SA 420 WPL6 in U stamped Pressure vessel
SA 420 WPL6 in U stamped Pressure vessel
(OP)
In a U stamped Pressure vessel SA 420 WPL6 is to be used.
The vessel is required to be postweld heat treated.
There are no requirements to follow other that ASME (That is client specification says "All presure vessel shall be designd and fabricated to ASME Sec VIII Div 1 as per desin data (Design data given)
Question 1:: Noting that ASME Sec VIII Div 1 UCS does not call for simulation heat treatment for P1 material, yet as per the clause 7.4 of SA 420 WPL 6 (As embedded below)Is it necessary (In order to meet the ASME requirement) for the vessel manufacturer to inform the fitting supplier that the vessel is going to be used in a vessel and that the vessel is going to be post weld heat treated and the fitting need simulation heat treatment?
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.
Question 2) Does the words " When specified so" imply an obligation on the part of vessel manufacturer to inform the manufacturer of the fitting?
Question 3) IF the vessel manufactuer does mention the vessel is being heat treated, is it mandatory for the fitting manufacturer to subject the test specimens to the same post-weld heat treatment prior to testing (Even if the vessel manufacturer does not call for Simulated testing).
The vessel is required to be postweld heat treated.
There are no requirements to follow other that ASME (That is client specification says "All presure vessel shall be designd and fabricated to ASME Sec VIII Div 1 as per desin data (Design data given)
Question 1:: Noting that ASME Sec VIII Div 1 UCS does not call for simulation heat treatment for P1 material, yet as per the clause 7.4 of SA 420 WPL 6 (As embedded below)Is it necessary (In order to meet the ASME requirement) for the vessel manufacturer to inform the fitting supplier that the vessel is going to be used in a vessel and that the vessel is going to be post weld heat treated and the fitting need simulation heat treatment?
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.
Question 2) Does the words " When specified so" imply an obligation on the part of vessel manufacturer to inform the manufacturer of the fitting?
Question 3) IF the vessel manufactuer does mention the vessel is being heat treated, is it mandatory for the fitting manufacturer to subject the test specimens to the same post-weld heat treatment prior to testing (Even if the vessel manufacturer does not call for Simulated testing).





RE: SA 420 WPL6 in U stamped Pressure vessel
RE: SA 420 WPL6 in U stamped Pressure vessel
We have had to run tests on fittings with multiple heat treat cycles for our client.
RE: SA 420 WPL6 in U stamped Pressure vessel
Regards,
Mike
RE: SA 420 WPL6 in U stamped Pressure vessel
RE: SA 420 WPL6 in U stamped Pressure vessel
Regards,
Mike
RE: SA 420 WPL6 in U stamped Pressure vessel
But our client's inspector, seem to have a different point of view. While he is an expert in his own right and we respect his knowledge, in this instance, we believe he is flawed by insisting the application of clause SA 420 WPL 6 and calling Simulation testing.
Metengr::
We are construction/Vessel fabrication contractors.
Client places order on us for pressure vessel and provided us with the dsign data. MDMT is -40 Deg C. We procure the material and construct the vessel.
We had placed 2 orders for fittings (Due to delivery constraints)
order 1 on a local trader (Standard SA 420 WPL6), we never mentioned any thing about the PWHT or simulation testing in the order. The trader had stock (SA 420 WPL6 2005 year manufacture)
The certificate that the trader has provides results in N and T condition and also in N & T + 595 Deg C PWHT cycle.
Here there was no issue since the certificate caters to both the simulated and un-simulated condition.
order 2 on manufacturer (From Italy), here again we did not mention any thing regarding PWHT or simulation, just standard SA 420 WPL 6.
The manufacturer provided certificate with the test result only in N and T (Supply condition).
Now prior to PWHT while reviewing the Material certificates (by the client inspector) he has made the observation that the fittings are to have simulated test results (Sighting SA 420 WPL 6 clause).
RE: SA 420 WPL6 in U stamped Pressure vessel
Also, because these wrought fittings are specifically mentioned for low temperature service, PWHT may have an adverse effect on notch toughness. Your client's Inspector is correct regarding PWHT time cycle in SA 420, and this should have been specified at the time the order was placed.
RE: SA 420 WPL6 in U stamped Pressure vessel
Steve Jones
Materials & Corrosion Engineer
http://www.linkedin.com/pub/8/83b/b04
RE: SA 420 WPL6 in U stamped Pressure vessel
While the customer may not always be right, he IS always the customer:)
Regards,
Mike
RE: SA 420 WPL6 in U stamped Pressure vessel
Normally, you are spot on with your posts. In this case because of the effects of PWHT on notch toughness behavior, I would not consider these as standard fittings that would be exempt under UCS-85 (e). Also, as stated in SA 420, the PWHT cycle clause (if applicable) must be fulfilled. All requirements of the SA specification must be met, regardless.
RE: SA 420 WPL6 in U stamped Pressure vessel
Regards,
Mike