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Mitchell-DIY-Guy

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Coming from a land where you design things to PREVENT pipes from freezing, and frozen pipes "are a thing" and cause of many issues, imagine my surprise when I discovered a crew INTENTIONALLY freezing a pipe at my home yesterday.

The contractors for the City of Charlotte came by to add a box for a new irrigation meter. This "Tees" off the house water line, before the existing meter. Well, the water system design here doesn't have any shutoffs at the main or anywhere before the meter; the only shutoff is integral to the meter. So, how do they "shut the water off" so they can add a Tee? They freeze it.

https://pipefreezekit.com/PDFs/arctic-freeze-specs2.pdf
Once frozen they had about 5 minutes to cut and splice in the Tee. You learn something new every day!
 
Freezing pipes to stop water flow has been discussed in here occasionally. I too am amazed at how well it works.
 
There is a recent episode on This Old House where they demonstrate the 'why' behind typical household freezing pipe. Its not the water. Its the air pressure. Which is why 'dripping' works because it release the air pressure build up.

Things they never taught you in Physics class.
 
Doesn't make sense. Air has the ability to expand, water doesn't. You sure they were not talking about water pressure as opposed to air pressure?
How you gonna get AIR pressure inside your water pipe? Yes, fluids don't compress or expand, until they change to a solid. In this case water to ice. Running a drip merely keeps the water from freezing.
 
Domestic water, whether from a pump (well) or city sourced, is fairly consistent in temperature, adjusting for season and geography. Say, 50 degrees. But, water has to be 32 and below in order to freeze. If you are dripping water out of a faucet in a freezing environment, you are displacing water at or about to freeze, with "warm" water at 50 degrees. THAT'S why a dripping faucet won't freeze.

I have not heard of anything to do with air pressure; I suspect that Birkoff misunderstood This Old House's demonstration. What they said was that when a length of pipe freezes--i.e. a slug of water in a pipe (remember there's rarely air in a pressurized water system) gets frozen, that water expands by 9%. That ice (not air) exerts pressure on the rest of the water in the system. Water won't compress; so now this highly pressurized water is finding the weak spot in the system and will cause a pipe to split, a joint to open or a valve to crack.

You can prevent this by providing a path for the water to go. Turning off water at the main, or turning your well pump off and depressurizing your system and leaving faucets open will prevent most bursts from freezing, as the ice in the pipe will push the water out the open faucets rather than crack a pipe or valve.
 
And not all liquids e x p a n d when they freeze, in fact, water is one of the very few that expand, most contract.
 
The answers above hit on many of the “truths” about water. Here are some tabulated facts:
Water is at its densest at 4 degrees C. It expands at temperatures both above and below 4 degrees.
Anything added to water, be it sodium from softeners, chlorine, calcium or air will raise the boiling point and lower the freezing point. But the temperature of maximum density is unchanged.
While it is true that liquid water is considered as a non compressible fluid, that is not exactly true. It is “practically” non compressible. Consider: You have a tank that is full to the brim with water. No air, no empty spaces inside. You have a gauge connected to the tank. You want to raise the pressure in the tank to 1000 psi.How? The tank is already full! Well, the deal is you have to add more water. Not very much at all, but yes, water is slightly compressible.
You can freeze water in a pipe as described above with no damage easily. You must: Make sure that the freeze plug is far enough from a dead end of the line so that the “slightly compressible” property can absorb the pressure produced by the freezing water. It is this effect that in northern climates cause frozen pipes to burst near the ends of fixture branches. (Air chambers do not protect these branches because they “waterlogged” by dissolving the air trapped in them)
Two ice plugs near each other will almost always burst the pipe.
 
I own a Rigid pipe freezing machine , have not used it as much as I would have thought . Heavy and need a straight length of pipe to connect it to . Thought about the gas system but hate to refill bottles . It has worked well but it has split a pipe once in about 20 times I have used it . . Good to have a back up plan if you want to use it .
 
Coming from a land where you design things to PREVENT pipes from freezing, and frozen pipes "are a thing" and cause of many issues, imagine my surprise when I discovered a crew INTENTIONALLY freezing a pipe at my home yesterday.

