plumbing doesn't match manual

[adwriter73]

I'm planning on replacing much of the copper plumbing above the floor with PEX and currently trying to understand the plumbing system. I have a service manual with a plumbing diagram. The problem is the manual doesn't quite match my system at the water pump. I'm guessing this is because a past owner has messed with the pipes. So...my question is what do I need to make sure the new PEX lines have, i.e check valves, pressure regulators, etc.? The manual doesn't clearly state any of this.

[TG Twinkie]

The pump may have a check valve built in, but just for safety sake I installed a manual valve that I close when on city water. You can install a pressure regulator inside of the trailer, but I chose to use one that attaches to the end of the hose and connects to the water inlet. The way I look at it the fewer things you have permanently installed in the trailer plumbing the better off you are. I have posted a photo of my installation on previous threads with everything identified. I have reached my limit for posting photo's or else I would post it here again. All of my valving is in one convenient location, inside the cabinet in the bath. It's a pretty simple system, cold water goes from the pump to the water heater, the toilet, the bath sink and shower/tub and the galley sink. The hot water starts at the water heater and goes to the bath sink the shower/tub and the galley sink. I eliminated the drain valves as they are rarely in the lowest part of the plumbing system. Use compressed air to evacuate the water then fill the system with RV anti freeze, only the pipes get anti freeze. I drain the holding tanks and water heater.

[Tom Nugler]

Originally Posted by TG Twinkie

I eliminated the drain valves as they are rarely in the lowest part of the plumbing system. Use compressed air to evacuate the water.......

TG's got it right. The extra valves spread all over the coach are IMHO totally unnecessary if you're using compressed air to evacuate the system.
I don't add antifreeze to the drained fresh water tank. Fore and aft plus low side draining has worked well in the past. I feel there is plenty of room for expansion in that large of a tank. I find it takes forever to get the antifreeze taste out of the water. I do add it to the sink and shower traps. All of mine were damaged by the PO not taking this simple precaution.
Dump the drain valves. Simplify wherever possible.

Good luck,
Tom

[adwriter73]

Thanks guys. Very helpful. TG, I will look up your past postings to find your photos.