2 versus 1 main drain

[RXJ]

I have a 2017 Columbus by Palomino 5th wheel. It has two main drains, one is the black water and the gray water tank drains from the master bathroom. The other drain is from the black and gray water tanks from the kitchen and 1/2 bath. Because of this I have to connect a sewage hose to each drain, a Y connector and more sewage hose from there to the campsite sewage system. At a dump station I have to move the hose from one drain to the other to get everything emptied. For the obvious reason of ease I am considering connecting the two systems together into one common drain line. Naturally I would make the modification down stream of all shut off isolation valves to ensure all tanks stay properly isolated. It would only require a couple of couplings, a tee and short section of pipe, less than 2 feet. I can't understand why the manufacturer didn't do this? Am I overlooking something? Any feed back or comments would be appreciated.

[NeilM108]

You’re not missing anything. It would add a slight bit to the cost and the labour, which is why they won’t do it.

[cavie]

be careful to follow the rules of downhill flow. You my find the end result is plumbing too close to the ground.

[RXJ]

Thanks guys.

[CaptnJohn]

I have 4 tanks going to 1 drain from the factory. Should not be difficult

[Kimber45]

X 2 on what cavie said. allot of rear kitchen units have two outlets because of the distance to the black tank. I would also be worried about clearance and bottoming out damage.

[rockfordroo]

Tying them together usually means running a pipe below the axles, which is why they don't do it. That being said, the bottom of my single drain is only 9" above the ground, and it's behind the axles, so the ground is sometimes closer than 9" (like when exiting a gas station).

X3 on Cavie's comments. (The old joke is that you only need to know 3 things to be a plumber: ***** flows downhill, hot water's on the left, payday is Friday! - Sorry, plumbers - I DO respect you.)

Good luck. Remember to post before and after pics!

[Larry-NC]

Originally Posted by rockfordroo

Tying them together usually means running a pipe below the axles, which is why they don't do it. That being said, the bottom of my single drain is only 9" above the ground, and it's behind the axles, so the ground is sometimes closer than 9" (like when exiting a gas station).

X3 on Cavie's comments. (The old joke is that you only need to know 3 things to be a plumber: ***** flows downhill, hot water's on the left, payday is Friday! - Sorry, plumbers - I DO respect you.)

Good luck. Remember to post before and after pics!

Wonder what happened to Bruce (Nomad387). I don't see posts from him any more.

[rockfordroo]

Originally Posted by Larry-NC

Wonder what happened to Bruce (Nomad387). I don't see posts from him any more.

I think you mean Nomad297. He was on about a week ago.

[burks]

I have a TT by Palamino and it had 2 drains. I added a pull valve and 2 90s and a short piece of pipe. Isolated the kitchen tank and the outdoor kitchen tank. Now all three tanks drain through one place.