Ball Valve Seat of Pigged Pipeline

[Weko]

Dear All,

What is the best design for a pigged trunnion Full bore ball valve design. The valve is attached to the pig launcher and pig receiver (to isolate between the pig and the pipeline)

1. Soft seat vs metal seat?
2. Single piston effect vs double piston effect?
3. Any other special design required? i/e by pas valve, cavity relief etc?


Regards,
Weko A

 

[zdas04]

When I owned those standards for onshore US, that design would not have passed the "are you freaking serious" test. That is onshore US prior to 2003. Not yet fully infected by the North Sea/North Slope/Deep Gulf malaise that has infected the corporation today.

David Simpson, PE
MuleShoe Engineering

Law is the common force organized to act as an obstacle of injustice Frédéric Bastiat

 

[BigInch]

I think I can trace the development from the North Sea, copied by some Arabian Gulf operators (Not Saudi Aramco), mostly those closely affiliated with BP and Shell, ADCO and PDO. It was copied around the internet (National Iranian Gas Co. had downloads on the net that they had ripped from BP. Then picked up by Indian engineering community. Now they may be making inroads in SE Asia, not sure. Interestingly enough a large, hi press, relatively recent 2007, onshore gas pipeline in the UK, Milford Haven Gas Pipeline

http://en.wikipedia.org/wiki/South_Wales_Gas_Pipeline

was I think designed by National Grid staff engineers, does not use doubled valves on traps, so it has not gone completely full circle ...yet.

I hate Windowz 8!!!!

 

[BigInch]

I think I'd reverse the position of the check and block valve on the purge line, so no gas is perpetually trapped between a pressurized check valve and the block.

I hate Windowz 8!!!!