Minimum distance from weld joint of riser bend (buried) to buried flange

[RNZaman]

It would be much appreciated if anyone can suggest me the minimum distance to be maintained for a buried section of pipeline from riser bend weld joint to a flange weld joint. The flange to be connected to a flanged valve.

 

[1503-44]

Pipe diameter might be good to know, right? As well as a sketch. There is no standard configuration for these things.

A black swan to a turkey is a white swan to the butcher ... and to Boeing.

 

[LittleInch]

You could weld the flange right onto the end of the bend if you want to. Usually not a great idea, but nothing to stop you.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[1503-44]

I try to avoid flanges and isolation joints, or isolation blocks anywhere near the riser. The riser is one of the places on a pipeline where stresses are usually maximum. A joint of distance away is usually much better, unless that puts you near an anchor block.

A black swan to a turkey is a white swan to the butcher ... and to Boeing.

 

[GD2]

RNZaman,

It is advisable to have adjacent weld joints at 100 mm distance to avoid overlap of HAZ.
if you are using a transition piece, it should be minimum 300 mm long.
As long as you make the above ground weld joint in the tangent of the riser bend, you should be ok.

GDD
Canada