Engineered Spring Supports V.2

Editor's Notes

1. Display this slide before the presentation begins, while viewers are joining…. Do not say what is on slide…. Switch to next slide before welcoming Welcome To listen to the audio portion: 1.) Make sure you select speakers or headphones are on and turned up. OR 2.) Dial the phone number listed in your confirmation e-mail, for the United States, [ 9:00 am Time Slot : (1) 516-453-0014, Access Code: 410-064-727] [ 2:00 pm Time Slot : (1) 323-417-4600, Access Code: 293-235-526] , * If you are located outside the U.S.: please refer to your confirmation e-mail for a list of phone numbers to call for your area.
2. Hello everyone, I would like to welcome you to our Webinar on Engineered Spring Supports. The Webinar today is hosted by Piping Technology & Products. I am Jerry Godina and I will be your presenter. If you would like to join in on the audio portion of the presentation, please make sure you select speakers/headphones in the audio choice box and double check that your volume is turned up. You can also listen to us by telephone, for the United States, just dial: [ 9:00 am Time Slot : (1) 516-453-0014, Access Code: 410-064-727 ] [ 2:00 pm Time Slot : (1) 323-417-4600, Access Code: 293-235-526] , for countries other than the US, please refer to the list of numbers in your confirmation e-mail. 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 or if you prefer, you can ask questions after the presentation during our “Questions and Answers Session.”
3. 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.
4. The main purpose of an engineered spring support is two-fold: 1.) To uphold a specific load, including the weight of the pipe, commodity, flanges, valves, refractory, insulation, etc. AND 2.) To allow the supported load to travel through a predetermined thermal deflection cycle from its installed condition to its operational condition. A few types of engineered spring supports are shown here: Variable spring supports are used where: 1.) Relatively small thermal deflections, usually less than or equal to two inches (2 " ) are anticipated. AND 2.) A difference in the supported load from the installed to the operating condition is acceptable. We carry a substantial amount of variable springs in our inventory which can accommodate loads up to five-thousand pounds (5,000 lb.) “ Big ton” springs are used for very large load conditions where standard variable springs are too small. Constant spring supports are utilized when: 1.) The supported load cannot vary between the installed and operating position. AND/OR 2.) Large thermal growth is anticipated.
5. Figure 1 is a variable spring support designed to support piping from below, directly from the floor or supporting steel. Adjustment is made by inserting a bar into holes in the load column and turning the load column as a jack screw. The base plate is bolted to the case and has four holes for fastening. Figure 2 is a variable spring hanger designed to support piping from above. Figure 3 shows a constant load hanger which is typically used to support piping subject to vertical movement.
6. Variables use coiled springs to support a load and allow movement. The resistance of the coil to a load changes during compression, which is why these devices are called “variables.” There are many different designs for variable supports, we use A through G to describe seven different physical connections to the supporting structure. A-E and G are hangers suspended from structural members and type-F is a base support that rest on the supporting surface. All our variables are available in short springs, standard springs, double springs, triple springs or quadruple springs.
7. Type A variable spring supports are furnished with a threaded bushing in the top plate, providing for a simple rod attachment for the upper connection.
8. Types B and C variables are furnished with one or two lugs welded to the top cap plate of the casting. Type D variable permits adjustment from the top, by turning the nuts on the hanger rod against the load column which protrudes through the top. Type E variable spring permits rod adjustment from either above or below the spring. This type of spring can be set above the supporting steel.
9. Type F is designed to support piping from below, directly from the floor or supporting steel. The base plate is bolted to the case and has four slots for fastening. An interesting feature of F-type variables is that the installed height can be adjusted independently of any load adjustment.
10. A type G spring support assembly is formed by welding two standard spring assemblies to the ends of a pair of channels. This type of variable can accommodate unusually heavy loads and is adaptable for avoiding interference in spaces where headroom is limited. Travel stops are inserted and strapped in place to maintain the load for the assembly installation. The “g-can” pictured here was manufactured for a Petrochemical Plant. As a side note, you may notice that the travel stops have been chained to the spring housing. This is an optional feature available on all spring supports which prevents loss of the travel stops after the assembly is put into service.
11. Special Features can be provided if required: --lifting lugs can be helpful for installing large hangers --Upper and lower limit stops --Collars --Special Paint --Guided load columns --Extended load columns --Chained travel stops --Jacking Bolts --Type F PTFE, 25% glass filled
12. The way a variable spring support responds to an applied load depends on the coil or coils inside the casing. Each coil arrangement has a spring rate expressed in units of pounds/inch (or kilograms/millimeters) of compression. The required coil size is determined by load while the required number of coils (length) is determined by the anticipated range of movement. A longer coil or coils placed in series will provide greater travel for similar loads. We use PTP-1, PTP-2, PTP-4, PTP-6, and PTP-8 to designate the five standard coil arrangements we employ to increase the working range of travel of variable supports.
