BOLTS USED DURING HYDROTEST

[cris973]

We have to hydrotest some vessels as per ASME VIII div.1 Code prior to "U" stamp them, but PTFE coated bolts required by Specification have not been delivered yet.
The question is: can we use other in-stock bolts suitable for the same pressure requirements, but not PTFE coated, to perform the hydrotest?
I cannot find any Code requirement for the chioce of bolting during hydrotest.

Thank you very much for support.

Cristiano

 

[metengr]

cris973;
Yes. The use of hardware and procedure to support a Code hydrostatic test is up to the organization taking responsibility for the hydro test, and concurrence from the AI.

 

[bmoorthy]

Is there a disposition for this in the ASME or in the interpretation.

Aslo please let us know the disposition for Gaskets

 

[JoeTank]

It is common practice in a vessel shop to use stock bolts for the hydrotest. After hydrotest, vessels are usually drained and cleaned. The flanges are normally protected during shipment with wooden covers bolted to the flange face. So, it is very seldom that the final bolts are used for hydrotest. I am not aware of a specific statement in the ASME VIII Code about this common practice.

Joe Tank

 

[chicopee]

The purpose of a hydrostatic test is to test the integrity of the vessel. Bolted connections really have nothing to do with integrity of vessel unlike riveted joints.

 

[arto]

Usually you can only use a gasket once, so plan for spares when you break the joint to swap out the bolts.