Dumping black and gray water question

[jkmcbride54]

How many release valves does a 2009 keystone Cougar 318SAB have?
I located two but many other keystone 5th wheels have three. One for the black water, one for gray water, and one for the galley. I can't seem to locate a third release valve. I even looked between the tires as some located it between the tires. My concern is that the release valve handle and rod are broken off but I'm only guessing.
Thanks in advance for any insight to my question.

[BFlinn181]

Are you sure the kitchen sink doesn't drain into the grey tank? If you dump the grey tank then run water into the sink, does it not show in the grey tank? Rather than tear things apart looking for a third tank and dump valve, verify if you only have one grey and one black.

I don't know about 5th wheel trailers, but some Class A RVs have the grey tank collect from the kitchen sink and shower(tub) and the lavatory sink drains into the black tank with the toilet.

[Bob_C]

If your tanks are empty, add different color food coloring in the sinks, then open one valve at a time to see what color appears...

[bddadles]

Put a clear connector on the sewer connection so you can see the running water. Drain the grey tank. Now turn on the water in the galley. If you see water draining you have the galley valve. After the water stops appearing tuurn on the bathroom water. If it appears again they are both draining into the same tank and you only have 1 grey dump valve.