Blowing pipes

[DeltaRon]

Just to clarify, what's the max psi to use thru the blow-out plug? AS recommends at least 60 psi. Also, do you leave the low-points drains open and what about faucets; should they ALL be open or one at a time. We just need the process steps. Thx


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[dznf0g]

I use 60psi. Fill the closed system with pressure and open faucets one at a time, starting with the furthest away from the city water inlet. Repeat twice and then open the low point drains, one at a time. Don't forget the outside shower or spigot (in my case...no shower outside but there is a spigot in the lower water compartment.)

[Wayne&Sam]

And don't forget the kitchen sprayer and toilet.

[Wingeezer]

I generally blow the system out and also use plumbing antifreeze!

I guess is is maybe redundant, but I have heard that when blowing the water out, it is still possible for residual amounts to pool someplace with the pipes and cause freezing problems.

I think many people only blow out the system without problems, but if there is any chance of a freezing problem, I'd just as soon do all I can to avoid it.

I have usually used about 40 psi.

The first year we had the trailer, I didn't realize there was a toilet sprayer - the previous owner had it tucked away in the back of the toilet out of sight!

Result - new sprayer and hose kit for about $45 ! Live & learn!


Brian.

[IanPoulin]

I use 60 psi, with low points closed to keep a closed system. start with one (I choose kitchen cold) faucet open, let the pressure in, then move in a fashion through the trailer; ala --

kitchen cold on, wait till clear
shower cold on, kitchen cold off, wait till clear
kitchen hot on, shower cold off, wait till clear

etc, etc.,

also, dont forget to hit the black water inlet line.

Ian

[ROBERTSUNRUS]

Hi, I use about 40 lbs pressure like Brian. [more pressure could rupture a weak spot] It's not the pressure, but the volume of air that pushes the water out of the lines. This year after a good blow out, I only put the pink stuff in the traps.

[IanPoulin]

There's a fellow in Charlottesville (colder than here) who also does that -- blows the lines out, puts the Anti-freeze only in the traps; never has had issues.

the final thing I do, only as my father passed it on, is leave the gate valves open on the black/grey tank release

[dznf0g]

I blow the lines and fill with AF as well. I had residual drop left in shower valve on an sob. It froze and cracked ....but I lived in Michigan then.

[Siegmann]

My 98' has a Shurflo accumulator plumbed in under the sink. It was mounted with the pressure inlet at the bottom (for easy access?) and the water in/out fittings on the top. According to Shurflo, this is not the best way to mount it:

"Can be mounted in any position. However, for complete sanitizing/winterizing, the recommended mounting position is with pre-charge valve stem up."

I presume, that if you only blow out your lines, a freeze could crack residual water below the top of the accumulator, if it is mounted with the plumbing at the top. If you have an accumulator, I advise you to check how it is mounted.

[Alumineer]

Originally Posted by Siegmann

I presume, that if you only blow out your lines, a freeze could crack residual water below the top of the accumulator, if it is mounted with the plumbing at the top. If you have an accumulator, I advise you to check how it is mounted.

The other reason is that if the pressure port is at the top, then even if the diaphragm fails, you will have air at the top and water at the bottom and the system will work as intended. If the air fitting is at the bottom and the water fittings at the top, a diaphragm rupture will let the tank fill with water and you just get a big burp of air from the tank instead of steady water pressure.

Our hydronic (pipes in concrete) basement/garage heating system has an accumulator where this happened (the rupture, not freezing). Remedy is a new tank and mounting it proper side up.

[ROBERT CROSS]

POI.....my 25gal dual stage shop compressor, set at 120psi supplies a steady 35psi with the delivery valve wide open on the gauge....the amount is just as important as the pressure.



I NEVER apply air on a closed system....at least one outlet open at all times.

Bob

[sarasafari]

Where is the blow out point? The city water outlet?

[Ted S.]

I just blew mine out yesterday. Charged the closed system to 20-25 PSI ( less than water pressure) then opened one faucet until the pressure was gone. Repeated for each faucet.

Even on the 4th or 5th blow you could hear water gurgling albeit less and less faint.

When I received my Airstream from the factory in November, it was winterized with antifreeze. I figure that's telling me something.

[Siegmann]

Returning to the Shurflo accumulator one more time, the the manufacturer indicates that more than 40 psi on the pressure side of the diaphragm/bladder could result in damage if not offset by water pressure. Seems like if you pump in 60 psi air pressure on the water side (while the system is closed) you could be risking damage.

[Ted S.]

Originally Posted by ROBERT CROSS

POI.....my 25gal dual stage shop compressor, set at 120psi supplies a steady 35psi with the delivery valve wide open on the gauge....the amount is just as important as the pressure.



I NEVER apply air on a closed system....at least one outlet open at all times.

Bob

I agree on the volume concept, however I used my traveling air compressor to simulate how things would be winterizing on the road. I figured as long as my PSI was lower than what the system experiences when pressurized with water, I should be ok.