Gravity Fed (Water release) Solenoid Valve not feeding water without pressure being applied 2

[baashwell]

Hello all,

I have a bottle of liquid passing through an electronic water release valve, the particular valve should release liquid with gravity pressure alone however when opened no liquid comes out. When I squeeze the bottle on top lightly the liquid comes out of the valve (and stops when valve closes).

Any idea how I can 'loosen' the valve so it requires less pressure or have any idea on another piece of equipment I can use to do a similar job?

Many thanks,
Ben

 

[moltenmetal]

You need a direct acting solenoid valve. What you have sounds like a pilot-operated solenoid valve, which requires differential pressure between the inlet and outlet in order to open.

Direct acting solenoid valves have a mechanism which is entirely operated by the solenoid coil. These valves are therefore bidirectional and don't rely on differential pressure in one direction or the other to open or close. But of course they have larger, higher power solenoids for a valve of the same size as would be required for a pilot operated valve.

 

[LittleInch]

What is an "electronic water release valve?"

Please advise model and manufacturer otherwise w have no idea what type of valve you're referring to.

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

 

[gerhardl]

Hello, Bashwell!

Agree with both postings above, let me try to expand a bit on the two points:

1. As Moltenmetal points out: Most likely you do not have a direct acting solenoid, or also maybe a solenoid valve with forced lifting 'said' to act from 0 bar, but in reality requiring an extra push. Several solutions may be found, best is to change to proper type. (How much pressure do you need? 0,1 bar: move bottle 1 m up from inlet. 0.5 bar and 5m would not be practical.) Does not seem that clogging is a problem in your case.

2.As LittleInch points out: Giving exact identification will make it easy to comment on problems for your application. Also note that opening and closing time probably will be important for you. Also checking cv - value is important, including the used manufacturers definition for cv, it might vary for solenoid valves. Compare with value for existing, which seems to be OK (???) Also note that the real netto opening is not the same as the nominal connecting diameter for a solenoid valve, a 1/4" solenoid valve might have bore at 1-2mm or less. The problem in your case might be added to with a too small bore.

Good luck.

 

[baashwell]

Thanks for the replies, the valve I am using is something cheap picked up off Ebay just to try out, linked here:

http://www.ebay.co.uk/itm/Electric-...535873?hash=item3aa1ac7041:g:aaUAAOSwNSxU-AzK

I am not 100% sure if this is a direct acting solenoid valve but it doesn't mention anything about needing a pressure differential, just that the minimum pressure needed is 0.02Mpa which hopefully a bottle of liquid would be creating. I have also thought maybe as I am not bleeding air into the bottle attached to the solenoid this may be causing the issue. If you could let me know if this is a direct acting solenoid that would be much appreciated, and if it isn't if you could point me in the direction of one?

Thanks again everyone,
Ben

 

[moltenmetal]

And the lesson is, read the technical description before you buy stuff!

It says quite clearly:

- valve type: diaphragm (operated by servo) Servo = pilot operated!
- NOT SUITABLE FOR USE IN GRAVITY FED SYSTEMS!

Throw the valve away, and buy one which is direct acting. And yes, you DO need a means to admit air to replace the water you've drained out. That can be provided by means of additional ports on the same valve (if intermittent draining of small volumes is required), or may require either an open vent or a similar direct-acting solenoid valve.

 

[gerhardl]

That's it!

 

[monkeydog]

You cannot make this stuff up!!!

 

[baashwell]

Well that explains that one, like I said was just messing around with these, hopefully now I'll get it working.

Thanks for the useful replys