JJBIRISH wrote:
A dry system wouldnโt need protectedโฆ but I havenโt seen a dry system that was used until winterization and then blown outโฆ yes they had compressed air run through them to empty the bulk waterโฆ but they are not dry, and I have repaired more because they thought the system was dry, and it wasnโt, than for any other reasonโฆ I have never repaired one the was winterized with the pink stuff when done properlyโฆ
As a matter of fact every one that I was told was winterized with air alone already, I was able to blow more water out of the lines a week or a month laterโฆ sometimes a significant amount of water ( I know, I hear it all the time, I have done it for years with no problems)โฆ
Sometimes the plumbing is stubbed out for an outside shower or a washer that was never installed, if you look at most RV plumbing installations itโs easy to find one low spot after anotherโฆ blowing the lines out seldom gets all the water out and works as long as enough of whatโs left behind doesnโt pool in one spot or fittingโฆ
You are spot when you say "when done properly" but the use of air or pink stuff matters not IMHO.
I rarely see anyone doing it properly with air, you need a large reserve, 10 gallons minimum, 20+ is better. Once the initial blast of water is cleared there's still a LOT of water left in the lines and it takes a sustained flow of pressurized air to drive those drops out. A little 2 gallon unit doesn't make, or hold, enough air to do that.
A buddy of mine keeps his unit at my place, after he finished blowing the lines on his RV I ran the line from my shop compressor (5hp with 120 gallons of tanks) and hooked it onto his adapter. He was amazed at how much more water came out!
If the compressor you're using to blow the lines isn't capable of maintaining 50 - 60 psi with a wide open hose, it isn't up to the job.
