BIDIRECTIONAL PIG TRAP

[chitessy]

Hi All,

I have a challenge in designing a Bidrectional pig trap. Designing a pig launcher only or pig receiver only is not a problem. But for a pig trap to serve as a launcher and the same time as a receiver( bidirectional) is a big challenge, considering position of the kicker line, length of major and minor barrel, type of valves, number of valves to install etc.

Please, is there anyone out there that have design a bidirectional pig trap, i will appreciate your advice, reference material and if possible sample template of the bidirectional pig trap.

Thanks very much for all your support.

Chitessy

 

[RandomAxe]

Have you tried googling 'Pig Launcher/Receiver'? I've come across them several times, sometimes they are referred to as PLR's, so you could try searching with that as well. I don't think they are that rare.

 

[RandomAxe]

http://www.oceaneering.com/oceandocuments/brochures/dts/DTS - Pig Launcher & Receiver (PLR).pdf

 

[zdas04]

Every single launcher/receiver I design is bidirectional. I've had marketing make too many deals that change direction in a line when they find a new market. The only real difference between a launcher and a receiver is the location of the pig signal.

I've attached a drawing of the launcher/receiver I've evolved to. The last innovation was the flange that is near the closure. This allows you to drop in a spool piece to extend the barrel for smart pigs. The receiver (on the left in the drawing) has the drain connected to a sump, the launcher just has a drain valve. Both units have a boss for a pig signal on either side of the barrel isolation valve so you can put in two pig sigs or move it. There really is no need to put the kicker/bypass line in different places for a launcher than a receiver, and the throat length (what you call the "minor diameter") can easily be the same.

David Simpson, PE
MuleShoe Engineering

"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
The plural of anecdote is not "data"

 

[LittleInch]

Chitessy, you really don't have a problem. Just design as for a receiver, but put the kicker line in the middle and make it flat. I'm with David all the way and have been preaching the same message for some time, i.e. just make all pig traps the same and FLAT. A lot of operators now only have a flanged set of valves and only bolt up the traps when they need them so it's easier to have them all the same.

Use not seen the flange with extension piece before, but looks like a good idea, just make sure you leave enough room for everything. Personally I don't go much for pig sigs but if you like them just put them on the minor barrel and the other side of the tee.

The very best thing you can do is make sure you specify a decent end closure and don't just take the cheapest you can find.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[chitessy]

Thanks all for the advice, am almost done with my design work.

I sincerely appreciate all your inputs

Thanks All

Chitessy