The contractors for the City of Charlotte came by to add a box for a new irrigation meter. This "Tees" off the house water line, before the existing meter. Well, the water system design here doesn't have any shutoffs at the main or anywhere before the meter; the only shutoff is integral to the meter. So, how do they "shut the water off" so they can add a Tee? They freeze it.

https://pipefreezekit.com/PDFs/arctic-freeze-specs2.pdf
Once frozen they had about 5 minutes to cut and splice in the Tee. You learn something new every day!

They do it live and get wet here. It’s fun to watch. 🤓
 
How do you explain a water heaters thermal expansion if fluids do not expand until they change to a solid ? If you heat cold water it expands.

"Fluids don't compress or expand" is when the fluid is at a stable temperature. That's the basis of all hydraulically actuated systems. If the hydraulic fluid compressed, it couldn't transfer the power from the actuator/pump to the motor or tool.
 
"Fluids don't compress or expand" is when the fluid is at a stable temperature. That's the basis of all hydraulically actuated systems. If the hydraulic fluid compressed, it couldn't transfer the power from the actuator/pump to the motor or tool.

That’s not what he said 🤣
 
The answers above hit on many of the “truths” about water. Here are some tabulated facts:
Water is at its densest at 4 degrees C. It expands at temperatures both above and below 4 degrees.
Anything added to water, be it sodium from softeners, chlorine, calcium or air will raise the boiling point and lower the freezing point. But the temperature of maximum density is unchanged.
While it is true that liquid water is considered as a non compressible fluid, that is not exactly true. It is “practically” non compressible. Consider: You have a tank that is full to the brim with water. No air, no empty spaces inside. You have a gauge connected to the tank. You want to raise the pressure in the tank to 1000 psi.How? The tank is already full! Well, the deal is you have to add more water. Not very much at all, but yes, water is slightly compressible.
You can freeze water in a pipe as described above with no damage easily. You must: Make sure that the freeze plug is far enough from a dead end of the line so that the “slightly compressible” property can absorb the pressure produced by the freezing water. It is this effect that in northern climates cause frozen pipes to burst near the ends of fixture branches. (Air chambers do not protect these branches because they “waterlogged” by dissolving the air trapped in them)
Two ice plugs near each other will almost always burst the pipe.
You took physics' in high school, so did i, it shows .
 
I never heard of such - freezing a water plug to get in and make some changes (without needing a complete drain in every situation.) Though draining some may be needed in places you'd have to solder, so I think if you're going to solder you might drain less of the system by plugging a run with ice, where that might work - looks like there's some iff's. But it doesn't look like a 'cure-all' for every situation.

My current two-story residence seems to have been built without a central, cold-water shutoff. The only shutoffs I've found are under sinks, commodes and at the waterheater. Hmmm, is that really proper? House was built in a suburb by a developer alongside 100's more similar houses in the mid-70's. (copper throughout, but fittings like shower valves are starting to wear out, past the point of repair.)
 
My current two-story residence seems to have been built without a central, cold-water shutoff.

Here in the climate of NC, not much different than Georgia, there are two shutoffs: one at the meter in a box at the street, and the other well inside the house. The cold water line comes in the front of the house, into the crawl space, runs along the floor truss system until it gets under the laundry room. There it comes up and in the wall (behind a removable panel) there's a main shutoff prior to the pressure reducer, then a tee with two additional shutoffs. One goes to the hose bib's (white PEX) and the other to the home's cold water system (Blue PEX).

In many of the homes I inspect, built on a monolithic slab, the water line is under the slab, comes up into a wall in the garage by the hot water heater. There you have the same shutoffs and pressure reducer.
 
Thank you. This house has a valve at the street which is technically the water company's. It should have a valve under the house to isolate the house system from inlet pressure, in the mostly finished basement. I've looked twice, but have yet to find it. I'm going to have to go through the 'office', a finished room between the meter and the utility area holding the waterheater, and remove all of the drop-ceiling that may conceal it and the water line, and trace it as carefully as it takes.

After the office I beleve the water line must go through the 'shop.' This is an unfinished area with studs on-slab. For years and years people have rigged plumbing changes or repair, electrical, HVAC, and whatnot under the joists (its ceiling) into such a tangle that it's pretty hard to see what's what. I'll probably use different color masking tape tags to try to ID and separate it all out. Luckily there's no really complex systems, it's just a real mess.
 

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