When designing specialty pipe supports or expansion joints, we can provide a 3D print that allows our customers to assess the design before it is sent to our shop for manufacturing. Providing our customers with a 3D printed model will help them have a better understanding of the product and its functionality.
Engineering and designing is done per EJMA equations as well as per the latest revisions of the ASME B31.3, ASME B31.1, and ASME Section 8, Division 1. U.S. Bellows designs are performed using in-house developed design software and calculations further checked using hand calculations. U.S. Bellows also has full in-house finite element analysis capabilities and we often use this methodology to prove designs.
Metal Forming:
Bellows Forming:
Machining:
Quality Control
Additionally, U.S. Bellows does extensive physical testing to prove designs. Each bellows and pipe expansion joint unit goes through in-process quality control controlled using a system of travelers. Final in-house inspection and testing is performed prior to shipping, based on customer requirements. U.S. Bellows has performed a variety of tests on pipe expansion joints ranging from X-Ray tests and hydrotest to helium leak tests (using a mass spectrometer). Our manufacturing shop also has ASME Section VIII CODE certification for jobs requiring CODE certification.
U.S. Bellows is highly experienced in various design and analysis techniques for piping systems. Given the parameters of your application, U.S. Bellows can use finite element analysis and conventional pipe stress analysis to provide you with an in-depth analysis portfolio that is presentable to your management and your client.
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See the photographs below is an example of a gimbal pipe expansion joint fabricated by U.S. Bellows. FEA was used to design the gimbal assembly.
The final product is shown after fabrication completion and then during installation in the plant.
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Below is Finite Element Analysis (FEA) on custom designed Tied Universal Pipe Expansion Joint
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Or click here to request assistance from PT&P’s Field Services
Pipe Expansion Joint Installation & Maintenance Guide
U.S. Bellows has extensive experience providing on-site services in quick-turn or emergency response situations. U.S. Bellows can provide on-site services for pipe expansion joints (as well as for pipe supports) which include the following:
U.S. Bellows is also available on a 24 x 7 basis to fulfill any emergency requirements that might arise. We have a system of stock pipe expansion joints as well as an “on-call” engineering and manufacturing team to meet any of your quick-turn and emergency requirements.
Inspection Checklist — Pipe Expansion Joints
For the quickest response in such an emergency type situation, fill-out the online request form and U.S. Bellows guarantees a response to your request within 30 minutes. Once we receive your request, we will made contact with you and understand the situation, U.S. Bellows will work hard to assist you.
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| Cracked Bellows in a Piping System | Corroded and Damaged Universal Metallic Pipe Expansion Joint |
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| Fatigue Failed Pipe Expansion Joint | Universal Metallic Pipe Expansion Joint with Squirm Damage | Rusted & Corroded Metallic Pipe Expansion Joint |
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| Immediate Refurbishment of a 3″ O.A.L Single Bellow with Flanges for a Marine Vessel in Texas | Failed Fabric Pipe Expansion Joint Brought in to Replace Fabric Belt |
We are here to help you 24 hours a day, 7 days a week.
With a large inventory of stock components for expansion joints and a shop that runs 3 shifts around the clock, U.S. Bellows can quickly assemble and ship products for any situation.
Fill out our emergency service form below and we’ll immediately be notified. A representative will call you back within 30 minutes to assist you. Our response is guaranteed in the evenings and on weekends and holidays.
An Alaskan petroleum firm called upon the U.S. Bellows Field Service Team on a Friday evening to aid them in an immediate replacement of a defective 48″ diameter pipe expansion joint. The pipe expansion joint was damaged during the plant startup when a G417 pump suddenly failed. A replacement pipe expansion joint was designed, manufactured and shipped the next day. It was installed at the customer’s location within two days of receiving the call.
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Friday, 5:30pm: U.S. Bellows received an emergency call regarding a deformed 48″ pipe expansion joint |
Saturday: The replacement pipe expansion joint is manufactured and ready for shipment. |
Sunday: The new pipe expansion joint is installed on-site. |
How it Works:
Objective: The objective of this test is to check for leakage or cracks in the welding.
