Hot Pig?

[donf]

I have an underground pipeline in which the contents may be frozen. Not at liberty to divulge the contents, but product starts to gel at 50F. Pipe size is NPS 3. Length in excess of two miles.

I know very little about pigging. Does anyone know if there's such a thing as a heated pig? I could install launching/receiving stations. 316SS would be acceptable material of construction for the pig.

Thank you for your time.

donf

 

[BigInch]

Sounds like now is the time to add heat tracing.

 

[zdas04]

A pig can be anything you want it to be. You can run a tethered pig with an electric line and a resistance element on the front. Big question is what are you going to push it with? If you have that worked out you could cobble something together by summer. Oh yeah, by summer you won't still have the problem, but you'll have the solution for next winter.

There is nothing off the shelf that I've ever heard of.

David Simpson, PE
MuleShoe Engineering

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist

 

[LittleInch]

In a word, no.Even if there was, I can't see how this would help you.r There are many issues here but normally insulation and trade heating are your first points of call.

A few more details would help, any insulation?, temp in and out, constant flow?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[BigInch]

You might have had some success with hot water, or light oil jetting, but the tiny diameter and long length don't bode well.

 

[Latexman]

Is this secret contents compatible with water/steam? If so, and the isometric layout is conducive, from both sides and all points in between that you can afford - steam on, steam off, drain/pump out, repeat.

This worked a couple times for me with PTBP (m.p. 100^o C), but the isometric layout was more favorable and the line a lot shorter than yours. It was up in a pipe rack, not down in the ground. You will have to pump the condensate out. Mine took less than an 8 hour shift. I expect you are looking at days, maybe weeks.

If the pipe is above the frost line, don't try this.

Good luck,
Latexman

Technically, the glass is always full - 1/2 air and 1/2 water.

 

[MortenA]

A couple of suggestions in another directtion: You can get a lab to test the yield strength of the gel (how much force it will take to mobilise it, and then check if the required pressure in your actual pipeline is below your design pressure. They can also test if your gel has a tendency to break (many gels will since the gel has a higher density than the liquid and voids thus forms and breaks the gel.

Best regards, Morten

 

[racookpe1978]

Too bad you can't run the heat trace line inside the pipe, but have to wrap it around the outside of the pipe. If it were inside, you could use the reinforced heat trace line to slowly pull a narrow pig through the pipe through the gel. 8<)

Steam heat tracing would be much too hard over than distance, compared to simple electric exterior wrap under the insulation, right?

 

[MikeHalloran]

Ground one end.
Hook an arc welder to the other end.
Start the welder.
See if you can pump a couple hundred amps through the length of the pipe.
If you're lucky on several fronts, that will warm it up.

If that doesn't work, insulate and heat trace the new pipe.

Mike Halloran
Pembroke Pines, FL, USA

 

[donf]

To all who responded - thank you very much, and again - sorry for the lack of details. I've been a member of this forum long enough to know that the better the situation/problem is described, the better the response.

Turns out that the problem had to do with the failure of the heat tracing controls. Situation under control.

Again, thank you.

donf

 

[BigInch]

Good for you. Pigging that little line wouldn't be any fun at all.