How to replace/re-engineer leaking fresh water drains

Well, I'm about halfway there. With the help of a Dremel to cut off the PEX crimp on the tank drain, I finally got both the tank and system drains removed.

I was able to repair the old tank drain by tightening the packing nut. This is a picture of the ready to reinstall tank drain assembly with teflon tape on the tank fitting threads.



I bought what I thought was the most appropriate system drain (Flair-it 180 Degree Center Drain Valve 06914) from RVplus.com.



Based on responses to this topic posting, I was going to use PEX tubing into the valve's Flare-it connectors, but I am concerned about RV and water pump vibrations causing leaks. Also the acute connection angles are probably not achievable with rigid PEX tubing. Here is a photo of the old push-pull drain valve after it was removed: (note the hose-type connector for the water pump)



Is there a flexible type of tubing that will work with the Flare-it connectors? The only 1/2" i.d. flexible tubing I could find at the local hardware stores has an outside diameter too large for the compression collar.

Alternatively, should I add threaded connector adapters onto the water pump and system sides of the drain valve so that the drain is connected with flexible supply hose?

Since I do not have a PEX crimp connector tool, I am trying to use Flare-it connectors on the PEX, but is it possible to use screw-tightened hose clamps with PEX?

This seems to be getting overly complicated. It would be much simpler if I could find a flexible hose to fit in the Flare-it connectors.

Thanks for the help.

My low point drains have no valve, just a cap on the end.

http://rvparts.unitedrv.com/Plug-Cap-Each-889241

I plan to just open the defective valves and add a Flair-it valve outside the trailer on the drain tubes. Will that work for you?

wgriswold wrote:
I plan to just open the defective valves and add a Flair-it valve outside the trailer on the drain tubes. Will that work for you?

Good idea, but a little late for me since I cut out the PEX connector and butchered the supply line in the process.

Also, the blue drain is not PEX. It's some kind of larger poly.

ImaginaryNumber wrote:

wgriswold wrote:
I plan to just open the defective valves and add a Flair-it valve outside the trailer on the drain tubes. Will that work for you?

Good idea, but a little late for me since I cut out the PEX connector and butchered the supply line in the process.

Also, the blue drain is not PEX. It's some kind of larger poly.

Bummer!

I'd suggest to use some reinforced hose like you had in parts of the system in lieu of the poly pipe.

If it was me, the whole mess would be scuttled and full-flow ball valves would be the shut off of choice. I'd probably plumb it all with pex, the proper fittings, and crimps, and choose a sharkbite fitting into the tank to ease installation. Any plumbing that needs support would be tied into a stable part of the frame or ancillary support with appropriate pipe hangers.

Finally got it finished.

The water tank compartment is now even more tightly packed because of the larger system drain and all the connection adapters I needed to install. Here is a picture of the compartment (before reinstalling the heater duct):



Here is a close-up of the system drain. I tied into the PEX remnant from the original supply line, but had to use 1/2" id flexible tubing between the pump and drain valve:



Here is a close-up of the tank drain. I simply cleaned out and tested the old valve and re-taped the MPT connections into the tank:



Thanks for everyone's help.