Use of in line weld test tool (IWT tool) for pressure testing of joint fulfills ASME B 31.3?

[Ishack]

Hi Experts,

A new WN flange is welded to the existing piping and hence the line need to be tested hydrostatically/pneumatically as per ASME B31.3. Is it acceptable to use in-line weld test tool (the tool that is used for pressure testing of joints especially flange to pipe/fittings joint) instead of flange tester to fulfill the requirement of pressure testing of piping system as per ASME B31.3.

regards,
Ishack M

 

[XL83NL]

My memory has left me here, but I believe that there's either some discussion in the B31.3 for incorporating such a method, or there's a code case made (or being prepared) for this. Im not sure if this method is approved at this moment. Maybe some other committee member scan help me?

 

[Ishack]

XL83NL, Thanks for your valuable feedback. It would be great if you can share a piece inf about the code cases. I have tried to find any interpretation that supports to use this kind f tool. But I believe flange tester fulfills the requirement of the above scenario (flange to existing piping which has been tested previously).

 

[TGS4]

It's not in B31.3, but you may find what you're looking for in ASME PCC-2.

 

[XL83NL]

Exactly what TGS4 said. Check PCC Case 100

 

[Ishack]

Great to know that there is code case available. But I have read it in conjunction with PCC-2 and my understanding is that the inline weld tool can be used when the system requires to test only the weld (eg:-shortening the section without the adition of new component in this case only weld becomes new and either side of the weld have already been tested previously). If a new flange is welded to the existing one, still the code caee 100 can be used provided the flange tester or other tools which will blank off the new flange so that new flange and weld will be under the pressure test. Correct me if my understanding is wrong.

 

[TGS4]

This might be more of a jurisdictional issue. Check with your local jurisdiction.

 

[lsone]

In this situation I have always used an inline testing tool that seals beyond the butt weld and is also flanged. This way you prove the integrity of the weld joint and also the ability of the flange face to seal. At any rate you have to prove the ability of the flanged connection via hydrostatic or pneumatic test UNLESSS you have a hydrostatic report from the flange vendor that satisfies the code requirement. Id also submit the flange hydrostatic report to the client and ensure they are on board with it. If they approve it you can now prove the weld with an inline testing tool that only tests the weld joint itself.

345.2.3 supports my thought process

 

[weldstan]

Testing the weld and replaced flange is often done on piping systems under B31.3 as indicated by Isone. I would say that we had done such a test over 100 times during the 20 years that I was involved.

 

[DekDee]

The requirements of B31.3 as far as I am aware are testing the welds and connected piping - not the actual flange connections.
A client may request a system hydrotest after all previously tested sub-assemblies are connected together but it is not a code requirement.
Not sure whose jurisdiction a replacement flange falls into after the B31.3 fabricated piping system has been put in to service ?

 

[Ishack]

DekDee, please see the quote from asme B31.3 below,

345.1 Required Leak Test
Prior to initial operation, and after completion of the
applicable examinations required by para. 341, each piping
system shall be tested to ensure tightness. The test
shall be a hydrostatic leak test in accordance with
para. 345.4 except as provided herein......
Also refer the below quote too....
(b) Flanged Joints. Flanged joints used to connect piping
components and subassemblies that have previously
been tested, and flanged joints at which a blank or blind
is used to isolate equipment or other piping during a test,
need not be leak tested in accordance with para. 345.1.

We must understand the entire piping system to be pressure tested as per ASME B31.3 which includes flange connection too..

 

[DekDee]

Ishack,
Read what you have posted

(b) Flanged Joints. Flanged joints used to connect piping
components and subassemblies that have previously
been tested, and flanged joints at which a blank or blind
is used to isolate equipment or other piping during a test,
need not be leak tested in accordance with para. 345.1.

If you hydrostatically test flanged sub-assemblies prior to assembly there is no code requirement to test the whole system once assembled.

 

[Ishack]

DekDee, Thanks for posting. You are absolutely right as flange connection need not be tested if it has been previously tested. But how about the flange?. My point is that component "flange" to be pressure tested if it is welded to the piping line, not just the weld that connects the flange to pipe/fittings (please refer the original question posted).

collective discussion will help very much.... Thanks for sharing and keep posting.

 

[DekDee]

Ishack,
Please read B31.3 regarding "Closure welds".
Many times a "Closure weld" is the pipe to weldneck flange that connects to a fixed item (eg. pump, tank, pressure vessel etc)
The flange itself is not leak tested, it is not pressure tested - the only thing tested is the pipe to flange weld by NDT.
That is why I mentioned jurisdiction - who is responsible for a B31.3 system after it has been placed in service ?