when 3 cycles for simulated heat treatment are required?

[manj1987]

Due to Sour service in one equipment i am working on, PWHT is required, secondly heads need to be normalized also . material of the vessel is SA 516 Gr 70 normalized and impact test also required. In this case do we need to inform mill to perform 3 cycles for simulated heat treatment??

 

[SnTMan]

In my experience it unusual to ask for any simulated PWHT on P1, G1 & G2 materials. Sec VIII Div 1 does not require it.

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[manj1987]

Actually in Aramco standard following in written, so in the light of below requirement from client,heat cycles need to be performed??

12.1.9 Materials of construction (pressure-retaining parts of vessel and non-pressure retaining attachments) shall be tested to verify that their mechanical properties (strength, toughness, creep-resistance, etc.) will be retained, considering all of the following thermal treatments that could affect the material:
a) All heat treatment cycles that will be required for the fabrication of the vessel, including as applicable: normalizing, normalizing and tempering, quenching and tempering, intermediate stress relief (ISR), and final postweld heat treatment (PWHT),
b) Two PWHT cycles to account for future repairs and/or alterations.

 

[viper3982]

Not unusual for Aramco. We usually end up just giving them a cost adder and perform 3 PWHT with lab testing at their cost.

It's a customer spec. If they want to pay for it...

 

[SnTMan]

If client requires it, that's different. I'd say you need at least three, one for fab, two for FIELD repair. In my experience you do not allow one cycle for normalizing the heads.

You may want to add one for any potential SHOP repair. Creep resistance? Good luck.

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[Trestala]

Shell has a similar requirement, but it refers to three PWHT cycles applied to production test plates, not materials procured from the mill.