Hydrostatic Test

[Espcex92]

In execution of the hydrostatic test of a pressure vessel is necessary to measure the perimeter of the equipment before and after the test?
Why? Where is write?

 

[weldstan]

Not normally.

 

[mhopgood]

I have been involved in numerous hydrostatic tests and have never heard of this requirement. Typically the only requirements are a calibrated test gauge complete with calibration certificate, witness of the test by the AI, and inspection for leaks. Duration and pressure are dictated by the respective code you are using.

That being said, if it is written in a contract that the purchaser / owner would like this test performed and the company performing the testing has agreed to the contract then it is a valid requirement that should be performed. The purchaser / owner can pretty much request whatever they want over and above code requirements in a contract.

 

[jtseng123]

Espces92,
I guess you are afraid of the deformation, especially for large diameter, thin wall. Not just that, head wrinkling can happen.

 

[Compositepro]

Hydro test of DOT pressure vessels does measure expansion of the tank. This is done by water displacement.

 

[GenB]

It may be required for proof tests to check deformation %

 

[ZGZtanker]

In my experience with transport tanks, that can have two goals:

1.- Check that no permanent deformation takes place during the hydrostatic test

2.- Control a cold stretching procedure on austenitic stainless steel during hydrostatic test

 

[Gorostidi]

Never heard of that. Some standards limit the % of expansion during testing, but that is shown in the calculations if required. During testing this is not required.

 

[MechD]

Never heard of anyone doing this. We did have a rectangular vessel before & there was a requirement from the client to measure before and after testing to ensure no permanent deflection had occurred. Never been asked to do it on a cylindrical shell though so I doubt it's a design code requirement, likely just a client requirement.