Pig launcher & receiver design...

[11echo]

I'm working on a pigging system for a 16" water injection line, this is a ANSI class 600# system. My question is this, what is the rule for sizing the barrel(s) for the launcher & receiver (NOTE - we are only using foam pigs in this line). What I've seen is the barrel is only one size larger then line size, just to facilitate getting the pig loaded up and for ease of launching. But I have another engineer telling me it should be 2 sizes larger because of size. Seems to me this is unnecessary, it would be abit more expensive and not as effective in the launching mode. Anybody "know" or can point me where to look to be sure? THX! ...Mark

 

[hydrodude]

I have never seen a launcher mor than one size larger and as you say if it is too large you won't get a good seal to launch. One size will work for squeegee, hard foam, poly or smart pigs

 

[Nosey]

I've just had a look at the pigging design manual for a major oil company and it states that the barrel of the launcher should be 2" greater than that of the pipeline for pipeline diameters up to 20". For pipelines equal to or over 20" in diameter the barrel should be 4" larger.

So, for a 16" NB pipeline I'd expect to see a 18" barrel. This ties in with your initial statement of one size larger.

Hope this helps.

Regards

Nosey

 

[Hookem]

In natural gas and liquid hydrocarbon pipelines, we always use 2 sizes larger.