Plumbing for portable grey tank only

[Xtremespeed]

Same to you and thanks for the ideas. I'm up and running. Just need to try the 3/4" garden hose just to see if it will flow enough. I have the connections for 3" now too so if it doesn't work, I'm still good to go.

[RamQuad4x4]

I ended up using 2" for the shower p trap reduced to 1 1/2" and 1 1/2" for the sink. I connected both sides with a y and and then reduced a standard 3" outlet to 1 1/2" to fit the y. I bought one of the caps you suggested with the garden hose fitting. It will serve as my cap when traveling and when the ct is not in use and if the garden hose connection works, great, and if not, I can remove the cap and use a standard sewer hose. It all turned out pretty good. I just wish there was a way for the shower p trap not to hang quite so low, but I installed my shower directly to the floor, so the entire p trap is below the floor. It's not real low, but I wish it was above the bottom of the frame. I did manage to keep the 3" outlet tucked up in there. You you have to reach up under there to get to it, but I don't have to worry about knocking it off, and whenever I need to access it, there will be no water flowing out since I don't have an onboard tank.

I'm new to this forum and planning a build of my own in the near future. It's been quite some time since this thread has had any updates so this may be useless to the original poster. I am planning on putting in a shower and sink as well but will most likely not use p-traps to minimize the depth of piping below the trailer as mentioned above. In order to keep the smell from coming back through the drains from the grey tank I plan on using trap-guards http://www.trapguard.com/. I design plumbing systems for a living and have used these on may applications. Granted they are typically used with p-traps to avoid needing trap primers but I'm only looking to block the smells from coming back in. This will minimize the depth of piping below the trailer as well as serve a similar purpose as a p-trap.

[Mark519]

The HepVo waterless valve is another option http://www.hepvo.com/

[RamQuad4x4]

Thanks Mark519. Looks like they use the same concept but the Hepvo is already installed in piping and is cheaper.

[bdosborn]

Fits on a standard bar sink drain and has a garden hose connection on the downstream end:

Camco 37420 RV Flexible Camper Drain



Bruce

[roadinspector]

Thanks for the info!! I see a hepvo going in my CT.

[norcal2]

Fits on a standard bar sink drain and has a garden hose connection on the downstream end:

Camco 37420 RV Flexible Camper Drain



Bruce

I used this on my sink..the hose is way to short i just went to home depot and bought a longer piece works great!

[bdosborn]

Thanks for the info!! I see a hepvo going in my CT.

Do you really need a backflow preventing valve? You're not hooking up to a sewer and there shouldn't be any gas coming back from your portable grey water tank. I've never had an issue with smell coming back up my drain and I connect to a portable grey water tank.

Bruce

[pete42]

Thanks for the info!! I see a hepvo going in my CT.

Do you really need a backflow preventing valve? You're not hooking up to a sewer and there shouldn't be any gas coming back from your portable grey water tank. I've never had an issue with smell coming back up my drain and I connect to a portable grey water tank.

Bruce

I'm glad you ask I was wondering the same thing........waiting for an answer.
pete

[roadinspector]

Old school thinking when I'm used to p-traps on any drain line. Like you said it's only grey water. Even with some food waste in it from washing dishes, the tank will be drained before it gets any form of ripe. Thanks guys!