I need help with Valves (Soleniod pinch)

[Nathan]

This is the most relevant forum section I could find. Should have said help finding valves... I'm looking for cheap (OEM) NC solenoid pinch valves for silicon tubing of about any (smaller) size for a personnal project. I've spent quite a bit of time looking on the 'net and almost everything I find is designed for medical or scientific research = big money :(. Need minimally 16 - don't need anything to handle extreme pressures, temperatures, etc. Seems like they should be cheap! Typical best deal on 3/8" valves that I find are > $50 each. They don't appear to be more than a $1 solenoid, a spring, and a piece of plastic. I'd be super-duper-duper excited to find some at around the $15 price range. Any ideas? TIA Edited November 19, 2006 by Nathan

[gravitar]

When you say "pinch valve", what do you mean? Are you talking about something that puts pressure on the outside of a piece of tubing to close it off? I've never seen anything like that used in industry. Every valve I've seen has a solenoid-driven metal "spool" with seals, inside a bored metal block. The solenoid drives the spool one way or another, diverting the air to various ports drilled into the metal block. I haven't priced out valves lately but $50/ea sounds about right. Have you looked on ebay? pneumatics seem to go for dirt cheap on there for some reason. You might get a nice, big valve stack for under $50!

[Nathan]

I'm not surprised that you guys had never heard of solenoid pinch valves - I hadn't either until recently. They are an incredibly simple device. A spring forces the tube closed via a little plastic piece. The solenoid opens the valve. That's it! I can buy the same solenoids for $1. Not much use for them in manufacturing. They seem to be used in research labs and for medical apparatus. The point is that you can have a sterile liquid never touch anything but the tubing. When I said $50, that's the very cheapest that I can find any in bulk. Makes sense if you have pressure requirements, but this is a VERY SIMPLE device and I will probably need a whole slew of 'em. This link is a "nicer" one... http://www.clarksol.com/html/prodspecsPK_Valve.htm No luck on ebay. Only solenoid pinch valves are larger than I need and designed for NOS system. Thanks for the input. Edited November 19, 2006 by Nathan

[gravitar]

Interesting idea. But according to their specs, it has a max. pressure rating of 0.5 bar.. Not of much use in an industrial envoronment!

[jstolaruk]

Pinch valves are also popular for applying glue and any time you want to control the flow of a fluid but don't want the control system to touch the fluid. I did a search also and couldn't find anything less than the $50~$60 range. I remember a buddy of mine was using them in his homemade beer making operation but still the cost was higher than what you were hoping for.

[Nathan]

jstolaruk, This is for an appliance project similar to what your friend was doing. Does anyone have OEM/Distributer contacts who might know who to get these things from a little cheaper - I'd probably be in for 100 or so. The silly things should be so cheap...

[gravitar]

I'm sure the manufacturing costs ARE cheap. But given that these are designed for medical applications, I'm sure $25 of every $50 valve goes to a legal department :)

[jstolaruk]

A lot of 100 valves may allow you to bypass the distributor right to the mfg, or at lease get you a healthy quantity discount. I think to release the cam-lock or drawback the spring that is used to pinch tubing to stop flow may take a pretty good healthy sized solenoid, that maybe the reason for the cost.