ASME B31.3 Leak Tests

[Sharik]

If a flanged valve is replaced, in kind, on an existing B31.3 process piping system, would this installation require a full hydrostatic test? Or is a service test sufficient.

No welding is performed and the valve was pressure tested by the manufacturer, documentation is available.

 

[ColonelSanders83]

According to ASME PCC-2-2008 Repair of pressure piping and equipment", whatever was required by the original design and contruction code or post contruction code is what will be required for service. Part 3 Aricle 3.1 sect 6.1.

From the looks of it you will be stuck with the same test originally performed on the system.

Just my two cents worth.

A question properly stated is a problem half solved.

Always remember, free advice is worth exactly what you pay for it!

http://www.ap-dynamics.ab.ca/

 

[StevenHPerry]

You need to satisfy the inspector, whoever that may be.

In my non-inspector opinion this isn't a repair of pressure piping. You're swapping out a valve. The piping is unchanged.

If you were to swap out a pump casing for an equal pump casing, would you hydro the suction and discharge lines that flange up to the pump? Same concept, except the pressure change is reversed.

On the other hand, I've seen more than a few valves delivered with leaks even though they were tested by the name-brand, made-in-the-USA manufacturer.

- Steve Perry

 

[racookpe1978]

If it is a brand new valve - one that has not been hydro tested or one you cannot track the hydro pressure data back to - then you must hydro the valve (or pipe or new material. You have to be able to certify to the inspector that all material has been hydro'ed.

But, if it is an old valve, then you need the service pressure test to verify you've done the repair (or removal and installation) properly. Here, present to the inspector the previous hydro test cert's, and plan on a service (operational) pressure test.

Don't try to make your case without the documents and pressure test data actually in hand however.

 

[Sharik]

But from the same Code, 6.2 allows for alternate testing (which could include only a service test) as long as the requirements of 6.2.2 (which refers to 4.4 and 5.2) are met for mechanical tie-ins.

So the way I read it, in this instance it is possible for the Owner to specify a Service Test and the requirements of 4.4 and 5.2.

Correct?

 

[Sharik]

This would be a new valve replacement with supporting pressure test documentation from the valve manufacturer.

 

[metengr]

If a flanged valve is replaced, in kind, on an existing B31.3 process piping system, would this installation require a full hydrostatic test? Or is a service test sufficient.

No, a hydrotest is not required if the line had received an initial hydrotest.

No welding is performed and the valve was pressure tested by the manufacturer, documentation is available.

Your rationale above is sufficient.

 

[bob74r]

If you can prove that the valve has been tested and no welding has been performed on the line or valve, I don't see why any inspector would require a re-hydro test of the line for a simple valve exchange (imagine the hundreds of thousands of dollars wasted in live plants if this was the case).
I'm assuming this is a line that was already in service (hence changing out a valve)
Depending on the service and specification requirements a hydro test would be an unnecessary cost (flushing prior to testing, additional blind installations, removal of test medium, air/steam blows,corrosion inhibitor drying, etc..)
Add all these things together and it can get expansive real quick. If your inspector is really worried about the flanges leaking try a "closure boltup" have him present to inspect the flange faces and witness the torques.
If the inspector still insists on a Re-Hydro , I foresee him looking for a new job in the near future.