Divertible Piggable Wye "Y" Fittings

[rfartash]

For an offshore project we have plenty of pig receiver and launchers (totally 13 EA) and we are doing some optimization to reduce the QTY of the launchers and receivers because of the space limitations.

I came across to divertible or bi-directional or pig switches and I am curious to know some more details regarding these items.

See below links:
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http://www.oceaneering.com/oceandoc...PRS - Bi-Directional Piggable Wye Fitting.pdf

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http://www.qcsww.com/QCS_DualDirector-sm.pdf

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http://www.oilstates.com/fw/main/Piggable-Y-Fitting-459.html

We want them for sizes 8inch, 10inch and 12inch for pressure rating of #2500.

Can anybody provide me some more data about their mechanisms, application and cost indication?
Do we have any other manufacturers?

Roozbeh

 

[zdas04]

You really have to decide what functionality you need. If the shutoff is important, then either of the first two provide that. If you are just trying to have multiple launchers share a receiver then the last one makes all kinds of sense. I've always designed my own to incorporate liquid-removal coincident with bringing the lines together (since the two streams act on each other in the fitting and do a good job of separating the water from the gas). I've put out a dozen or so of these "piggable drips" and never had a problem with pigs getting stuck in them. I'd say that these Wye fittings have a good chance of success, but I've never used them.

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.

 

[rfartash]

Let me make my case more clear.

I want to use one Launcher for 2 lines. Then I need a device to guide the pig to each of the lines.
For my client, shutoff is important; but if these wye piece cannot provide shutoff, then I should add another isolation valve as well.

Do you have any solution?

 

[zdas04]

That has all kinds of hair on it, but either of the first two would do it. I guess you build a manifold on the platform to either send the line to a barred tee downstream of the Wye or through the launcher. I can picture how I would do it, but drawing the piping up is more than I can do for free.

An alternative you might want to look at is pigging valves. These guys would take a lot less room than even your sharing option (they take the same room as a ball valve). I've always thought Argus Pigging Valves (take a look at the video at the bottom of the page) that the 8-inch valve was too expensive, but compared to the price of real estate on a platform they are really cheep. Argus has 8, 10, and 12 inch valves (the designs bigger than 8-inch are new and I've never used them) and they say "contact manufacturer for ANSI class greater than 600. It looks like they can build you ANSI 1500 (good to 3700 psig). If you need ANSI 2500, I bet they can provide it with a bit of lead time.

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.