How do you unthaw gravity feed water system

[cliff88]

Pipe got disconnected last night near water source. I reconnected but no water flows. Pipes are full of ice in places at temp below freezing. Nothing has burst. And no risk of water damage to house. I have a drain at house so most water would have gone out the drain during the night rather than sit in pipes.
Current temp is minus 6C. Temp will be getting above freezing in next few days. I assume if the water is connected it will work its way down and create some friction. 2 inch PVC pipe is about 700 ft completely exposed to elements.

 

[jdp1152]

Tape a heating blanket around it

 

[semipro]

If this is only because of the disconnected line and restoring flow will prevent freezing I'd say you're going to have to start melting the ice out at the lower end. Starting at the low end will allow water to drain out. You could get inventive with how you heat the pipe; vehicle exhaust, torpedo heater, heat gun, heat tape etc.

If this happens regardless of maintained flow:
I have a friend with a setup similar to yours with freezing problems.
He ran a single line of electrical heat tape along the exposed (unburied) sections of pipe then placed foam pipe insulation around the pipe and heat tape.
Either the heat tape was thermostatically controlled or he just plugged it in when it got cold, can't recall.

He also previously tried heating the water at the source before it entered the pipe but the heat tape worked better.

 

[BravoWhiskey]

As suggested need some heat to start thawing. But need pressurized flow to remove the ice once a drip flow is initiated. Ideally pump water back up the pipe, or use pressurized air to open up a path.

 

[cliff88]

well ,it is frozen solid and burst in at least one place. temperatures went way down last night. temperatures going up above freezing on friday.
I guess I miscalculated by reconnecting the water . Im going to dump a bunch of salt in when it starts to unfreeze. they also have antifreeze product that
supposedly can clear long lengths of pipe.

 

[cliff88]

anybody heard of liqui fire

white pvc pipe is the pipe that carries the water. the other pipe is to hold it up.

This is the part I opened up last night. Might have accelerated the cooling of rest of pipe. Water climbed uphill and created the icicle

This black pipe with thicker casing and softer material might withstand freezing water better.

 

[Freakingstang]

as i was reading the thread i was going to reply to DO NOT reconnect water supply or you would have a mess... as I read farther......

The black pipe isn't going to work any better. it is plastic. the force of frozen water breaks cast iron car engines, tractor engines, steel pipes 1/4" thick and many many more things too.

i would not be putting it back to use without some ruggged insulation and some heat trace. Even with water flowing you are going to have issues if the temps drop enough. There is no insulation to protect it from the elements. so its -10, what is it with the 10-40mph wind chill? spit in those temps and it is froxen before it hits the ground. same principal...

another option for a cheap insurance would be to use whatever size pipe you are using, wrap it in blanket insulation and then top coat it with the next size up thin wall pipe. i would still use heat trace in the sections exposed. it will be a pita to put together but will help keeping things from freezing..

 

[semipro]

Cliff,
Do you really need a pipe that big? If not, I'd suggest you get a roll or two of 1" poly pipe and replace the whole length.

Although water flow does go a long way towards preventing freeze ups I think you're eventually going to have to insulate and maybe heat whatever pipe you go with. You never know when the flow might stop because of clogging, breakage, whatever. If the pipe is insulated and heated you'll be able to fix the problem and get flow going immediately otherwise you'll have freeze ups when the flow is interrupted.

 

[cliff88]

I talked to my neighbour this fall and he said that winters are mild enough here that I wont have problems. He has experience. I had no problems in
December and January is not much colder so I dont expect problems. The interruption in flow was a rare event and it wont cost much to repair. Very easy to repair plastic pipe. cut and glue. average low is -4 celsius and average high is .5c for january. Normally, snow does not last around here.
This system has been in place at least 100 yrs. Poly pipe and abs pipe is toxic. there is a special poly by ipex that is for water but hard to get. most
poly you see around is slowly killing the homeowner.

as far as heating, that would be pretty hard to do for quarter mile. Ive been told it doesnt help to insulate outside pipe because there is no heat to hold in.
not sure if that is correct. anyway, quite a bit of slack in system so I dont have to be completely efficient. just keep water flowing.

every situation is unique so it is hazardous to give advice on net sometimes. its quite interesting how half my line remained liquid after 2 days of very
cold weather. the water was quite brown for some reason. some of the pipe is steel. next time ill throw a ton of road salt in.

as far as internal plumbing, it is pex and survived a couple winters of no heat during foreclosure. there was water in the lines. water filter blew up. $75. toilet blew up. water heater survived. outside water tap was full of water but survived and is about 50 yrs old or more.

I do have a well 6ft deep well right beside house which has lots of water during winter. I was scrambling to get that set up until neighbour put me
straight.

 

[semipro]

Cliff,
You realize that PEX is cross-linked poly, the stuff you say is toxic?
In any case, I'd much rather deal with the "toxicity" of black poly than with the environmental or health impacts of PVC, PVC glue, or salt. This is coming from someone who has done environmental risk assessments as a professional.

Any well that's 6ft. deep is likely contaminated with surface contaminants such as e-coli.

The heat you're trying to contain by insulating the pipe is that in the water as it comes our of your water supply. If that's groundwater, its likely about 50 deg. F. There's a lot of heat released as water goes from 50 to 32 deg. F.

Interesting situation, good luck.

 

[semipro]

another option for a cheap insurance would be to use whatever size pipe you are using, wrap it in blanket insulation and then top coat it with the next size up thin wall pipe. i would still use heat trace in the sections exposed. it will be a pita to put together but will help keeping things from freezing..

How does the addition of the outer thin wall pipe help?

 

[benjamin]

Black poly pipe will survive freezing much better than pvc, but not quite as good as pex. It's usually not the first freezing that pops them, it's when they freeze up at both ends and work their way to the middle.

Insulation will definitely help prevent freezing, though I'm not sure if you need it if you have enough water to keep it running ordinarily. If this water if for domestic use, or livestock water then it would be an advantage to keep it warmer rather than freezing. I'd be more inclined to cover it with dirt than try to insulate or double pipe that length of line.

It sounds like this is left running, so there's no way you'd heat it. Heat tape (one wrap of cheap coax rg59 up and back hooked to 120, but don't tell anybody where you heard that one) would be useful only to thaw it after a freeze up. But rather than start a fire why not put a union every 100' and use a snake a 100' length of pex fed with well water up a section at a time? doesn't that sound like fun? or maybe feed the coax inside the pipe?

 

[cliff88]

Black poly pipe will survive freezing much better than pvc, but not quite as good as pex. It's usually not the first freezing that pops them, it's when they freeze up at both ends and work their way to the middle.

Insulation will definitely help prevent freezing, though I'm not sure if you need it if you have enough water to keep it running ordinarily. If this water if for domestic use, or livestock water then it would be an advantage to keep it warmer rather than freezing. I'd be more inclined to cover it with dirt than try to insulate or double pipe that length of line.

It sounds like this is left running, so there's no way you'd heat it. Heat tape (one wrap of cheap coax rg59 up and back hooked to 120, but don't tell anybody where you heard that one) would be useful only to thaw it after a freeze up. But rather than start a fire why not put a union every 100' and use a snake a 100' length of pex fed with well water up a section at a time? doesn't that sound like fun? or maybe feed the coax inside the pipe?

Unions cost $12 at southern drip irrigation. aholes. i will cover it with sawdust. thanks i will implement your ideas not pay you for your help.

 

[maple1]

Not pay who for what help?

 

[Flatbedford]

Why would you want to "unthaw" the pipe after putting so much time and effort into thawing it out?