Ball valve for auto draw off

[TonyL]

I'm building an auto draw off system and I'm struggling with the motorized ball valve. I've had two, and both have stuck closed, the first one to the point of letting the smoke out when it tried to open. Yesterday was the first boil with a replacement valve, (same type as before), and it functioned twice before it refused to open. I'm using 3/4" stainless, 24 volt ac, Ehco-tech valves. They are rated for the heat, I don't know if the viscosity or stickiness of the syrup is the issue.

Can someone with a factory made draw off get me a name of your valve? I need to source one that has a better track record of working on auto draw off systems. Thank you!

[Biz]

You might try contacting Marcland. http://marcland-usa.com.
I spoke to them recently and they have a stronger actuator motor out now that might help. They use 1" valves but I believe the motors are interchangeable so you might be able to replace just the motor part if you can get it.

Dave

[ecp]

most of them are using Belimo by now.

[DrTimPerkins]

Possible that the ball is heating up and expanding, but the housing is not, which makes it harder to turn the ball. Seems unlikely that just a couple of cycles would make the ball so sticky (or coated with niter) that it wouldn't turn, especially if it is hot. More likely the ball is expanding or the motor is too small or the electronics can't deal with the heat. Will the one that hasn't "smoke" open again after you clean it? Maybe try it with cold water and see if it fails or works? Either way...sounds like it's time to try something different.

For smaller auto-draw systems an on-off solenoid valve is pretty common. They will tend to niter up over time, so need to be cleaned or soaked in permeate or condensate periodically to dissolve the scale. Larger evaporators tend to use motorized ball valves, which allow partial open-close.

[Pdiamond]

I have a Smoky lake auto draw system and I had that happen once. I placed a couple of pieces of ceramic blanket in between the area of the evaporator and the valve to keep the heat off and that really did the trick, never had it happen again.

[darkmachine]

I use a 1" us solid valve from Amazon, a laptop power supply to open the valve @ 20vdc. The only trouble I have is mid season if the valve is cold, then it's slugish. I clean with hot water then.

[TonyL]

Thanks for the suggestions everyone! I opened up the latest failed valve today, it was identical to the earlier failure. I have contacted the manufacturer, and will report back when/if I get a response. At this point, I feel a more robust valve is in order.