Cedar Creek gray water tanks

This is my second trailer with a twist on valve. Should be standard equipment. Not only can you equalize the tanks with it but you can eliminate the poop shower when you take off the camp to dump that's always waiting there from residual drainage into the plumbing. I don't use anything additional to hold mine on. No glue no extra support, nothing. Hasn't moved in thousands of miles.

B.O.

Had the same issue I bought that same valve and open both grey tanks so the fill together.

RV Waste tanks have roof top vents....no pressure build up unless vents are blocked

Have done the extra valve on past 3 trailers for over 15 yrs.

I have not had any issues.
I have not had any backup problems
AND I don't even pay any attention to the tank level monitors.

I do know/understand how my waste tanks function/are plumbed and how long I can go before needing to dump.


'old adage'
When toilet burps...time to dump
When sink/shower start to drain slower....time to dump
When water pump goes burrrrup...need more water


YMMV......

Do you know where (height) the various tanks are located? Most dropped frame units have a black and a grey in the dropped area and the third (or more) grey is located in the upper frame area. If you use a Valtera gate valve to equalize the upper and lower grey you might be asking for trouble. Simple physics say liquid will flow to the lowest point (the grey tank in the dropped frame area) until it is completely filled, then it will back up into the upper grey tank. Which is fine in concept. But in reality the pressure of a full tank plus the pressure from the upper tank is likely to pop the top on the low bid tank used by many manufacturers.

Bought a Valterra 3" dump valve assembly (flanges/valve)

I have a 4' horizontal run that makes a 90* to exit so I cut the drain pipe close to 90* elbow and glued in the new valve assembly.

Added a extra brace using 'plumbers tape'---metal strap with holes.
Wrapped it around pipe with rubber strip and then bolted to underside using self taping screws.

Old-Biscuit wrote:
I have three tanks...black, grey and galley
Black and grey are good size ----galley is 28 gal

All three drain into a common drain header so I permanently installed another drain valve in that common header.
With it closed I can open grey/galley drain valves and increase my grey waste capacity.
I can open all three tank drains valves ----black, grey & galley and really increase my waste water capacity

And after dumping black tank I can close the 'extra' valve.then open grey/galley and backflush soapy grey into black tank then dump


Plus with the extra valve I get no surprises when I remove drain line end cap unless extra valve is leaking.

Did the permanent install because I didn't want the extra weight of the twist on valve hanging on end of drain pipe while traveling OR having to install/remove/store when I want to use it.

VERY good advice. I may have to see about doing that. I have 3 tanks as well- with 3 valves.

I like your reply and explanation Old-buscuit. I have a twist on valve.will try that first. If that works out will try attaching a permanent valve.

I have three tanks...black, grey and galley
Black and grey are good size ----galley is 28 gal

All three drain into a common drain header so I permanently installed another drain valve in that common header.
With it closed I can open grey/galley drain valves and increase my grey waste capacity.
I can open all three tank drains valves ----black, grey & galley and really increase my waste water capacity

And after dumping black tank I can close the 'extra' valve.then open grey/galley and backflush soapy grey into black tank then dump


Plus with the extra valve I get no surprises when I remove drain line end cap unless extra valve is leaking.

Did the permanent install because I didn't want the extra weight of the twist on valve hanging on end of drain pipe while traveling OR having to install/remove/store when I want to use it.

Think I'll try the twist on valve method. Hopefully the tanks will equalize.

I've heard of some people installing a twist on valve where the cap is, and then opening both gray tanks to combine them. Just be sure to close them before you dump the black water, and then use them to flush the black water out of the hose.