Pipe insulation

[Missy M]

For those of you who live way north. If you were going to insulate an outdoor water pipe what would be the best type of insulation for this. Something that would be effective in extreme temps. Possibly to be used in conjunction with a heat tape.

[highlands]

Drip.
Tube ins.

[Harry Chickpea]

Grew up a bit north of where Highlands lives in Vermont. The best insulation is four feet of earth. The frost line reaches four feet down in some places. The only exposed water piping I saw there were the 4' diameter flumes going to an old hydropower station on the North Branch of the Winooski.

[Missy M]

This is for industrial. Drip and below ground are not options. Covering with insulation is the only option. I just wanted to know what type would be best.

[Darren]

Build an insulated box around it with a heat source inside. Include an access door so you can repair/replace what ever you use for heat. If you want to get fancy use one of those temperature sensors that uses a radio transmitter to display the temperature inside on the readout.

[simi-steading]

If you can't do like Darren said, the best kind is the fiberglass pipe insulators with either foil or plastic around it..

[fishhead]

If I were to insulate an exposed water line I would box it in with 2" foam board. Cut it into strips that can be built into a square tube. I did that with my water line running from the well to the house. Some PL 300 will glue it together. You could leave one side unglued so that the tube can be removed during summer to protect it from the sun and just duct tape that piece in place during the winter.

[Fire-Man]

Originally Posted by Missy M

This is for industrial. Drip and below ground are not options. Covering with insulation is the only option. I just wanted to know what type would be best.

Missy, No insulation will stop water from freezing unless their is a heat source. Insulating a pipe without some form of heat will only delay the freezing a little and will ALSO delay the thawing after the outside temp gets above freezing.

Heat sources
Can be the ground, if you live in a area that does not freeze below the dirt very much--I turn a 5 gallon cooler over a low wrapped outside spigot--works good here. Enough heat rises from the ground to keep it from freezing.
Electric heat wraps/tape etc.

Moving water(dripping) brings the heat from the unfrozen ground up the pipe to keep it from freezing. If there is no heat source even running water will freeze(do a search on frozen waterfalls).


Example---Try this, go get you a whole roll of insulation from Lowes, cut you a slit in the plastic, stick a pack of unfrozen meat in it. Now put it in a freezer---take it back out in a few days----it will be froze---No heat source.

Now to the heat tape with insulation. Wrap your outside spigot with the heat tape from the top down below your frost line, then wrap it with alot of pipe insulation/or insulation, then put something over this to keep the insulation from getting wet, big enough that it does not compress all the insulation. Can be a big enough piece of pvc pipe with a cap on top or a barrel or similiar. Oh Plug the heat tape in. Good Luck!

[Callieslamb]

Is it a pipe or a hydrant? If you live in an area with an exposed water line that isn't underground far enough to keep it from freezing in your type of cold, it's time to change the water line.

We've been at -14 here. I have a frost-free hydrant in my garden that isn't frozen. I still use it to water in the greenhouse. Other faucets are outside, but the pipes are inside a building with a heat source. I think your best bet is to build the already mentioned box around it and put a heat lamp inside.

[Harry Chickpea]

OK, if it is for industrial, something can be done but it will be an ongoing expense. You don't mention the size of the line, length, % of time used, ambient water temp, ambient air temp that you need to protect again, etc.

I will reiterate though that in cold climates NOBODY does anything like this. Experience is a hard teacher.

If you use heat tape, use two. That way if one fails, you don't have a frozen line.

Soft copper piping would probably be best, because I'm going to suggest a second pair of smaller copper lines as outrunners tied and spot soldered to it as a more robust system. It would run a heated loop of antifreeze with the antifreeze liquid heated by a small water heater and run through a pump. The lines would then be insulated as a bundle with closed cell foam and boxed in a trough as described in another post.

To keep ongoing expense down, the heater and pump for the antifreeze would have to have a power thermostat that only powered it on if outside temps fell to 40 degrees.

An alternative is to do like I do. We use a cistern and pump water up from the creek. I only pump to fill on days above freezing and do not use a foot valve, so the system is dry when the temperatures are below freezing. This week is a challenge because Sunday afternoon will be the only day for a while that I can start a refill, but the system is MUCH simpler and less costly than alternatives.

[SolarGary]

Hi,
If the water use is intermittent, you might try arranging the plumbing such that after each demand the water drains out of the pipe. This would require a value like the ones on the frost free hydrants that drain the part of the hydrant that extends above the ground whenever the water is turned off.

The line would have to have some slope to it in order to drain.

Another possibility would be to plumb it like drain back solar heating systems. When the pump is turned on, water circulates to the solar collectors to pick up heat, and when the pump turns off, the plumbing is arranged such that all the water in the collectors and outside plumbing drains back to the tank. This works at -30F for me.

Gary