RVs are supposed to be factory tested to at least 100 psi. RVwaterfilterstore.com recommends operating at 60 psi (for adjustable regulators) and that's what I have ours set at. Some CGs have pressure well over 100 psi and 100 percent of campers won't have a regulator and you don't hear about RVs blowing anything inside from high pressure. I've seen CG pressure as high as 140 psi and it reportedly can get as high as 200. 100 psi is nothing for PEX piping. It has a memory and even if severely kinked or stretched will return to it's original shape & size.
If you have a small portable electric compressor it's unlikely you'll have to worry about too much pressure as you won't getting much cfm to keep pressure up with an open faucet/valve. Regardless of your compressor size, adjust the regulator down to a level you're comfortable with. I used to use a Porter Cable pancake compressor and now use my shop compressor and turn down the regulator a bit (usually set at 90 psi for air tools). I used the pancake compressor for winterizing several winters and never had a problem but some are concerned these will leave some moisture in the lines. Even if some water remained in the PEX lines they can withstand repeated freezing.
There's two types of winterizing adapter fittings for a city water or black flush inlet. One uses a standard quick connect fitting and the other uses a schrader valve. If worried about pressure, use the schrader valve adapter and fully open a faucet/valve first then go hold your air chuck against the schrader valve until all the water is expelled. Or use the quick connect version and turn your regulator down to 45, 60 or what you are happy with. I use the latter as it's easier for one person and you don't have to keep running outside when it's rainy and/or cold.
Use a water trap and filter to keep remove moisture and undesirable stuff from getting inside your RV.
If you have a small portable electric compressor it's unlikely you'll have to worry about too much pressure as you won't getting much cfm to keep pressure up with an open faucet/valve. Regardless of your compressor size, adjust the regulator down to a level you're comfortable with. I used to use a Porter Cable pancake compressor and now use my shop compressor and turn down the regulator a bit (usually set at 90 psi for air tools). I used the pancake compressor for winterizing several winters and never had a problem but some are concerned these will leave some moisture in the lines. Even if some water remained in the PEX lines they can withstand repeated freezing.
There's two types of winterizing adapter fittings for a city water or black flush inlet. One uses a standard quick connect fitting and the other uses a schrader valve. If worried about pressure, use the schrader valve adapter and fully open a faucet/valve first then go hold your air chuck against the schrader valve until all the water is expelled. Or use the quick connect version and turn your regulator down to 45, 60 or what you are happy with. I use the latter as it's easier for one person and you don't have to keep running outside when it's rainy and/or cold.
Use a water trap and filter to keep remove moisture and undesirable stuff from getting inside your RV.