13. The Load and Travel Tables are color-coded to identify the travel and spring rates for each PTP figure number.* These tables can be used to select the PTP Figure Number and size required for a particular application. The twenty-three columns designated 00, 10, 20, ..., 220 identify the size and spring rate of coils used in the variables. The larger numbers have higher spring rates and are used to support greater loads. The recommended working range of loads for each size is shown between the red lines in the tables. The center of the working range is colored blue. Selecting variables with the loads within the working range provides a reserve above and below to insure the coil can function inside the casing. In using the Load and Travel Table to choose the proper variable support, it is best to have the operating (hot) load and an amount and direction of expected movement. Variability is a key criterion in selecting the figure number and size.
14. Example: Given the following design parameters: A.) Operating Load: 3000 B.) Installed Load: 3300 C.) Movement: ½ " Step 1: Determine a theoretical spring rate: ∆ Load / Movement  (3300-3000)/ ½ "  600 Step 2: Review Load and Travel Table Chart
15. Step 3: Review Load and Travel Table Chart Step 4: Check Variability Factor Variability is the percentage of change in the supporting force between the operating (hot) and installed (cold) positions calculated as shown: VARIABILITY = (Spring rate * movement ) /Operating Load VARIABILITY = (600 ∙ ½") / 3000  0.1 equal to 10% ≤ 25% Final Answer: PTP-2-130 Good practice, as specified by MSS SP-58, is to choose a support with variability less than or equal to 25%. Always try to choose a variable with the operating (hot) load near the center line (blue) of the working range in the Load and Travel Table. If you have a situation in which you cannot select a standard variable which has both the operating load and the installed load within the working range, contact us and we will help you determine alternatives.
16. Each variable spring we build is placed in a load cell and calibrated to the design load and movement. For the next three slides, we will go through the steps in loading a spring can. This particular spring can has a cut-away view for demonstration purposes. The first step is to check the hot and cold loads on the assembly drawing. The second step is to compress the spring to solid and release three times total. Then you will need to zero out the load cell before you compress the spring to the specified cold load. Mark the cold load location on the can, then measure for the travel stop length. Next you will need to compress the spring to the specified hot load.
17. Mark the hot location on the spring can, then measure the distance between the loads. The distance should match the desired travel. Compress the spring to the cold load and place the travel stops in. Release the load and check the travel stops. Remove the spring from the cage to a table using a hoist.
18. When adding the name tag and straps, first you need to drill and hammer the rivets into place. The name plates show the position where the pressure plate meets the coil at the operating (hot) load and the installed (cold) load positions. The name plate also shows the figure number, size, spring rate, and the customers designated mark or tag number. Measure the remaining slot for hydro-test stops Put the stops in place, strap them down, measure and lastly, adjust the load flange height if necessary. That concludes the section on variable springs. I would like to remind you, that if you have any questions, just type them to us using the chat box in the upper right hand corner. You can also pop the chat box out, so it doesn’t minimize during idol periods. Just press the two arrows on the left of the chat box and drag it where you want it.
19. “ Big Ton” is the name PT&P uses for a special type of variable spring support which was developed for the petrochemical industry. Many of these supports have been in service for more than 20 years. A typical big ton will have a rectangular array of coil springs supporting a pressure plate which in turn support a top load flange. Big tons provide the designer with options that are not available with typical spring supports, because they can support vessels and other components which have piping attached to them. The piping designer can choose to support these components and thus reduce loads which would be transferred to the piping. This is often a more economical and stable design for the entire systems. This type of support is used where two important characteristics in spring supports are necessary: - Extremely stable: Base supports springs of this design are frequently used under horizontal pressure vessel saddle supports in combination with slide plates or roller supports. Our Big Ton design lends itself ideally to this support situation. Type-F design is sufficient where there is a minimal amount of lateral movement, but where the combination of heavy loads and thermal expansion are required, big ton industrial springs should be your choice. - Heavy Loads: The big tons’ multi-spring design lends itself to supporting very high loads. Loads up to 200,000 pounds can be handled with no problems.
