API 5L X70 Pipe

Date 01-02-2008 20:07

I am getting ready to accept or not accept a job where we are welding X70 pipe. I am not familiar with this material. I have experience with X65 pipe, but not X70. Can you guys tell me if there is anything I need to be aware of when welding this material?

I really appreciate everyones input in advance. Thanks

By dbigkahunna (****)

Date 01-02-2008 23:52

What size?
If you are welding where it is cold, then you will have to pre-heat to 200F at every joint and again if it falls below 100 depending on the customer specifications.
Keep the heat low on the bead and limit travel speed on the bead to 12 ipm max.
Do not move the pipe until the hot pass is laid.
Arc burns are a no-no anywhere.
Bout all I know
BABRt's

By chall

Date 01-03-2008 15:34

It is in the "third category" of materials discussed in 1104. It is one that requires a separate PQR for the WPS (greater than or equal to X65 requires a separate qual for each material).

We did some research into X70 a few years ago. Frankly, I didn't find it too difficult (from the engineering standpoint). As stated by bigkahuna, preheat is generally higher than normal, but will probably be specified by the owner; and arc strikes are a serious issue.

Because of the strength, low temperature application and the alloying of the material, owners are usually very cautious with X70. We were able to satisfy all PQR requirements (and additional testing such as Vickers and charpy) but the owner refused to allow us to use the FCAW process. They were simply not comfortable with the process. This was a few years ago, and I know that others have been successful with it; but each owner has their own set of guidelines.

Charles