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?
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.
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.
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.