Re: Hyrdo test

Things are never simple.

Hydrostatic test pressures????

Depends on Jurisdiction, such as FRA, ASME for new construction or alterations, NBIC for repairs and alterations, Local requirements, and so forth.

All of the test pressures listed above are correct in that regard.

However there may be better methods then a 150% hydro. NDE, such as LPT,MPT,RT, and anglebeam UT. Full advantage should be taken of modern technology.

150% hydro is required by Code for new construction and most alterations. If a boiler has been out of service for an extended period it may be wise. This is to find "gross defects" and major problems. There are better ways for a leak test only.

Why risk incuring damage,perhaps hidden,to a boiler that has been in safe operation for a tube replacement or a routine check?

In anycase I have witnessed thousands of pressure tests over the years.Some good and some bad. Some to destruction for proof testing....which is always kind of fun!

One must meet Jurisdictional requirements, but why risk damage when a 150%/125% test is not required for a proper result?

That is why as an AI/State Inspector I will not ask for a full hydro unless it is required by Code or Law.

Some of this equipment is old and somewhat tired, if properly cared for may provide many more years of safe service.

Dean D Cockroft