pig trap valves

[pipeliner3000]

Looking at valves (ball) for a pig trap and thinking DPE (one side only)for pig trap isolation valve giving double block isolation. Thinking similar for pig trap bypass valve but maybe DPE both sides as pressure coming from both sides - any ideas?

 

[zdas04]

Why do you need double block isolation? If you have to weld inside the barrel, you can set a foreman plug to get a second barrier. I tend to use the cheapest full-port valve I can find for a barrel-isolation valve. I also put a vent in the throat very close to the barrel-isolation valve so if the valve leaks, I can open the vent and still load a pig (it is really annoying to shove a pig into the throat and have valve leakage push it out before the barrel is purged).

I always ask "why is this valve here?", and what is the most life-cycle cost-effective valve to put here?". The answers to both of those questions tend to be standard, full port, trunnion ball valves for barrel isolation valves.

If you have a reason that makes sense to you to go above and beyond, remember that to get DB&B you have to do something with both the barrel-isolation valve and the kicker valve--people tend to forget the kicker.


David

 

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