In service welding.

[Joss10]

To apply the recommendations in API 1104 - APP B - In service welding, it is mandatory that the fluid (oil, gas) must be flowing.
The problem we see is that applying welding on the outer surface without oil / gas fluid circulating inside the pipe, acting as a coolant / heat sink, could generate some type of fire / ignition / explosion inside the pipeline.
That is the reason we are looking for similar information and as warm as API 1104 - APP B, but without circulating fluid.
Any comment is grateful in advance.

 

[mk3223]

As stated in the App.B, there is a concern of the burning through during the in-service welding. To maintain a flow in line is to reduce heat accumulated during welding, and to minimized the risk of burning through. On the other hand, it should avoid the high flow rate, so it won't be cooled too fast.