Hello looking for a valve arrangeme

[Bisonman]

Hello looking for a valve arrangement to reduce city water pressure from 100 or less psi to 20 psi then to stop the flow then be able to draw a vacuum of 10-20 inches but then stop the flow when the vacuum stops? It has to be done all mechanical!

 

[1503-44]

A pressure regulator can lower the city water pressure to 0 psig, but that's not a vacuum.
How are you planning to create this vacuum? Vacuum from where, or with what?

 

[LittleInch]

And 10 to 20 inches below atmospheric pressure or 10 to 20 inches absolute pressure?

How many times?

Most regulators have difficulty sealing on a regular basis. And all mechanical? Going to be difficult

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Bisonman]

Hello, the vacuum pump is our stainless steel hand water pumps they would be drawing a vacuum on the outlet side of this arrangement. I know this is where it just tricky to stop the flow when the pumping stops and then start again when the pumping starts? I know I can do this possible with a electric switch but I have to do this all mechanical and that is where I’m stumped!

 

[1503-44]

You shouldn't expect a control valve or regulator to seal tightly enough to do vacuum work. I'd suggest you put an additional tightly sealing electric operated valve that will be either opened or closed after the regulator. Do your vacuum work downstream of that.

 

[Compositepro]

Unless you have some special requirements for precision, a simple pressure regulator with the correct range should work fine for supplying hand pumps. If the regulator leaks a tiny amount, the dispenser pump will drip slightly. No different than a faucet.

 

[Compositepro]

Another option would be to use a float valve to maintain the level in a small tank, and pump from that.

 

[Bisonman]

Thank You for your reply’s but a tank is not what I’m trying to accomplish for this application! I do use a tank for some of our application so thank You!