Hardness Test after PWHT

[Yash Patel]

Hello,
I have to send all the BW joint CS/SS pipes (thickness is less than 3/4") for PWHT. The code says PWHT is not required if the thickness is below 3/4", but it's client requirement so have to do it.
Can anyone tell me how much hardness is required for testing? the services are Sour Gas and Amine.

 

[UDDBOY]

Each material Hardness is determined. When you PWHT it The effect on hardness and the hardness depends on the cooling rate.
When you PWHT it, you must check the hardness to make sure it is in the correct.

 

[david339933]

In my experience Amine service usually follows NACE MR0103, which mandates SP0472. SP0472 states weld deposit hardness shall be controlled to 200HBW. There are exemptions to production hardness testing in SP0472, but if you are definitely hardness testing CS welds, that's what you should be below.

 

[david339933]

Forgot to mention that newer editions of piping codes (B31.1/B31.3) no longer have mandatory PWHT for P1 materials....as long as you preheat to 200F if thickness is over 1".

 

[Yash Patel]

David, does SP0472 states that the welds have to go for hardness test even though the thickness of the pipe is less than 3/4"?

 

[metengr]

Why don't you ask the client for this information? If they are requiring it they should have this information.

 

[Yash Patel]

We have PWHT requirement stating 1150F for 60 mins. Is there a typical cycle for PWHT in code with rising and falling rates which have to be followed while heat treating? something like
"Ambient to 600F at moderate rate
600F to 1150F at 400F/ hour
Hold 1150F +/- 25F for 60 mins
Cool to 600F at 400F/hr"

 

[Yash Patel]

sorry didn't mention earlier, the material is Carbon Steel SA-106 Gr.B

 

[metengr]

Several of the ASME piping codes contain requirements for heating and cooling ramp rates based on pipe wall thickness. Please refer to your code of construction.

 

[mk3223]

For reference, the PWHT requirement for the CS (P1) piping may be based on the pipe thickness per AMSE B31.3, i.e. >3/4" WT (2012 or earlier) or >1" WT (2014 or later), or depended on the services condition which may apply to all pipe thicknesses, such as Amine, caustic, Carbonate, Anhydrous Ammonia services, etc. You may want to confirm with the Client for a specific Code as required to be followed.

 

[Chumpes]

metengr is rigth, those who ask for PWHT and hardness limitation shall provide the targeted values