air compressors for blowing out water lines

FrankandCarolyn

I need to be able to blow out my lines on my 2018 400 for winter travel.  Any suggestions on the right size & type of small portable compressor?

Dutch061

Places like Harbor Freight have several to choose from. If you are only going to use it for blowing out lines, it can be a very low priced compressor. Make sure to regulate the PSI to 50 or less to prevent damage to the plumbing.

I have a small pancake compressor that I use for tire inflation and a small air nailer. I turn the regulator to 50 PSI and make my connection to the camper. 

Brad

Sharon_is_SAM

Recently discussed:  https://tab-rv.vanillacommunity.com/discussion/13792/recommendations-for-an-air-compressor-to-purchase
https://tab-rv.vanillacommunity.com/discussion/comment/151651#Comment_151651

Easy to use the search function.  I searched “compressor”.

BrianZ

Look for something with the highest CFM rating (cubic feet per min of sustained air flow at a given pressure), because that's what will push water out of the lines most efficiently.  Pressure is mostly not an issue, since you want to keep it below about 30psi to be safe.  Compressors with tanks and two gauges generally yield the most CFM (one gauge for high pressure in the tank, and another to regulate the pressure to below 30psi output in the hose.

Dutch061

You could also install one of these https://store.lci1.com/floe I have thought about it but haven't moved forward on it as of yet. 

Brad

P.S. even the most inexpensive compressors will develop enough CFM at the less than 50 PSI to be able to remove the water. The device listed above has minimal CFM

BrianZ

In my opinion..
Most any air compressor, even a bicycle pump, can remove some water; however, those with an insufficient sustained flow rate will tend to leave more water behind, especially once the column of water in full pipes is broken.  If that water is left in a critical space (such as that pesky toilet valve for example), even a small amount can do damage when frozen. 
On the other hand, from the "glass half full" perspective, removing most of the water will give some degree of added protection and is certainly much better than nothing.  It may also depend on how much time and effort you are willing to go to, since a lower flow rate may require more time or repeated attempts at blowout to remove a sufficient amount of water.  The "Floe" video appears to demonstrate some of this, where they have to wait for its 15 psi pressure to built back up before moving on to the next faucet. 
I bet one could build their own "Floe" system at much lower cost, if they could just make the "T" fitting with one-way check valves, like some of the T@B plumbing has.  Not sure I see the need to have a built-in system, though it could be handy for some.

SLJ

Made this for my motorhome. Will use it on the T@B now. Just remember to always keep a faucet open before starting the air when blowing out the lines. When done with one, open another before closing the first one. 

pak

I run a lot of air through the lines after the initial rush to help dry any residual water. As mentioned the toilet valve is often easily over looked. Another overlooked place is the water pump.

BrianZ

@pak, speaking of the toilet valve & water pump, after blowing out our system, I connect our pump directly to the toilet line & pump antifreeze through both.  This also serves to protect the valve in the bowl as well as the gray tank dump valve.

pak

BrianZ, that certainly a thorough system. Protecting the blade valves on the gray and black water discharge lines is a good idea.