Pigging Ball Valves

[MarkCA]

I'm working on a job where the client wants to use ball valves in a pipeline but prefers soft seats, i.e. PTFE. My boss on the other hand is unsure whether or not this is allowable when this line is going to be pigged. He's worried the pig will damage the seats.

Now I recall a conversation with the project regarding this and they mentioned plans to use soft pigs, styrofoam I think, but he doesn't remember this.

Which brings me to my questions: 1) am I correct that a soft seat ball valve can be piggable using an appropriate pig and 2) where can I go (preferably code or manufacturere literature) to verify and document this for my boss?

Thanks,
Mark

 

[pennpiper]

Step 1. Find out what kind of "Pigs" will be used and for what purpose.

Step 2. Contact the Ball Valve Vendor and discuss the above information with them. Have them define if they can warranty their valve for the conditions defined.

 

[MarkCA]

So the short answer is, "Yes"?

The long answer is, "Maybe, it depends"?

 

[pennpiper]

That is correct on all points.

Good luck.

 

[belowzero]

The reason a pig can be used on a ball valve is that the soft seats do not actually go right to the edge of the ball, therefore when the pig passes through hard or soft the seats are unaffected in the open position. Obviously only True Full Bore valves can be used.
My previous companies have fitted these into toothpaste lines when changing colours, so have many oil companies.
Although I know Jamesbury have valves such as launchers and thier Full bore valves will do the job, take a look at this link, they specialise in this area and use Ball valves.

http://www.argusmachine.com/pigging-valves.cfm

B

 

[belowzero]

and I don't mean oil companies use toothpaste!!
B

 

[zdas04]

Get a valve like you are wanting to use and drop it on your boss's desk and ask him to show you where any pig would touch any sealing surface. I use ball valves exclusively in launcher/receiver designs and have run some very agressive brush pigs with no damage to the valves at all.

Simply fear and superstition.

David

 

[MarkCA]

I was able to speak with one of our vendors and he said that all full port, API 6D ball valves are piggable regardless of seating material.

Thanks for the help.