Ball valve for black tank...Dallas?

[John316]

Howdy, everybody.  It has been a while.

We had to pull our tanks from the bus, since the fresh water was leaking (of course it is behind all of the rest of the tanks). While we have the tanks out we are looking at our dumping system.

Right now we have the standard blade valve. The problem is the valve often allows just a little bit of seepage (because we have it mounted vertically, and not horizontally due to space issues). I remember a while back Dallas mentioned that he used a ball valve.

Here are my questions. Right now we have ABS down there. I believe the ball valve to be PVC. Also what about the connector that has the studs (spikes, bayonets, whatever), so one can attach a drain hose to the pipe. Do they make those in PVC?

Any other ideas?

Thanks a lot.

God bless,

John

[DMoedave]

John, we had ours vertical and it would weep also. I have a cap theat fits the bayonet fittings that has a hose connector on it. I think it was so you could clean the tank from below. Anyway it workied to stop the leakage and made it easy to unscrew and drain.

[JohnEd]

That cap with a garden hose fitting is a "must carry" item.  With the hose capped off it is a regular sewer cap that will hold back  seepage if the cap gasket is good.  You can also connect a 50 ft garden hose to the gray water and dump the grey water 50 ft from the bus....it stinks for a day.  You can also use that garden hose fitting to "inject" compressed air into the black tank to release blockage at the tank outlet.  Not talking 110 psi, just a squirt of air that will travel  up to the tank  where it bubbles the blockage away and they passes harmlessly up and out the tank vent.  can you just imagine not being able to dump and NOT having this option?  Shudder!

Those valves "seep after they get old and a rebuild won't help if the blade has scores and scrapes.  The new ones make a good seal and if they don't return them.  No matter if they are mounted horizontal, vertical or even upside down.   ALWAYS open those valves quickly and fully to the stop or they will accumulate gunk behind the seal and leak/seep.

John

[Sean]

... The problem is the valve often allows just a little bit of seepage (because we have it mounted vertically, and not horizontally due to space issues).

John, if the valve is seeping, it has problems.  It has nothing to do with the mounting orientation -- the pressure on the valve face is related only to the height of the water column behind it, and not to the mounting orientation.  If the valve leaks facing down, it would also leak facing sideways.  The seats and/or blade probably need to be replaced -- an inexpensive kit, and far less expensive than changing to ball valves, which are very pricey in 3" diameter.

Here are my questions. Right now we have ABS down there. I believe the ball valve to be PVC. Also what about the connector that has the studs (spikes, bayonets, whatever), so one can attach a drain hose to the pipe. Do they make those in PVC?

All the Valterra, Camco, etc. RV waste fittings are ABS.  There are ABS ball valves which you can order, but if you want to use PVC, you need to get "transition cement," available in any hardware store and made explicitly for joining PVC to ABS fittings.

-Sean
http://OurOdyssey.BlogSpot.com

[Just Dallas]

Removed