Mechanical releaser and high vacuum

[Mark]

Does anyone use a mechanical releaser at 27 inches vacuum? Do you have any problems with the float rods freezing up with the small amount of air leaking around them? I have an electric Bernard at a remote pump station and have been thinking of going to a mechanical releaser.

[maplecrest]

ice starts to build up on the metal rods and grows till the rods cannot go up and will break the cover on a double. and just not work on the horizonal. i have used the r/o grease around the rod and does help for a while. or you can sit there and trip the releaser

[sweetwoodmaple]

This is where using electric floats and solenoids would really shine. My mechanical/electric releaser has no issues with high vacuum.

It's just the power requirement that's a pain. All depends on the set up if you can run power. It only takes a few amps to run both solenoids.

[Mark]

mechanical/electric releaser sounds interesting, I have not seen one before. Do you have a picture of it?

[sweetwoodmaple]

Mine is kind of embarassing, but it works (built the entire thing myself).

Basically, insead of having the floats inside with rods, you have an upper and lower float switch. You use those with some relays and two solenoid valves to control the vacuum release and switch over between the small and large tank of the releaser.

There is a thread for a homemade releaser if you want to look there.

[gmcooper]

I have a machanical releaser with a liquid ring pump. I can run about 25" if I pay attention to leaks. Have been at 27" a few days. With my old CDL reaser it would freeze up frequently as I was getting air leaks around the rods in the releaser. Put in a new Laperrier 2 years ago and no freeze ups yet. A leak way up in the woods doesn't seem to affect the releaser much but a small leak at the releaser or close was a big issue with freezing up.

[DrTimPerkins]

....Have been at 27" a few days. With my old releaser it would freeze up frequently as I was getting air leaks around the rods in the releaser.

At those vacuum levels, the freezing point of the water vapor increases due to the low vapor pressure -- kind of like "carb icing" on an old car or airplane (it is still a real issue in piston airplanes...you need to use carb heat to prevent it if you have high humidity anywhere near freezing) If you keep the releaser in a heated space and keep it well oiled it will help. Running at high vacuum definitely causes lots of issues to crop up. The equipment just isn't designed to run at those vacuum levels....but it is getting better each year.

[Mark]

I might stay with my electric releaser and go with a Grundfos CRN Mag-drive that has no seals and conductive rod level switches.

[chipa]

Those pumps look pretty expensive.

[Mark]

A little problem can cost a lot more than that.