Join Date: Nov 2002
Location: Joplin, Missouri USA
I had a very similar problem. It sounds like you may have your problem fixed but here's a quick story just in case...
In my case the needle valve screwed into the outlet of the solenoid. After the solenoid was on for a while it got very warm. This heat flowed through the metal to the needle valve, heating it up too. As the needle valve got hot, the metal it was made of expanded. This changed the very tiny clearance between the needle and the valve seat and shut off or greatly reduced the CO2 flow.
So I'd open the valve to restore the flow.
The pH would drop and the controller would shut off the solenoid. The solenoid and needle valve would cool off. This again changed the clearance between the needle and the valve seat as the metal cooled and contracted.
Next time the controller turned on the solenoid... WHOOSH! The CO2 flow was way to fast when things were cold.
I fixed my problem by getting an in-line needle valve and putting it in the CO2 tubing several inches away from the solenoid (and the heat). The flow regulation is now consistent no matter how hot or cold the solenoid is.
Just something to think about...
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