Pumping sap from a vacuum container

[ibby458]

I'm hoping to put tubing and vacuum in a 1000 tap bush next year. I have a 30 gallon vacuum tank, and a new 8 roller sprayer pump. If I plumb the pump intake to the bottom of the vacuum tank, will it suck the sap out against the vacuum? I'm trying to get by without a releaser.

[Jonathan Temple]

I would also like to know what pump will pump against vacuume and how it needs to be plumed?

[Smith's Maple]

I'm pretty sure this will not work without a releaser of some sort. I have 700 taps on vaccum.

[ennismaple]

Won't work - the vacuum will pull air through the pump, causing it to turn backwards which is not good for the pump. We turn the vacuum off when we need to drain our Zero tanks. No big deal for the 15 minutes it takes to pump out 525 gallons of sap and wash out the tank.

[Big maple]

You need to put a check valve on the outlet side of the pump and a 1/2 or 3/4 piece of tubing out of one of the drains on the pump towards the top of the tank with a check valve that only allows the vacuum to suck the sap through the pump and up the tube. That keeps the pump primed and allows it to overcome the vacuum.

[802maple]

All you have to do is what big maple said

[ibby458]

You need to put a check valve on the outlet side of the pump and a 1/2 or 3/4 piece of tubing out of one of the drains on the pump towards the top of the tank with a check valve that only allows the vacuum to suck the sap through the pump and up the tube. That keeps the pump primed and allows it to overcome the vacuum.


Could you elaborate on this? Check valve on the sap pump or the vacuum pump? Tube from drain on vacuum pump or sap pump? I don't have a vacuum pump yet, so can;t quit follow.

I did find the correct conversion factor, and discovered you can't draw against more than about 16 inches of mercury vacuum without some sort of device to reduce the inlet pressure.

[NH Maplemaker]

Four both case's they are talking about the sap pump !

Jim L.

[DS Maple]

First of all get a good sap pump that is capable of pulling against pressure. We use a 2" Pacer with a 3.5 Briggs and Stratton engine and it works just fine for pumping out a 1000 gallon Zero tank under 20" of mercury. The key is to start the pump and bring it up to full throttle before opening the valve on the tank. If you open the valve first it will just suck the prime out of the pump and then the pump won't be able to pull anything until you fill it with liquid again. Using this method there is no need for check valves (sometimes expensive,) but I would recommend putting a simple plastic ball valve somewhere on the sight tube if you have one because otherwise the pump will suck air through the tube once the level in the tank gets low and you won't be able to empty it all the way.

[Rhino]

what we are useing for the first year ever is a half horse deep well pump inside our 300 gal. zero tank. its on a float switch and we have it set to pump 30 gal. out at a time. picked up used pump from a local well driller for 100 bucks. since they are high pressure pumps they can overcome the vac. no problem. we do have the float set to leave pump covered to prevent freezing and drying out and getting sticky. wouldnt want to buy new pumps, kind of expensive, but check with the well drillers. mine had a whole shelf of them. good luck

[maplehound]

I too use a deep well pump laid in the bottom of my 300 gallon zero. The outlet comes right out the hole in the lid. Just after it exits the tank I put in a check valvue so it closes when the pump is off and keeps the vaccume in tact. After this check valve I T off with another check valvue straight up and open to the air, so when the pump shut off the first valvue closes and the second opens to allow air into the line and start a siphon down the pump line to my hauling tank, to keep the line as empty as possible.