The Poorer Man's Diaphragm Pump Vacuum System

[Cedar Eater]

I am testing a smaller cheaper diaphragm pump for use as a mechanical vacuum pump on a 3/16" sapline that is nearly level and has 28 taps. It is a two chambered 12 VDC pump with 3/8" hose barb fittings. It's too cold here to install it yet, but the forecast for late this week or early next looks good. I bought two pumps, one from eBay for around $15 and a Favson from Amazon for around $26. I discovered that they are identical in all observable respects except their labels and packaging, so I decided to only test the cheaper one. This is a pic of the two pumps next to a Shurflo 4008, which is a four chambered pump.

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Here is a pic of the test setup.

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The pump initially only drew a vacuum of 5" Hg, but as soon as it got a little water into it, the vacuum jumped to 17". When I pinched down on the valve that will become the bypass line, the vacuum jumped to 25", which is better than I expected. It's going to be interesting to see how it performs in service. If the motor and pump last the rest of the season I'll be happy if they last through next season, I'll be really impressed. If either fails, I'll report that. Unlike the Shurflo, the motor is not enclosed, so I will be enclosing it to protect it from rain and snow.

[mspina14]

Neat.

Let us know how it works out.

Mark

[littleTapper]

Cool! Looking forward to some data. I've got a "remote" 6 taps at my mother-in-law's and 10 box elder taps that a full-blown 4008 setup would be total overkill. Really curious how long it'll run on a deep cycle battery.

[Cedar Eater]

I got a pair of the smallest cheapest deep cycle batteries I could find, in keeping with the cheaper-is-better approach to the experiment. $60/ea. I do plan to report on how it goes. I've heard these pumps fail quickly without a strainer up stream, so I found a cheaper-than-Shurflow 50 micron strainer that also has 3/8" hose barb fittings.

[Ghs57]

This should be very interesting.

[sugarsand]

Where did you find the cheaper strainer filters? We started using these ebay cheapies last year, still running strong this year. The pumps are all 4L/m and draw about 1.1 amps an hr, which if I understand it right, a 12amh battery should last10 - 11 hours. These pumps will generate more sap at a cheap cost.

[Biz]

I just ordered the same Favson pump yesterday to experiment with. Might not get to do much this year with it, but I will have 4 short 3/16" lines next year that are too far apart use one pump on, so I could have 4 pumps out there, 20-40 taps each. I will still use my controller unit but maybe scaled down. It will be a fun experiment.

Dave

[wmick]

When I pinched down on the valve that will become the bypass line, the vacuum jumped to 25",

Can you clarify what you meant by this??
Just trying to learn a little bit about these pumps and setups.. Might decide to throw one together at the last minute.
and how are you planning to connect this? ..... just connecting the inlet to the sap line and the outlet to your storage tank??? or ??? What is the "bypass"?

Thanks

[Cedar Eater]

Where did you find the cheaper strainer filters?

I got it from Amazon. They are currently unavailable from them, but you might be able to go directly to the manufacturer to find another supplier. https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[Cedar Eater]

Quote Originally Posted by Cedar Eater
"When I pinched down on the valve that will become the bypass line, the vacuum jumped to 25",

Can you clarify what you meant by this??
Just trying to learn a little bit about these pumps and setups.. Might decide to throw one together at the last minute.
and how are you planning to connect this? ..... just connecting the inlet to the sap line and the outlet to your storage tank??? or ??? What is the "bypass"?

Thanks

The bypass is a line that you drop down from the intake side of the pump into the collection tank or route over to the discharge side of the pump to allow a little liquid to be drawn back into the intake side of the pump to keep the diaphragms wet. The diaphragms suck harder when they are wet. But obviously, you are decreasing the efficiency of the pump by repumping previously pumped sap through it, so you want to minimize that which maximizes the suction. Closing the valve to allow the bare minimum of repump flow does that for you. A needle valve would have been better, but I couldn't find one at the hardware store that had pipe threads or hose barbs, so I used a ball valve. I will insert a 3/16" tee between the valve and the vacuum guage tee and then bring the sap line into the third port of that tee.