ASME/ANSI B 31.3 ASTM A WPL 6 on Pressure Piping

[bmoorthy]

While i have asked for a question in Boiler and PV Forum,on the related subject, this question is slightly different from that one, hence in this forum

Please refer to the Clause 7.4 from A 420 WPL6

7.4 When the fittings are to be post-weld heat treated after being welded by the purchaser and when so specified in the order, the test specimens shall be subjected to the same post-weld heat treatment. The purchaser shall use the postweld heat treatment shown in Table 2, unless otherwise
specified in the order.

If One orders a fitting fo 20" diameter 25 mm thick (Beveled butt weld ends) and this is going to be used for welding in the piping (The Specification that went to the fitting manufactuer clearly specifies that the fitting are meant for the welding on ANSI/ASME B 31.3 piping),

1) is it necessary that the fitting manufacturer test the specimen after PWHT? (because it is a well known fact that any welding beyond 19mm requires PWHT as per B 31.3-For butt joints)

2) Is it the responsibility of the purchaser to specify that the fitting will be subject to PWHT?

3) if the purchaser did not specify and supplier supplied the fittings as per standard (Not testing after simulated heat treatment, but only after the heat treatment that the fitting under went at the fitting manufacturing shop), is it OK to use in B 31.3 piping system and heat treat them (With out performing any additonal destructive tests)

 

[metengr]

1) is it necessary that the fitting manufacturer test the specimen after PWHT? (because it is a well known fact that any welding beyond 19mm requires PWHT as per B 31.3-For butt joints)

2) Is it the responsibility of the purchaser to specify that the fitting will be subject to PWHT?

3) if the purchaser did not specify and supplier supplied the fittings as per standard (Not testing after simulated heat treatment, but only after the heat treatment that the fitting under went at the fitting manufacturing shop), is it OK to use in B 31.3 piping system and heat treat them (With out performing any additonal destructive tests)

Reply;
(1) No, unless specified by the Purchaser.
(2) No
(3) Refer to your WPS and B31.3 Code requirements

 

[BigInch]

You and/or your construction department's welding engineer are responsible for developing the appropriate preheat, weld procedure and PWHT, such that you do not derate the component and manage to make a satsifactory joint.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[SJones]

Isn't the answer to 2) a "Yes"? It can't be down to the manufacturer to work out whether a PWHT is going to be used?

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[BigInch]

Rightly or wrongly, I've never indicated to a mfgr that PWHT will be performed during construction. First, if the mfgr supplied to specification, his responsibilities are fulfilled and end. Secondly, what would the mfgr do differently as far as actually supplying a production fitting itself is concerned, if it was indicated on the PO that the fitting would be subject to PWHT during construction, or if it wasn't so indicated?

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[stanweld]

The purchaser must specify in its P.O. to the manufacturer/supplier that the added heat treatments (for PWHT) are required for mechanical testing. Only the mechanical test specimens (coupons) are subject to the additional heat treatment; the fittings, as supplied by the manufacturer, are not subject to the additional heat treatment.

 

[BigInch]

Exactly. He's got nothing else to do with the fittings themselves, if #2 box is checked or not.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[SJones]

But it is still the responsibility of the purchaser, i.e. "Yes" to question 2, in order to satisfy any specification that is referencing A420 without modification (which is where the thread originator is coming from because he has been caught out by such an instance).

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04