I'm considering installing a twist on waste valve. When I went to dump the black tank on our last outing the dump handle came off in my hand. It was a bit of an effort to thread it back in place because the end was tucked up under the coroplast. I put a little blue thread locker on the threads when I got home to insure it doesn't happen again. I've read of others that have lost them on the road while travelling.I'm thinking of installing a twist on waste valve and leaving the black tank valve open. The 1-1/2" outlet for the grey tank connects to the common outlet. I will leave the grey valve closed until the black tank is completely emptied. Once the black tank is emptied I'll dump the grey. I always dump the grey first anyway.Any reason I shouldn't do this?

The only negative I can think of is the valve getting whacked by road debris and breaking off. More negative for the drivers behind you.With a third valve, you can use the gray water to backflush the black tank. After dumping the black tank, leave the third valve closed and open the gray until the flow stops. Close the gray and open the third valve. I do the same thing, except I just hold up the slink.

Will the twist-on valve hang down where it could be subject to road debris damage? Other than that possibility, it should work fine. Replacing the existing valve is usually not a big job though, just time consuming.

Dutch_12078 wrote:Will the twist-on valve hang down where it could be subject to road debris damage? Other than that possibility, it should work fine. Replacing the existing valve is usually not a big job though, just time consuming.I don’t think it should hang down but I’ll check before I install it.Don’t enjoy laying under the trailer trying to do repairs, especially if it’s raining. I just want to dump the tanks and go.Thanks for your reply.

We've had one for years; the latest a Valterra. Sometimes our shower gray tank fills up while the kitchen gray tank is almost empty. When that happens the 3rd valve can be shut and the two gray valves opened to `balance' the tanks until the next dumping.I'm still pondering whether to leave the black tank valve open all the time.

Twist on waste valve? | Good Sam Community

jplante4
Explorer II
Oct 04, 2017
The only negative I can think of is the valve getting whacked by road debris and breaking off. More negative for the drivers behind you.

With a third valve, you can use the gray water to backflush the black tank. After dumping the black tank, leave the third valve closed and open the gray until the flow stops. Close the gray and open the third valve. I do the same thing, except I just hold up the slink.
Dutch_12078
Explorer II
Oct 04, 2017
Will the twist-on valve hang down where it could be subject to road debris damage? Other than that possibility, it should work fine. Replacing the existing valve is usually not a big job though, just time consuming.
grampscamper
Explorer
Oct 04, 2017
Jplante4, thanks for the tip.
grampscamper
Explorer
Oct 04, 2017
Dutch_12078 wrote:
Will the twist-on valve hang down where it could be subject to road debris damage? Other than that possibility, it should work fine. Replacing the existing valve is usually not a big job though, just time consuming.

I don’t think it should hang down but I’ll check before I install it.
Don’t enjoy laying under the trailer trying to do repairs, especially if it’s raining. I just want to dump the tanks and go.
Thanks for your reply.
Dick_B
Explorer
Oct 04, 2017
We've had one for years; the latest a Valterra. Sometimes our shower gray tank fills up while the kitchen gray tank is almost empty. When that happens the 3rd valve can be shut and the two gray valves opened to `balance' the tanks until the next dumping.
I'm still pondering whether to leave the black tank valve open all the time.
rhagfo
Explorer III
Oct 04, 2017
Well, to the OP, sounds like you fixed the problem, I would keep the valve closed.
djousma
Explorer
Oct 04, 2017
jplante4 wrote:
The only negative I can think of is the valve getting whacked by road debris and breaking off. More negative for the drivers behind you.

With a third valve, you can use the gray water to backflush the black tank. After dumping the black tank, leave the third valve closed and open the gray until the flow stops. Close the gray and open the third valve. I do the same thing, except I just hold up the slink.

The only problem I can see with this plan is if you do full hookups. When I am on full hookup, I leave the gray tanks open. You certainly wouldnt leave your black tank open too? I also have the twist on valve, but thats because the remote valves always leave a little bit of water in the drain between the valve, and the end, and I dont want a handful of water when I pull the cap.

Maybe you don't do F/H, so it wouldnt be an issue for you.
jplante4
Explorer II
Oct 04, 2017
djousma wrote:
Maybe you don't do F/H, so it wouldnt be an issue for you.

No, I do FHUs but if I leave the gray open during the week, I'll close it the last day or two to build up some flush water.
4x4van
Explorer III
Oct 04, 2017
jplante4 wrote:
djousma wrote:
Maybe you don't do F/H, so it wouldnt be an issue for you.

No, I do FHUs but if I leave the gray open during the week, I'll close it the last day or two to build up some flush water.

The OP would no longer be able to do that if they leave their black valve open and instead use the twist on valve.
grampscamper
Explorer
Oct 04, 2017
I use FHUs but never leave my gray valve open anyway. I may try the twist on valve and see how it goes.
4x4van I like your signature. I hope I never have to stop playing!!

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