided supports. The design conditions are 12 " of movement, 650 ° F, and 50 PSI of internal pressure. http://www.pipingtech.com/news/arc_pw_1994/expjt1994_09.htm
• #11: The solution was to design a self-cleaning slip-type expansion joint. Several special requirements where met by a combination of design features and material specifications including an aluminum bronze bearing sleeve. The inner barrel (which is directly in the vision of the operator) is uniquely plated to be corrosion resistant. This operator is using a load cell to measure the force required to move the joint.
• #12: Problem: Piping Technology & Products, Inc. received an emergency request through the website on Friday at 5:30 pm from a customer. The customer reported that the line anchors had failed, causing one of the 48” expansion joints to squirm.
• #13: Resolution: Friday evening they sent PT&P the drawings and a purchase order for the job. On Saturday, the expansion joint was formed, and air freighted back to the customer on Sunday morning. The pipeline was back in operation on Sunday. PT&P suggested that tie rods be installed to prevent future squirming of the expansion joint.
• #14: Examples of various styles of travel stops (Hydrotest stops) One benefit of performing a survey (walk-down) of entire system is that all support can be reviewed Recommendations / procedures can then be developed to rectify any installation irregularities
• #16: Second benefit of field survey includes determination of adjustment versus replacement criteria Examples shown indicate supports which require only adjustment to be brought back to original operating specifications
• #18: Examples of the necessity of understanding both the installed condition and operating condition of supports Modifications made to the snubber settings during installation did not cause immediate damage During operation, however, the results of those modifications could be seen The snubber in the left picture became fully extended while it’s counterpart in the right picture became fully retracted causing significant stress on the seals which ultimately lead to their failure
• #20: Example of the degree / extent of refurbishment which can be completed at the site Relatively short time frame (2 days) available for repairs mandated that all work be completed in the field
• #22: Problem: Up thrust constants are not designed to absorb lateral movement.  The side to side movement of the pipe caused the bearings to become damaged and eventually fail. 
• #23: Example of the ability to retro-fit support components where the initial design parameters did not foresee all of the loads / movements which would be seen during operation Solution: Since the constants cannot be reinstalled to change the direction of the force caused by the movement, slide plates and new shafts must be installed. Piping Technology and Products, designed a shaft that had a washer on the outside surface of the bearings to reinforce the bearing and prevent it from coming apart.  To further reduce the force of friction, slide plates were added between the top of the load table and the bottom of the pipe support. 
• #24: Insulated Supports Case… Case: Over 116 hot shoes for various sizes of large bore high energy steam lines failed. This caused the Energy Center to completely shut down due to safety concerns and the potential for pipe and/or equipment failure. The original vendor replaced the supports with the same type of supports, and they failed once again. PT&P was called in to survey the site and found that the type of pipe support used was not suited for the service conditions. http://www.pipingtech.com/news/enews/2005/090705.htm W:\\digital_camera\\Digital Album\\images\\Product Photos\\Competitor Products (field service survey and suggested replacement)
• #25: Because the elevations of all the piping were fixed, PT&P had to develop a pipe support design that would dissipate heat, in order to protect the PTFE, 25% glass filled slide plates from thermal damage. Natural Draft Air Cooling has several advantages over previous designs: 1. Since the insulation does not carry any mechanical load, it can be chosen solely on the basis of its thermal properties. In particular, cyclic loading, which has caused insulation failure, is not a problem. 2. The support provides effective restraint for all six possible components of loads, X, Y, Z-Rotational and Translational. In particular, axial and Torsional loads are readily accommodated. These represent difficulties for supports which rely on the insulation. 3. It is easily installed in the field and is attached to the pipe with a standard bolted pipe clamp. Thus, there is no field welding. The line temperatures ranged from 650°F to 1100°F. PT&P performed full EPC services and manufactured all of the supports for this project. Finite Element Analysis was also performed.
• #26: The top two pictures show the restoration of insulation after installation of new shoes The bottom two pictures show the steam lines after installation PT&P designed the solution needed for this dilemma and acquired a new patent for a pipe support with two clamps that are similar to the Figure 50 light two bolt pipe clamp. Each shoe is attached to a steel plate which is designed to carry the design load, and is shape optimized to minimize heat flow from the pipe.
• #27: Request from site personnel to provide means of increasing the durability of factory finish Major cause of concern: rusting on exterior / interior of standard components Review of existing design(s) included: 1.) Standard finishes available 2.) Method of maintaining integrity of surface finish through all phases of manufacture and assembly
• #28: Resolution incorporated use of HDG on all metallic surfaces and neoprene coating (pliable) on coils Secondary method of preserving coating involved “bolted design” of assemblies. This allowed all subassemblies to be galvanized prior to final assembly and required only bolting of subassemblies – no welding required after components have been galvanized
• #29: Examples of alternative coatings used for various specifications Environments where zinc (with HDG finish) is not permitted Environments where chemically resistant coatings are required Sites where color codes are used to specify equipments location or service Sub-sea environments where constant exposure to saltwater is expected
• #30: Examples where horizontal forces are generated at load carrying supports due to friction These horizontal forces can be reduced by using slide plates at the points of contact between the support and the moving pipe line By reducing these horizontal forces we can insure proper function of the support components (for example, reducing the friction forces the constant spring load table reduces the stress placed on the roller bearing, thereby permitting the load table to accurately follow the pipe during it’s vertical travel
• #31: Examples where under loading / overloading or over extending of supports would cause detrimental effects Functionality of supports could be comprised Excessive stresses could be transferred directly to the piping system or to surrounding equipment Provisions can be made using limit rods which would prevent spring supports or expansion joints, as shown, from exceeding a maximum range of movement and / or loading
• #32: Combination slide plate materials, including stainless steel and phosphorus bronze used to support vessels The carbon steel base plate will be securely anchored to a foundation Instead of welding, the lower slide plate will be affixed to the carbon steel base by countersunk attachment bolts The upper slide plate is fabricated from a phosphorus bronze plate with machined grooves on the underside The grooves allow lubrication between the contact surfaces of the upper and lower slide plates
• #33: The grease is replenished through the zert fitting pictured here The stainless steel is polished to achieve a low coefficient of friction Countersunk bolts are used to avoid interference The hole you see to the right of the slide plate is the access point for pouring the grout after installation