Should the two isolation valves fot the pig barrel be DB&B valve? If yes, does any code state th
Should the two isolation valves fot the pig barrel be DB&B valve? If yes, does any code state th
(OP)
I am working at an EPC firm. Just found some project use DBB ball valves for the isolation of pig barrel, and some project just use regular ball valves. I want know if this is regulated by any code or just by the client preference.
The pig launcher or receiver can see this link:
http://www.act-on.ca/acton/Product/pig_launching_&...
The pig launcher or receiver can see this link:
http://www.act-on.ca/acton/Product/pig_launching_&...





RE: Should the two isolation valves fot the pig barrel be DB&B valve? If yes, does any code state th
RE: Should the two isolation valves fot the pig barrel be DB&B valve? If yes, does any code state th
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.
RE: Should the two isolation valves fot the pig barrel be DB&B valve? If yes, does any code state th
Carl
RE: Should the two isolation valves fot the pig barrel be DB&B valve? If yes, does any code state th
Other valves are sometimes used for pig barrel isolation: special plug valves and slab gates come to mind. These are not always DBB.
A lot of the gas we deal with is pretty sour and it doesn't take much of a leak across a valve to knock you down; but by that argument, the gas will be coming out the "bleed" anyway, and the Operator won't be more than ten feet away from it.
The most common arrangement that I have seen is a single DBB ball valve; whenther or not it is a trunnion or a floater ends up having as much to do with line size and pressure as with the DBB function.
RE: Should the two isolation valves fot the pig barrel be DB&B valve? If yes, does any code state th
Nothing I have ever said about DBB or pig launchers/receivers applies to your situation. I visited a plant outside of Calgary once and was amazed at the mountains of sulfur that used to be H2S. If I had pigging facilities on sour gas lines, the OSHA regulations would be the least of my considerations. It seems that everything an Engineer does in that stuff should have very careful consideration and checking, I'm really scared of that stuff.
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.
RE: Should the two isolation valves fot the pig barrel be DB&B valve? If yes, does any code state th
Would that plant you visited have been Crossfield or Lone Pine Creek, by any chance?
In the '80s, just about every gas plant in central and southern Alberta blocked sulphur and subsequently remelted the blocks for truck and rail transportation. The view from the air looked like some gigantic child had tossed his yellow alphabet blocks all across the Province.
Agreeing with you, sour gas pig barrels and their operation are probably among the most risky pieces of equipment Operators face. Our typical sour gas composition, when sour, ranges from 10% to 35% H2S-in-gas (i.e., 100,000 ppm to 350,000 ppm). Probably the most dicey operation in these pipeline gathering systems occurs when people are trying to dislodge and move a hydrate plug through a section of line, creating an instant oilfield potato cannon effect. I have even heard of some folks who open up the closure, park a D-9 Caterpillar with blade at the now open end of the barrel, and open the pipeline isolation valve. To their credit, they *did* use a D-9, as opposed to something smaller.
RE: Should the two isolation valves fot the pig barrel be DB&B valve? If yes, does any code state th
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.
RE: Should the two isolation valves fot the pig barrel be DB&B valve? If yes, does any code state th
The latest API 6D spec defines the differences between these designations very clearly for anyone who will take the time to read it.
RE: Should the two isolation valves fot the pig barrel be DB&B valve? If yes, does any code state th
Independent events are seldomly independent.
RE: Should the two isolation valves fot the pig barrel be DB&B valve? If yes, does any code state th
These DBB comply to ANSI B16.10 Face to Face Sizes while providing double-block-bleed. Apparently, Oliver Valves has a DBB pig launcher and receing system which has minimal foot print.
Regards,
Aamir
RE: Should the two isolation valves fot the pig barrel be DB&B valve? If yes, does any code state th
Every one of those I've ever seen has had reduced port valves in the body--not good for pigging. I've also seen a few that had the ball offset from the centerline to reduce space--again not very desirable for pigigng.
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.
RE: Should the two isolation valves fot the pig barrel be DB&B valve? If yes, does any code state th
These are true full bore and ball are inline for pigging applications.
I guess sizes are limited to 8" 2500# full bore with manufacturer.
I can send some literature , if u wish!!
Regards,
Aamir