130 psi compressor for winterizing?

[Beau_Bo]

Hi - looking at at a Viair 400p compressor to carry al0ng for airing up tires, etc. It is capable of putting out 130 psi and 2.3cfm which is desirable for filling up the truck tires. Another use I am looking at for it is to blow down my camper water lines for winterization. I would approach this cautiously with several faucets open before turning on the air, just wondering if even with faucets open this might be too great a volume/psi input and it might over pressurize my water system. Thoughts?

[wa8yxm]

Do what I do.. use a pressure regulator between Compressor and RV. I set mine to 50-55 PSI for blow outs. Remove it from the line for inflation of tires.

[OldRadios]

I made a compressor fitting with an on/off valve. I have a 6 gallon 150 PSI compressor on board and have no problems with adjusting the flow with the shut off valve in the line. I always leave one faucet open and open another before shutting the first.

[Boon_Docker]

westend wrote:
If you have PEX pipe in the RV and you don't have a cheap filter canister, you should be OK with the little Vlair.

FWIW I have the older air pump system and the fresh water tank is pressurized to push water rather than a pump drawing from the tank. There is a Schrader valve on the fill cap on the exterior. There is also a pressure gauge in this cap. I start my construction grade Hitachi and pressure the tank and system. My pex supply lines are all new, BTW.

I start at the furthest fixture, the bathroom sink, and open that valve. I only have the toilet, shower, and the Kitchen sink after this. Last time, I shuffled back outside to the fill cap and it read 90 psi. That was unexpected but it was a good test for my new plumbing.

You need volume to blow out water lines properly, you have the volume with your system. There is no volume with the compressor the OP is asking about.

[westend]

If you have PEX pipe in the RV and you don't have a cheap filter canister, you should be OK with the little Vlair.

FWIW I have the older air pump system and the fresh water tank is pressurized to push water rather than a pump drawing from the tank. There is a Schrader valve on the fill cap on the exterior. There is also a pressure gauge in this cap. I start my construction grade Hitachi and pressure the tank and system. My pex supply lines are all new, BTW.

I start at the furthest fixture, the bathroom sink, and open that valve. I only have the toilet, shower, and the Kitchen sink after this. Last time, I shuffled back outside to the fill cap and it read 90 psi. That was unexpected but it was a good test for my new plumbing.

[bid_time]

2oldman wrote:
I think I'd prefer a tanked compressor for that job. It's about blowing a lot of air through the lines, not pressurizing them.

I think this is the answer you should pay attention to.

[Boon_Docker]

I think you would be pretty disappointed with the lack of volume for blowing out water lines.

[tvman44]

Get a little regulator to put in the line b4 the camper and set it for abt. 40 psi.

[Tin_Pusher]

I thought I'd try blowing down rather than antifreeze this year. What I learned:

A 3 gal HF pancake compressor ain't really up to the job. Needed to get done BEFORE spring 🙂

Bigger the tank the better.

[ksg5000]

I have been using an inexpensive 12 volt compressor to winterize my rig for 20+ years - same compressor that I use to inflate my 65 PSI tires (ain't fast but it works fine). Anecdotal evidence that you don't need "bigger" to blow water out of RV water lines.

[2oldman]

I think I'd prefer a tanked compressor for that job. It's about blowing a lot of air through the lines, not pressurizing them.

[RoyB]

If that VIAIR model is a tankless type it will takes longer to build up pressure each time you turn it...

My 12VDC Air Compressor is a tankless type and I have plenty of time to turn it on and walk inside my POPUP trailer and open a water spigot...

I have the older MV50 Tankless 12VDC Air Compressor.

Roy Ken

[DrewE]

The simplest and best solution in my opinion is to get an air pressure regulator for use when winterizing. Harbor Freight (among other many places) sells small ones that would be perfectly sufficient for this use for a few dollars. You don't need anything too precise or consistent for this use.

Always leaving a tap or valve open should prevent any great pressure buildup in the plumbing lines. They theoretically ought to be able to withstand 130 psi, though any slugs of water that are being blown along could produce much higher stresses due to their inertia when they hit constrictions etc.

[Trackrig]

It should work if you do it very cautiously. The Viair, while it will put out high pressure, is still a low volume air compressor.

Open all of your faucets before turning on the Viair. Then start the compressor, let it run for a moment until water and air are blowing out the faucets. Let it run fur a while.

After about 5 minutes, shut one or two of the faucets. Watch how hard the air is blowing out of the rest of the faucets. You want to judge that the air coming out of the faucets is no more than 45PSI that can hurt the plumbing.

As I think about this more, the Viair being a high pressure but low volume compressor, it might not put out enough air volume to blow out water lines?

Whatever you do, don't shut all of the valves. If all the valves are closed it will develop enough air pressure to rupture things.

Bill

[dons2346]

I would not want that much pressure in my water lines, especially the water pump. If yo could dial it down to 45 psi, that would be fine.