Solenoid not closing properly

[SyracusePunk]

Hi all,

We have a solenoid (normally closed) for glycol flow on our bright tank and it is not closing properly once cooling is not longer needed leading to frozen beer.

Does this seem like just a bad solenoid issue? I am able to get it to close properly by shutting down the pump to the coolant ring andcycling the solenoid on and off a few times then turning the cooling back on. Some things i have read suggest that a pressure differential may be the cause. Any thoughts please let me know!

-Rich White
Head Brewer
London Brewing Co.
rich@londonbrewing.com

[ChesterBrew]

Do you have a pressure bypass valve installed at the end of the supply header? Perhaps this old thread may help:

http://discussions.probrewer.com/showthread.php?18311-Glycol-supply-pressure-bypass

[SyracusePunk]

We do have a solenoid at the end of the loop that opens once all other solenoids de-energize. The system runs around 2 bar which is a bit high but our solenoids are rated between 0-10 bar. I'm seeing examples of solenoid that require 25psi in differential pressure to operate but as the return is not pressurized there should be enough of a differential.

[beerguy1]

Same thing happened to me. Hopefully there is a screen to collect any debris if there has been recent work. We had to rebuild the solenoid

[SyracusePunk]

Just ordered a replacment, so am I reading correctly that you had to disassemble and rinse out whatever debris was in there?

-rich

Same thing happened to me. Hopefully there is a screen to collect any debris if there has been recent work. We had to rebuild the solenoid

[Todd Hicks]

Just ordered a replacment, so am I reading correctly that you had to disassemble and rinse out whatever debris was in there?

-rich

It is always good to have several extra solenoid coils on hand. The valve body not so much, and I have only replaced one solenoid valve gasket set in 25 years.

On a new system, you pretty much always have to clean out the solenoid guts after they have been running for a day or two. There is always PVC glue and debris in the pipes to work its way out. Clean them out whenever you add new tanks also.
If that is not the case (which it likely is) then you can also restrict the flow to the valve with a ball valve in front of the solenoid. Note: there should be a ball valve directly before and after the solenoid valve for maintenance and flow restriction. There should be a main shut off valve off of each drop to each tank IN and OUT at the main glycol trunk. Also as recommended there should be a bypass loop valve at the end of the glycol trunk and a strainer somewhere in line right after the glycol pump that is easily accessible.

[Todd Hicks]

Same thing happened to me. Hopefully there is a screen to collect any debris if there has been recent work. We had to rebuild the solenoid

Be careful when taking them apart. Small parts like to fall on the dark wet floor and fall into the drain forever. Small screws, lock washers, springs, ball bearings, o-rings, and diddliedoos. Put it back together exactly, sometimes the diaphragm likes to face a certain way - look to see if it has a tiny weep hole in it. Put it back together exactly.