Water lines

[Blay]

When blowing out water lines with a compressor what’s the secret to keeping constant regulated pressure thank you

[lane_hog]

Oh, I'm sure the lines will handle higher pressure, but it's simply not necessary just to drain the lines.

With properly functioning low point drains, simply opening the faucets and shower head does most the work for you. Running air will disrupt whatever air pockets might have formed and stopped gravity from doing its job.

[ajriding]

Why?

The RV pipes can take 150 psi of water easily. Water does not compress, air does!

45 psi of air at the nozzle will not be 45 psi of air pressure once in the water pipe system, it will drop way lower because the pipes are way bigger than the air hose. If the water heater tank is empty then psi will drop way way down (maybe 5psi) and as long as there is no blockage on the downstream side of the pipe then air pressure will not build up much at all.

I would imagine you could blow in 300psi and nothing would happen, the drop in psi from 300 at the air nozzle to what it would be in the bigger longer water pipes would be enough of a drop to not be an issue.

Again, air will compress, unlike water that has nowhere to go, air will compress in itself so need nowhere to go.

Very likely your air compressor cannot give enough psi to do any damage to anything in your RV.

I do not recommend using a 100 gallon commercial 300 psi air compressor to blow out your air lines, but if you do then just do short burst of air, not a long steady flow of high psi air just to be safe, because i have not done testing with air in pipes, but I do know those same water pipes are used for these 300psi air compressors.

I guess the bigger concern is your faucets or the stop-valve on your water pump.

[lane_hog]

I try to keep it below 30 PSI which is lower than most city water connections. You don't need that much pressure to blow them out, and a few remaining droplets won't hurt the fittings.

[CavemanCharlie]

Sjm9911 wrote:
Bypass the water heater, or you will need a lot of air.

Not if you drain it first. That is what I do and then use air to blow out the rest.

[deltabravo]

Yep. Set a pressure and call it good.

I use about 25 PSI.

Video showing how I do it

[GrandpaKip]

I just set the compressor to 45 psi.

[Sjm9911]

Bypass the water heater, or you will need a lot of air.

[CavemanCharlie]

I have a portable air tank. I just put 40 PSI in it to blow out my lines. If I run out of air in the portable tank then I just fill it back up. I have a small TT but, it never takes more then 2 tanks.

[gbopp]

Are you using an RV Blow Out Plug to connect the air line to your water line?

[jdc1]

A BIG tank.......with a regulator on it.

[schlep1967]

2oldman wrote:
A tank.

With a regulator on it.

[2oldman]

A tank.