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What acceptance criteria do you use for air testing the fabric expansion joints?

We do not air test fabric expansion joints; all welds are liquid penetrant tested.

How do you do the fatigue analysis of the bellows in high temperature application?

Why should we do a dye-penetrant test?

Dye-penetrant tests should be performed in order to check the integrity of the welds. At U.S. Bellows, all bellows undergo a ...Continue Reading

What are the quality tests that are conducted on expansion joints?

At U.S. Bellows, we perform a variety of tests: Burst Testing – The objective of the burst test is to determine ...Continue Reading

How do you service test an expansion joint?

Expansion joints are maintenance-free. They can only be tested if the expansion joint is supplied with 2-ply testable bellows using ...Continue Reading

How do you detect a crack in a fatigue testing machine?

Cracks on a fatigue testing machine are detected by the loss of internal pressure that is shown pressure gauge on the machine.

What is the difference between pneumatic testing and helium testing?

For pneumatic testing, air is used as the medium for testing and for helium testing they use helium, and the cost for ...Continue Reading

How long is a burst test on an expansion joint?

A burst test is performed under controlled conditions and pressure is applied over a period of one to two hours using the ...Continue Reading

What is blotting in a dye-penetrant test?

Blotting on a dye-penetrant test typically indicates a crack in the weld. Therefore, the crack would be repaired and the test performed ...Continue Reading

How do you do a fatigue life cycle test for bellows?

The bellows is placed on a test machine and allowed to cycle continually until the bellows fail.

What is the threshold pressure limitations of a fabric expansion joint?

Fabric Expansion Joints can withstand up to 3 PSIG (pounds per square inch gauge) or 100″ of water (H₂O) column ...Continue Reading

Does the expansion joint still work if the balancing side pressure is higher than the inline side?

The pressure is equal on both sides for a pressure balanced expansion joint. If the pressure difference is minor, it ...Continue Reading

What pressure do you recommend the bellows are tested to?

We recommend that the bellows be tested to 1.5 times the design pressure.

What is the pressure rating for an expansion joint?

The pressure rating is the maximum allowable pressure that the particular expansion joint can absorb. This is determined on a case-by-case basis.

What does pressure balance mean?

Pressure balance joints balance the pressure thrust forces inside of the expansion joint tie rods.

How do you attach a high pressure joint in a piping system?

In an axial piping system, the expansion joint should be located as close as possible to a main anchor. The first pipe ...Continue Reading

If a simple bellows is designed without limit rods (for operating cases), under a hydro test, do you recommend adding limit rods?

Yes, if they are testing just the expansion joint or if they are testing when installed, they have to make ...Continue Reading

What is the highest pressure that an expansion joint can take?

The pressure rating an expansion joint can take depends upon pipe size and temperature. Standard units from 3 inches to 24 inches ...Continue Reading

Where does the pressure thrust act in a single bellows turbine exhaust application?

If the expansion joint is not tied the pressure thrust will act on the turbine exhaust nozzle and the adjacent piping.

What are the pressure ratings specified in expansion bellows?

The pressure rating is the maximum allowable pressure to be used for that particular expansion joint. Each pressure rating is specified on ...Continue Reading