Black water valve leaking, NOT a simple valve replacement

[VaMark]

I recently purchased a fw camper and found out the other day that my black water valve had a slow drip. I looked at it closer to see the bolts that hold the valve to the flange, which is glue to an elbow, has 2 of the 4 mounting tabs broken off. Its the 2 bottom bolt tabs, the bolts are very badly rusted and have cracked the tabs off and the holes the bolts go thru in the valve are busted also. I don't know where to start..... It looks like the 4 bolt flange that the valve bolts to is glued to the elbow so I can't just cut it out and glue a new one in.
Am I going to have to replace the tank????
Do they make any kind of rubber adapter to go over the elbow and the connect to a new valve mounting flange?
I have a plastic welder and can use it pretty good, I was thinking about cutting out the old valve and welding a new one to the elbow.

Any thoughts?
Anyone had this happen to them?

Thanks in advance for any help you can offer.

Mark

[Chris_Bryant]

I have made flange reinforcements before out of a bit of flat aluminum stock- cut out the pipe radius and the two mounting bolt holes.
Not a good description, but it works fine when you simply cannot replace the fitting.

[VaMark]

Thanks for all the replies. The first thing I am going to try is to weld pieces of ABS material onto the fitting where the bolts go thru and tap threads in it and bolt it together that way. If that doesn't work I am going to try cutting and removing the old valve assy. from the pipe, by chisel or special tool, then glueing a new one on.

[opnspaces]

Can you cut off the elbow and the valve? Then just rebuild with a new elbow and flange and a new valve.

[We_Cant_Wait]

Go to your RV supply center and buy a shut off valve that is part of and assembly that just locks on to where your hose would. Then if the black valve leaks so what you have another valve in line before you uncap and connect up your hose.

[SDcampowneroper]

Mark,
Bladex valves are a simple change out. Do you see a leak on the flange to pipe it bolts to? If so, grind the area clean with such as a Dremel, wash with acetone, repair with pc 7 or 11 epoxy putty. Every good hardware store has it. Works wonders on pvc/ cpvc/ copper pipe.
Pipe to tank connection requires welding, as polyethylene will not glue. ( you know that)
You can carefully cut off the 4 bolt flange with a dremel and propane torch and glue on a new one.
Max

[Tom_Barb]

I'm hoping you have enough pipe between the elbow and the tank to replace the elbow and valve.