Grey Tank Equalization concern

[Dale B]

Having 2ea Grey Tanks, I learned from this forum(not the owners manual) . One is for bathroom shower & sink, the second for the Kitchen sink, no cross flow between the tanks. Learning from the forum I installed a gate valve @ the end of the sewer drain. Then I should be able open to both Gray tank drain gate valves & the levels should equalized.

I tried this today & the results are not as expected, one tank was 2/3's the second was 1/3. Now, one tank indicates full & the other is empty. I don't think this is a good thing, or will the water start to fill the empty tank.

Has anyone seen this & what have you done?

Initially I wondered about the elevation of the tanks & would they be the same. My guess would be low in the frame, maybe not, maybe the bathroom is higher.

Thinking out loud if the trap for the kitchen sink is above the tank it should equalize.....me thinks

[Country Campers]

What I am thinking, and should have thought before, is that the Solitude and Momentum lines have a drop frame. The front portion of the frame, ahead of the door, is lower than the rear portion, door back and above the axles. This wold put the black and grey tank for the bathroom on a lower level than the grey tank for the kitchen. From your description I would guess that the 2/3 tank was the bath grey and the 1/3 tank was the kitchen, when you tried to equalize the bath grey became full and the kitchen grey became empty. With a standard frame or straight frame such as my Reflection fifth wheel all tanks are on the same level , as well as the TT lines, which would in theory provide for the equalization to work.

Brian

[Dale B]

What I am thinking, and should have thought before, is that the Solitude and Momentum lines have a drop frame. The front portion of the frame, ahead of the door, is lower than the rear portion, door back and above the axles. This wold put the black and grey tank for the bathroom on a lower level than the grey tank for the kitchen. From your description I would guess that the 2/3 tank was the bath grey and the 1/3 tank was the kitchen, when you tried to equalize the bath grey became full and the kitchen grey became empty. With a standard frame or straight frame such as my Reflection fifth wheel all tanks are on the same level , as well as the TT lines, which would in theory provide for the equalization to work.

Brian

That makes good sense, I'm not aware of the frame & tank placement. I'm sure your description of the kitchen water moving to bathroom gray is accurate. I had not paid attention to which tank is for what, I did notice the gray valves do not indicate which tank.

So in theory as long as the sinks & shower traps/drains are above the tanks & they are, would they not equalize?

[Country Campers]

The traps would not have a bearing on tank equalization, the tanks would need to be on the same level to each other to be able to equalize. I ran water into the bath grey tank to label the pull handles for each grey tank.

Brian

[Dale B]

The traps would not have a bearing on tank equalization, the tanks would need to be on the same level to each other to be able to equalize. I ran water into the bath grey tank to label the pull handles for each grey tank.

Brian

I didn't phrase that they way I wanted to. What I'm wondering is if I would be OK to leave the two dump valves open, the concern would be the shower & sink draining. Because those drains/traps are higher than kitchen gray tank would the water from them migrate through they holding tank drain plumbing & fill the kitchen gray without issue?

I'm I explaining that correctly?

[TucsonJim]

Dale,

I looked at the 310 drawings we have. Although I can see the tank placement from a top view, I don't have a drawing for the side view. All three of the holding tanks are standard HT466 tanks which means they have the same dimensions which rules out different tank dimensional heights. Would it be possible for you to loosen up the underbelly to see the different locations for the tanks in relation to each other?

Jim

[Jlawles2]

Dale B Dale, the question you want answered is which tank is lower, Kitchen or Shower? Yes you can leave the valves open. Will they equalize? Not necessarily. If the shower tank bottom is higher than the kitchen tank top, the shower will overfill the kitchen. If the bottoms are the same, then they will be close or equal.

Does this explanation make sense? Remember water will always try to find the lowest point and work upward from there provided there is a path to the low point.

[Canyonlight]

Dale B - I believe pengle took pictures of their 310 tank placement.....seems I saw the picture elsewhere in the last few days. Possibly you can PM them if they do not chime in.

Dan

[Dale B]

Dale,

I looked at the 310 drawings we have. Although I can see the tank placement from a top view, I don't have a drawing for the side view. All three of the holding tanks are standard HT466 tanks which means they have the same dimensions which rules out different tank dimensional heights. Would it be possible for you to loosen up the underbelly to see the different locations for the tanks in relation to each other?

Jim

I'm not wanting to touch the under belly, unless I have to.

[Dale B]

Dale B Dale, the question you want answered is which tank is lower, Kitchen or Shower? Yes you can leave the valves open. Will they equalize? Not necessarily. If the shower tank bottom is higher than the kitchen tank top, the shower will overfill the kitchen. If the bottoms are the same, then they will be close or equal.

Does this explanation make sense? Remember water will always try to find the lowest point and work upward from there provided there is a path to the low point.

It seems the bathroom tank is the lowest & makes sense according to my tank monitor. There would be a low point path thru the drains, valves open.

[Dale B]

Dale B - I believe pengle took pictures of their 310 tank placement.....seems I saw the picture elsewhere in the last few days. Possibly you can PM them if they do not chime in.

Dan

Tx's for that! I will search for that latter today.

[Jlawles2]

Dale B Dale, if both tanks valves are open along with the discharge hose hooked up and not blocked (no twist on Valtera https://www.amazon.com/dp/B000BGHYJS...refix=valterra valve closed) the system should drain and not back up into the other tank.

If you have an obstruction in the discharge line or have a reduced size discharge hose (https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1), you may have back up into the lower tank. This backup will drain provided the line is not blocked.

Most here will recommend not leaving any valves open as it could lead to infestation of critters through the discharge hose into the tanks or worse the inside of the camper. It is especially critical that the Black tank not be left open as solids can build up leading to issues in tank.

[pengle]

Tx's for that! I will search for that latter today.

I may have posted the picture on "the other forum". Here are a couple of pictures that show the orientation of the three tanks. I think the height of the tanks at the outlet end are 8 3/4". The bottom of the kitchen tank is at least 3" higher than the bath tank AND the outlet pipe from the kitchen tank is angled up ANOTHER 2". The picture of the outlet of the kitchen tank with the gate valve is deceiving because it looks like the reducer from 3" - 1 1/2" is at the top. I have another picture that shows that it is indeed oriented at the bottom of the tank opening.

[Country Campers]

I would think that according to the pictures trying to equalize these tanks would lead to grey water backing up into the shower before or shortly after starting to fill the kitchen grey, there is also the vent pipe connection that would worry me as a possible leaking area. I think that this is not a good idea to try to equalize these grey tanks.

Brian

[Dale B]

I would think that according to the pictures trying to equalize these tanks would lead to grey water backing up into the shower before or shortly after starting to fill the kitchen grey, there is also the vent pipe connection that would worry me as a possible leaking area. I think that this is not a good idea to try to equalize these grey tanks.

Brian

Your thought process is the title of my thread & the reason I've brought it up @pengle your photo's are worth a thousand words & helps visualize the risk factor of leaving the two gate valves open.

Necking that 3" drain down to 1.5" is the one that concerns me when the full bath tank attempts to drain back & up into the kitchen tank.

I have the valves open right now, I may just & run the shower & see if I can get a reading on the Kitchen gray. My guess is that yes the shower will begin to back up @ which point I will stop, then slowly the levels will equalize. That 3" drain to 1.5" is what will slow the process down....me thinks.