vacuum pump recomendations

[mntapper]

what is considered high vacuum? I am planning putting my sugarbush on vacuum 100 - 150 taps max, the tubing will be brand new, i will be using an old milk releaser was wondering if this will work for high vacuum? will an old dairy pump create high vacuum? if not what type pump do you recommend? i have electricity(single phase 240 volts) at the sugar shack that is where the pump will be?

[Haynes Forest Products]

Dairy pumps are regulated down to pull 12-15 HGs for the health of the cows. I consider that low vacuum. High vacuum in my opinion is 22-28 HGs. You will never pull 30 HGs and maintaining 28 is tough. My woods generally maintain about 26 and that changes during the day as temps and sap flows help or hinder the vacuum levels.

[DrTimPerkins]

My woods generally maintain about 26 and that changes during the day as temps and sap flows help or hinder the vacuum levels.

The slight drop (less negative....bad) in vacuum during flow periods are probably a result of the increased gases (mostly CO2) being produced by the tree due to higher metabolism as the wood temperature increases. Then, as things cool down again, the vacuum level comes back up (more negative...better).

[brookledge]

mntapper
Looking at the amount of taps you have I would recommend a used dairy vac. pump and a small releaser. Start off with low to medium vac with the amount of taps you have.
The reason I say this is to buy a liquid ring pump to run high vac like 26-27 the cost are very high for 150 taps. Your payback will be a long time. A used 3HP vac pump and releaser will be some where around $3,000
Dairy vac pumps are good to run around 15" without getting to hot. Anything over that they require additional methods for cooling
Keith

[Haynes Forest Products]

I guess I missed the elec part. Having power makes it a snap. Get a Gast dry vane pump they can keep good vacuum levels and will not overheat when things freeze up. Add a timer and they are worry free. It doesn't take much of a pump for 150 taps. Having a good tight system is the main thing. I recommend you spend the money on a releaser that will last a long long time if serviced regularly. Get one now and don't look back.

[Gary R]

For that amount of taps I'd recommend the 3/4 hp Gast dry rotary vane pump. Get a good one off of Ebay, a hobby releaser and you'd be running about 23" for under $1000. I ran a Gast 2567, 1 1/2hp, lubricated. It ran over 27". A couple of times it ran for a week straight. Remember, for every inch deeper in vacuum, about 5% more sap. If you go real deep in vacuum, you'll probably have issues using a dairy releaser.