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Pre-Launching inspection
2

Pre-Launching inspection

Pre-Launching inspection

(OP)
Please guys will need assistance on a pre-launching inspection(steps) done prior to launching a pig. Thanks.

RE: Pre-Launching inspection

I could write chapter and verse on this, but to be honest I get worried about requests like this as pigging has one of the highest potential incident / injury operations that pipeline operaions ever sees and it needs good experience and design to get it right. It is difficult to get the operation as safe as possible without a good design, but a good design can only be as safe as the operator.

Each system is different (is it gas or liquid) and has different issues. Use of the P & ID to come up with a procedure using valve numbers is recomended using the following basic parameters.

Assuming you know how to safely de-pressurise, drain or vent your trap, with all isolations locked closed then:

Insert pig and push as hard as posisble into the neck of the trap.
Close the door and ensure full sealing
Pressurise / fill slowly, ensuring that there is piping connection (equalisation line) between the space infront of the pig and behind it
When fully pressurised / full open pig trap kicker lines fully open.
Open main valve
close main bypass valve
pig should leave trap
Have some checks, person hear / feel the pig go through the first tee / valve, pref with magnetic pig sig.
close pig trap valves, islate pig trap, de-prssurise / drain, open oddr to ensure pig has actually left....

If you can't close the main valve - maybe pig is stuck in main pig trap valve(!)

My motto: Learn something new every day

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

RE: Pre-Launching inspection

did I mis intepret this? A very good document there big bro' - I think there is something similar in a check list form on some of the pig vendors websites, especially intelligent pig (try rosen, GE etc) or http://www.ppsa-online.com/papers.php.

If you don't really know whats there then start with a flexible pig (foam), then gradually get more aggressive to check for bend radius, wall thickness change etc and run a guage then a caliper / orientation pig.

killer things are unbarred tees, <3D bends, change of diameter and internal objects (e.g. thermowells)

My motto: Learn something new every day

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

RE: Pre-Launching inspection

OK... A friend (you know him, Mike B.?) working at Corpro at the time wrote it. I really just edited it. I imagine it has made the rounds since then.

Independent events are seldomly independent.

RE: Pre-Launching inspection

Yes, I remember him. It looked a little like it had been typed, but still valid information.

My motto: Learn something new every day

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

RE: Pre-Launching inspection

Yes. We can both type. smile

Independent events are seldomly independent.

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