20. Note: division & centering plates divide 2 coils stacked on top of each other and the little guides in side that holds spring in place
21. 1 st Picture: base measures 63" square and the top load flange measures 55" square. One of the springs has an overall height of 22-7/16" and the other has an overall height of 28-5/8". Both big ton springs are custom designed and fabricated from carbon steel with a hot-dipped galvanized finish. The top of the load flange is covered by a stainless steel slide plate. One of the big ton springs is designed with a operating load of 126,000 lb. and the other with an operating load of 225,000 lb. Prior to fabrication, all of the coils, within the frame, were individually tested to insure correct spring rate and load capacity. After the units are fabricated, the entire assembly is tested throughout the entire load/travel range. 2 nd Picture: Dimensions: 42" x 36" x 32" Load: 25,400 lb. Movement: 7/16" Upward Spring Rate: 4400 lb/in. http://www.pipingtech.com/news/arc_pw_2008/engps2008_02.htm
22. 1 st Picture: 8 foot long big ton variable spring assembly designed for a local area refinery Fabricated from carbon steel components with a painted finish Top of load flange has three PTFE, 25% glass filled slide plates Base is 96 " x 18 " and installed height is 24 " Operating load: 76,800 lb. and downward travel: 0.894 " Prior to fabrication, each of the coils were individually tested to insure correct spring rate and load capacity. After fabrication, the entire assembly was tested throughout the entire load and travel range. 2 nd Picture: Example of a “mini” big ton where loads/movement matched standard spring, but overall height was restricted Standard variable spring could not fit; solution was to use combination of smaller (shorter) coils which matched load carrying capability; short overall height could be maintained
23. PT&P’s constant support hangers are principally used to support pipes and equipment subjected to vertical movement due to thermal expansion at locations where transfer of stress to other supports or equipment can be critical. The maximum recommended variation according to MSS standard from the operating load is 25% for variable spring hangers. If the load variability between the hot and cold loads exceed 25%, and/or around sensitive rotating equipment where a load variation could be harmful, a constant support hanger should be used. The constant resistance to a load is achieved by combining a spring coil with a cam which rotates about a main pivot point. The cam is designed such that the distances from the main pivot changes to compensate for the variable resistance during compression of the coil. The MSS standard provides for a tolerance of 6% in the constant load through the travel range. Our constant support hangers are designed per MSS, ANSI, and ASME standards.
24. Constant hangers are principally used to support pipes and equipment subjected to vertical movement due to thermal expansion at locations where transfer to stress and other supports or equipment can be critical. The maximum recommended variation according to MSS standard from the operating load is 25% for variable spring hangers. If the variation exceeds 25%, a constant support hanger should be used. The constant resistance to a load is achieved by combining a spring coil with a cam which rotates about a main pivot point. The cam is designed such that the distances from the main pivot changes to compensate for the variable resistance during compression of the coil. The MSS standard provides for a tolerance of 6% in the constant load through the travel range. Our constant support hangers are designed per MSS, ANSI, and ASME standards.
25. Horizontal constants are used mostly when vertical space is not available; the spring can is aligned horizontally, while permitting vertical movements. The drawing on the left is a figure 200 A-type constant. This type of support is useful where the rod take-out is small and will be bolted directly under the beam eliminating the space used up by the mounting lugs. Pictured on the right is a PT&P figure 200 B-type constant.
26. These 200 C-type constant spring supports are fabricated from A-36 carbon steel and are designed for a load ranging between 17,800 lb. and 25,600 lb. They have a downward travel range between 12 1/2" and 16" and maintains a constant load throughout the designed travel. The diameter of the spring coil housing is 21". The design includes a universal locking device capable of locking the hanger rod at any desired position . (fully adjustable) It also includes lifting lugs that aid in installing the constant in the field. Standard load and travel testing was performed before shipping to a steam plant. --Similar to variable spring --Standard is to utilize pin for locking and one location --Universal locking device allows locking at any location within the travel range --Useful when taking spring out of service http://www.pipingtech.com/news/arc_pw_2008/engps2008_04.htm
27. Vertical constants are used mainly when horizontal space is not available. Pictured on the right is a PT&P figure 100 B-type vertical constant. Notice the use of double-pin suspension instead of single-point suspension. This will eliminate any constant rotation as the pipe moves due to thermal expansion.
28. B-Type vertical constants for a power plant in Kentucky --Carbon steel hardware and structure --Travel capacity: 7 " to 8 ½ " --Size: 4 " to 6 " --Weight: 690 lb. to 2850 lb.
29. Left Picture: --The U-Type constants pictured on the left are fabricated from A36 carbon steel for a power plant in Thailand. --They are designed to handle a load of 24,000 lb. --These particular constants are 80 " in length and capable of 3 " of total upward travel. Right Picture: --Maximum travel per catalog = 20" and this constant has a design travel of 46" --The frame dimensions are: W 40" x H 75" x L 142" --The internal cam component in excess of 74" --Uses an oversized spring --Utilizes rollers and PTFE, 25% glass filled slide plates to reduce the friction resulting from axial movements Job # 68264
30. Example: Given the Following Design Parameters: a.) Operating Load: 3000 b.) Actual Travel: 4 ⅜" Step 1: Determine Total Travel: a.) When Actual Travel is < 5" Total Travel = Actual Travel + 1"  Rounded up to nearest ½" Total Travel = 4 ⅜" + 1" = 5 ⅜"  5 ½" (EXAMPLE) b.) When Actual Travel is ≥ 5" Total Travel = Actual Travel + 20%  Rounded up to nearest ½"
31. Step 2: Review Load and Travel Table Chart Final Answer: Size 41
32. If the piping system has inadequate support, static loads can cause multiple problems, like: Leaking flanges Pump and turbine problems, mainly concerning the bearings, seals and misalignment of flanges Sagging lines and/or liquid trapped in low sections And an increase in system stresses can result in piping failures as well
33. When inspecting a spring support, the first thing you want to do is: Visually inspect each spring hanger in accordance with the ten point operational integrity check which is pictured here. After the ten-point visual inspection, you should tag each spring hanger as good, adjust, or replace then issue a field summary report.
