Power failure during PWHT

[Ratheesh_n]

Dear Team,

Power failure happened during heating cycle of PWHT of APL 5L X65 welds ( piping as per B31.3).understand there is no issue in re-doing the PWHT as the crystal transformation temperature is not reached.

1). Does this interruption will have any impact on metallurgy ?

2). What is the impact if Interruption happened during soaking time and what is the recommendation as per ASME B31.3 standards.

Note:- WPS is qualified considered 2 repair (i.e two heat treatment cycle).

 

[weldstan]

So, did interuption occur during soak or during heating? I've simply repeated the established PWHT cycle when such expperience s occurred.

 

Cases:

1) Interruption heating: basically no PWHT has happened >> start over.
2) Interruption during soak: note the soak time before interruption, then repeat the heat treatment such that total soak time equals the original planned time.
3) Interruption during cooling: PWHT was successful.

The only condition that might violate Code rules is if the allowable cooling rate was exceeded. I believe the AI would be understanding that with a simple configuration like a pipe joint, there are no structural consequences (which is the logic behind heating and cooling rate limits). This gets trickier for more complex configurations.

These guidelines would apply to all ASME construction codes.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[Ratheesh_n]

@ weldstan,

Interruption happened during heating cycle.

 

[weldstan]

See ironic metallurgist reply N0. 1.