What We Do: The bellows is completely filled with a liquid such as water. Pressure is slowly applied to the liquid until the required pressure is reached. This pressure is held for at least 30 minutes at which point the component is inspected visually to locate leaks.
Completion: If a leak is present, the welds will be repaired after releasing the hydro test pressure.
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| Bellows are pressurized | Pressure is observed |
Objective: This test is performed to insure there are no weld defects such as surface cracking or weld discontinuities before and after forming the bellows.
What We Do: The weld surface is thoroughly cleaned and a red penetrant dye is applied to the surface of the weld and allowed to soak for a period of time. The dye is then removed and a white powder is sprayed on the weld surface that performs a blotting action.
After Completion: An indication of the dye with a white background characterizes the weld surface discontinuities of the bellows longitudinal seam weld. This testing before and after the bellows forming process ensures a sound quality bellows seam weld.
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Objective: The objective of the fatigue testing is essentially to verify how many cycles a bellows can withstand before failing.
What we do: The bellows is placed on the “cycle-test machine” and bolted to a hydraulic plunger. Each cycle is counted as the bellows is compressed and returned to neutral.
This video shows an expansion joint bellows being subjected to a cycle test as required by the customer. The expansion joint is compressed and expanded through its specified design movement of 1 and 1/4 inches to verify the calculated lifespan of 30,000 cycles. The number of completed cycles is recorded throughout the duration of the test.
Read MoreU.S. Bellows has an inventory of over 1500 stock bellows for your quick-turn/emergency requirements. Using our inventory, we can quickly assemble and ship a variety of expansion joints including single, single tied, universal, elbow pressure balanced and in-line pressure balanced expansion joints. Stock bellows are available from 2″ to 24″ diameter and in three pressure values:
U.S. Bellows, Inc. does extensive physical testing ranging from X-Ray tests and Hydrotests to Helium Leak tests (using a mass spectrometer.) Each bellows and pipe expansion joint unit goes through in-process quality control using a system of travelers. Final in-house inspection and testing are performed prior to shipping. Our manufacturing shop also has ASME Section VIII CODE certification.
Fatigue testing is essentially verifying how many cycles a bellows can withstand before failing. The bellows is placed on the “cycle-test machine” and bolted to a hydraulic plunger. Each cycle is counted as the bellows is compressed and returned to neutral.
View a Fatigue Test Verifying a Cycle Life of 30,000 (VIDEO)
The objective of the burst test is to determine the ultimate pressure resistance, primarily conducted on bellows. Normally, hydraulic pressure is slowly increased until failure occurs. Pressure balanced pipe expansion joints are designed to maintain a constant volume through the use of a compensating bellows.
Liquid dye and a white powder observant are used to locate leaks or cracks in the bellows attachment welds. This test is performed for long seam welds before and after forming the bellows.
During a hydro-test, the bellows is completely filled with liquid until a desired pressure is reached. The bellows is pressurized for 30 minutes to locate leaks or cracks in the welding.
The bellows is filled with pressurized helium and then “sniffed” to detect leaks indicated by a mass spectrometer.
Additional Product Testing:
Objective: The objective of the helium test is to locate and calibrate leaks.
What We Do: The unit is filled with pressurized helium and the outside is “sniffed” to detect leaks which are indicated by a mass spectrometer.
After Completion: Once the test is completed, leak areas can be passed, rejected or repaired.
Objective: The objective of the burst test is to determine the ultimate pressure resistance that a bellows can absorb prior to failure. Burst tests help determine the margin of safety and safety factor to be used in a specialized bellows design.
What We Do: During a burst test, hydrostatic pressure is slowly increased until failure occurs, which usually happens in one to two hours. Burst testing is conducted at ambient temperatures to determine a bellows pressure rating. We follow all the necessary safety precautions for personnel involved, such as placing the bellows in a high strength steel cage and using a safety shut-off switch.
After Completion: Based on the burst test results, a safety factor is applied, thus establishing the ultimate pressure rating.
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| Burst Test to 800 psig on a 304 Stainless Steel Bellows | Q.C. Inspecting the Bellows After a Burst Test |