34. To adjust a spring hanger after inspection, set to the desired position by turning the turnbuckles and load column. When the nameplate is present indicating the design hot load, adjustments can be made during operation, but a cold load adjustment needs to be made during a shutdown. Re-calibration: Missing name plate Variables with load range > 15,000 lb. All constant support assemblies Spring is in good operating condition Field time & equipment cost required is less than the cost of new spring hanger
35. Pictured here are non-PT&P supports our field service technicians found in the field. Right Picture: Notice in the right picture, the load indicator scales are missing or painted over. While it can be stated that the supports are taking load, it is extremely difficult for field personnel to distinguish the precise load these assemblies are holding. Left Picture: the setting on this variable spring is correct by the load indicator label to the right of the spring
36. Again, this support on the left is out of adjustment and the slide plate is no longer attached to the load flange. Pictured on the right is a C-Type variable spring support with the travel stop left in. Failure to remove the travel stops would lock the spring coil in position and render the support inoperable. Note that these supports are not fabricated by PT&P.
37. When deciding on whether to replace a spring can or not, consider the corrosion, fatigue, rust damage, and the modification of surrounding equipment and piping. Let’s look at the average life expectancy of a spring hanger: An unprotected spring hanger will last anywhere between fifteen (15) and twenty (20) years. If the hardware is galvanized, which is PT&P’s standard, the spring hanger will last between fifteen (15) and thirty (30) years. And if the springs are coated with Neoprene, it will last fifteen (15) to thirty (30) years. Neoprene protects the spring coil from many corrosives without affecting the flex life of the coil. In some cases, such as in a furnace installation, temperatures are too high for neoprene. We apply paint or other types of coatings for this situation. Neoprene is recommended only for operating temperatures up to 225 degrees F. Corrosion and fatigue are the main factors that contribute to the deterioration of a spring hanger assembly.
38. The above examples are not fabricated by PT&P and are indicative of supports which show limited functionality. The pair of base-type springs on the left exhibit significant rusting of the spring coil. Extensive deterioration of the coils would alter the spring rate and ultimately reduce the load carrying capability of the assembly. The two examples on the right show variable spring assemblies which have not been loaded. The load indicator at the top of the slot is a clear indication that either 1.) the springs have been unloaded and never returned to service or 2.) the assemblies were improperly sized for the load.
39. A few thoughts during shutdown: Are the lines and equipment temporarily supported while repairs are being made? To prevent having to readjust the spring, I need to re-install the travel stops. If the name plate is missing, stencil the proper installed and operating positions or provide loads for re-calibration.
40. While installing, securely attach the spring to the existing structure per the spring support design. If required, attach a hanger rod to the fabricated load column or turnbuckle. Next attach other related hardware, for example, here is a constant in the field with the rod, turnbuckle, weldless eye nut and welded beam attachment.
41. After hydro-testing, remove the travel stops as pictured here. And the last step in installation is to verify that the load indicator is at the desired setting (cold/hot load)
42. Remember: When selecting springs, determine the location of the hanger, calculate the hanger load and the thermal movement of the piping at the location. And when sizing a variable spring: first, determine the theoretical spring rate, r eview the load and travel table chart and then lastly, check the variability factor When sizing a constant spring: first, determine the total travel before referencing the load and travel table chart For optimum performance, follow the installation guidelines from attaching the spring to the existing structure to setting the load indicator. When inspecting springs: Utilize the 10 Point Operational Integrity Check to make sure your springs are in good working order. Plan now to replace damaged and/or improperly sized springs that could ultimately lead to catastrophic failure.
43. I want to thank you for joining Piping Technology & Products Webinar on Engineered Spring Supports. Please forward any additional question or inquiries to us at info@pipingtech.com or visit our website at www.pipingtech.com Please join us next time for our Pre-Insulated Pipe Supports Webinar scheduled for September 3 rd . Registration will be open by tomorrow for either 9am or 2pm. I’m Jerry Godina and have a good day.