valve for dumping fresh water

[1940 ford]

I would like to dump the fresh water tank and cannot find the valve. I'm sure it is in plain site. Please advise
Thank you Bob

[JimM68]

They are not always in plain sight...
But they are usually white PVC, 1 or 1 1/2", with a fairly big gate valve
Our Monaco has it on the floor of the plumbing bay.
PaceArrow gasser we used to have, the tank was midships above the frame, the drain was on the back of the tank. To access, you had to pull a velcroed on panel in the basement!

[Beacher]

You can't see it but its on the left side in your sewer bay in the back on the floor black handle

[RJay]

I open the cold water low point valve and start the water pump making sure the cold water supply valve is closed.

[1940 ford]

Thank you for your help. It was right were you said. Our stuff was hiding it.