# Does this exist? -Sliding Fluid Restrictor -Solenoid Valve -Ball Valve

I am trying to come up with a way to restrict beer flow using a valve that does not cause foam. I have found that a solenoid valve causes a change in the direction the beer must flow and this sharp change through a different size opening creates foam quickly. I have thought about a ball valve or pinch valve but I need it to be electric, work very quickly and have a small form factor.

Does anyone know if anything like what I created in this video exist? https://youtu.be/iE6qe7045Ck

The idea would be electromagnets that cause the metal pieces to slide in one direction or the other opening and closing the flow of beer. The idea is keeping the opening in the valve the same diameter as the inner diameter of the tubing I would be using (3/8"). It would need to handle at most 14 psi and at least 12 psi. (Average beer lines are 9-10psi)

• Is an electric connection a negative? You give the electrical requirement as a reason why the ball valve isn't a good fit; then you use an electromagnet as your preferred idea. – hazzey Apr 6 '15 at 12:49
• Thanks for the question hazzey. Ball valves turn or shut off too slowly for what i need. Thats why a listed them as a negative. – Peace Apr 12 '15 at 1:46
• So, how fast does this valve need to operate? I have used actuated ball valves (both electric and pneumatic) that open and close quite fast, but your requirements in that regard are vague. – DLS3141 Sep 24 '15 at 13:45

What you are describing is a gate valve and you are correct in assuming that this would not cause foam. Unfortunately, I do not think that gate valves are manufactured in the small size that you need. If your tubing is 3/8" ID, that is approximately equal to schedule 40 1/4" nominal pipe size. I have never seen a gate valve smaller than 3/4" nominal pipe size.

With that said, if I were trying to accomplish the task you describe, I would find a beer tap and attach a solenoid to the handle.

Look at pinch valves: A small piece of tubing that can be pinched shut pneumatically or mechanically (solenoid). When open, you have the full diameter of your tubing. The only part that touches the medium is the tube, and you don't have any sliding seals. The latter part is important, because you don't want to mess up your beer with sealant grease and you don't want $CO_{2}$ to bubble along the seals. Also it seems you are looking for a DIY solution, so a simple build will be your friend.
I don't know about foaming. You could test by having beer flow through tubing and pinch it with your fingers.

I am not a Mechanical Engineer. But may I suggest a faucet cartridge. Attached are two images. These with a combination of stepper motor might work for you. The cartridges are small and is design to be used with water. Just a thought.

• I don't think this will work very well. 1) it might still cause foaming. 2) how is the OP supposed to connect it to their system? 3) I'm not sure if this will meet OP's requirement of "work very quickly" – regdoug Apr 6 '15 at 16:10
• @regdoug, this was just a thought, I am not a ME, just made a suggestion. – Mahendra Gunawardena Apr 6 '15 at 22:34