Up at my old mobile home I'll have the city turn the water off, 3/4" copper installed in the 70s.
From the shutoff it's about 30' before it comes up out of the ground.

Not sure when or if it'll be used again so I worry it could fill with water and freeze splitting the copper.

Couple ideas I've had:

• run plastic hose down 8' from compressor then blow it out, add RV antifreeze and close valve on top.

• just blow most of the water out and hope the shutoff doesn't leak and eventually fill the pipe.


I don't know if the RV antifreeze will hurt the copper after a while, I'd guess the city's valve is good but who knows?

Thoughts?

Thanks

 

RV antifreeze will not cause issues.

If you blow it out, then no need for antifreeze!

 

Agreed, you definitely want to blow out all the lines in the home.
You'll want some RV Antifreeze in the toilet and sink traps.

The underground line should be fine as it should be buried below the frost line.

 

I used standard antifreeze in the toilets in my vacation home for 30 years and sucked it out with a baster each spring to reuse. Last year I used RV antifreeze and found in the spring that it had evaporated. Rather than go back to standard AF this year I will stuff the toilet outlets with rags after removing all the water. I will still use RV AF in the sink traps since closing the drain stoppers may reduce evaporation but will also block any sewer gas from coming out.

 

Interesting about the evaporation. I have a jug of used antifreeze from my truck, I might just dump that in the toilet and the RV in the sinks and tub.

Water heater is in the back bedroom, all copper lines to the front. Picked up a reducer thingie where I can connect my compressor to the 3/4" flexible copper lines on top of heater and blow everything out toward the front... should work.




If I set the regulator on compressor to 30# will it stay at that pressure even when I shut off a faucet to move to the next one? Hate to blow something up.

Thanks, warmer weather next week.

 

I stopped using regular anti-freeze since I was concerned about contaminating my septic field near a lake. For many years I used it in the sink and tub traps as well as in the toilet. If you have an accessible outlet on your trailer you could use regular AF in all the traps and capture it at the outlet but then you would have the problem of disposal of a significant amount of diluted AF.

RV anti-freeze is non-toxic so it can be used in the supply lines but blowing them out is fine too. Using RVAF in the traps avoids the problem of disposal.

If you set the outgoing pressure of the compressor to 30# that will keep the pressure feeding your pipes at 30# or less. The tank pressure may be higher and the compressor will shut off at its set point.

I have a small 3 gallon pancake compressor that I connect to a (washing machine) hose connection . It is set for 60#. First I drain all the pipes and HW tank by gravity. Then I close all the valves (including the valve at the toilet), isolate the hot water tank so I won't be trying to pressurize its large volume, and let the compressor run for a while until the pressure builds up. Usually the pressure won't get to 60# and the compressor keeps running. Then I go to each faucet, toilet, hose bib, etc. and open it to expel any water that did not drain by gravity.

For many years I just drained the system by gravity. I installed it myself with that in mind but due to later installations of a retractable kitchen faucet and a mixing valve, both with check valves, and a couple of toilet valve freeze-ups I now do a blow out as well.