Low temperature pipe line

[purode333]

Dear sir,

As all of you knows that in high temperature application piping, we used heat tracing below insulation to maintained the heat or to avoid the heat loss.

I want to know that in low temperature application piping line, what to do ? (in place of heat tracing)below cold insulation(PUF) to maintained the low temperature or to avoid the freezing.


Regards
Prasad

 

[XL83NL]

To avoid freezing, we use winterizing; a fancy name for heat tracing. It's the opposite of maintaining the low temperature.

 

[LittleInch]

Good question.

I've not seen any mechanism used on system to maintain a low temperature.

It normally means relatively short pipelines, keeping flow going through them back to the cold storage tank (that's what they do with LNG) where the boil off keeps the temperature low.

Or if you have say low temp LPG, you allow for the fact that the liquid could heat up and increase the pressure rating accordingly so that whatever pressure it is at at ambient conditions, your pipe can cope with that whilst keeping the product in a liquid form.

I guess you could use some form of tubing / piping under the PUF with refrigerant / cold liquid or run a pipe in pipe in pipe with cold liquid in the middle annulus.

All depends how important it is to keep the stuff cold at all times, flowing or otherwise.

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

 

[EdStainless]

For cryogenic applications you see double walled pipe systems with a vacuum between them for more efficient insulation.

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P.E. Metallurgy, Plymouth Tube

 

[Compositepro]

The question is ambiguously worded, please make it clear. You say low temperature piping and to avoid freezing. Is this cryogenic, or does low temperature mean not high temperature but needs heat to avoid freezing? Or do you mean to prevent icing on the outside?

 

[georgeverghese]

Insulation in low temp applications can lose effectiveness when insulation becomes damp. Repair the insulation and the aluminum jacket so rainwater cannot seep in.