Electric grey waste valve

[Jofang]

We arrived home after a long weekend away and pressed the switch to open the grey dump valve and nothing happened, so here we are with a tank full of grey waste wondering what to do. Fortunately, I have a very small water pump, such as you'd find in a toilet flush, with a long extension lead so I set about emptying the tank from inside the motorhome. Subsequent to this I researched the offending valve on the internet and find that it has a small knob, which is slightly larger than a shirt button, on the face of the electric part of the valve. This knob operates the valve manually, so by turning it I was able to open the valve. The valve is located in an impossible to reach location unless you have 10 inch fingers, so I decided that replacement was not an option for DIY. I subsequently fitted a manual valve on the end of the grey plastic drain pipe and have left the electric valve open but inoperable. My question now is how many turns of this knob are required to open the valve fully? 1 or 10 or 20 turns, or does the knob keep turning indefinitely when the valve is fully open and likewise to close the valve also?

 

[Spriddler]

My question now is how many turns of this knob are required to open the valve fully? 1 or 10 or 20 turns, or does the knob keep turning indefinitely when the valve is fully open and likewise to close the valve also?

Why not put some water in the tank and see what happens when you turn the knob?

 

[Jofang]

Thanks for your response. I have done exactly as you say but I'm conscious that I don't want to turn too much and break something versus not turning enough, leaving the valve partly open and a potential trap for a blockage.

 

[berni109]

I think most grey water valves are of the ball valve type turn 90° closed to open.
The manual one on my van is and so is the electric one that I am still intending to fit.