LENGTH OF PIG TRAP MAJOR AND MINOR BARREL
LENGTH OF PIG TRAP MAJOR AND MINOR BARREL
(OP)
Hi, everyone,
please, i want to know if there is a standard length of major and minor barrel of a pig trap of a particular line size.
your advice would be appreciated.
please, i want to know if there is a standard length of major and minor barrel of a pig trap of a particular line size.
your advice would be appreciated.





RE: LENGTH OF PIG TRAP MAJOR AND MINOR BARREL
RE: LENGTH OF PIG TRAP MAJOR AND MINOR BARREL
That being said, I think the dimensions of the traps in CRG's reference are wrong for today's requirements. I've never liked their launcher not having a minor barrel to speak of, the concentric reducer is just dumb, and the major barrel is pretty short.
My rule of thumb is to make the barrel about as long in feet as the nominal pipe diameter is in inches (i.e. a launcher or receiver on a 6-inch line would have the major barrel 6 ft long). I like to set the launch tube (minor barrel) at 4D (24 inches on a 6-inch line). These dimensions let you launch most smart pigs without having to kludge on an auxillary barrel.
If you're rolling your own pig-trap designs, spend some time thinking about kicker and bypass line sizing. I've worked up some sizing that satisfies most client's maximum pressure drop requirements. The numbers are on my web site under "Samples" as Rules of Thumb for Gathering Systems. That might give you some direction.
David Simpson, PE
MuleShoe Engineering
www.muleshoe-eng.com
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
The harder I work, the luckier I seem
RE: LENGTH OF PIG TRAP MAJOR AND MINOR BARREL
RE: LENGTH OF PIG TRAP MAJOR AND MINOR BARREL
I'd recommend designing for and intelligent pig just in case, and contacting the all intelligent pigging companies for their current pig dimensions and designing off the longest one for the major barrel length as future intelligent pigs will almost certainly get shorter rather than longer.
I've also seen shorter minor barrels on the reciever and longer minor barrels on the launcher, but I don't have much operational pigging experience to be able to say if this kind of thing is good, bad or neutral.