Lunchbox sap pump questions

[DMF]

I am building a couple of lunchbox sap pumps this year and I have a couple of questions. First some details. I am using 5/16 sap line for my air supply line and my shop compressor to supply air. The compressor is a twin cylinder compressor with an 80 (/) gallon tank.

1. How far has anyone run a line to their lunchbox pump? I read on earlier threads when Dean was still around and selling them that he knew of someone running 1/4 mile with no problem. I'm looking at closer to 1/3 mile for my furthest one.

2. In the past, I have run all my lines to a collection area where the grade started to level off. I have several trees to tap below this that slope less but brings me closer to the main road (these trees will be on one separate lunchbox pump). Can I set up a couple of lunchbox pumps where my lines currently end and use the output of my pump to send the sap an additional 300/ (+/-) so all my tanks can be closer to the road?

A friend of mine who has been using these for a few years now thinks it's possible, but my distances for each question are further than what he has done in the past so I was hoping for more feedback. Thanks for the help!

[DougM]

DMF, we have two homebuilt lunchbox pumps at about 1,200' and 1,500' from our air compressor. They both run off the same 5/16" air line, and have separate 5/16" "homerun" sap lines back to the tanks near the compressor. The sap lines run uphill probably 10' vertical over around 500' horizontal, then downhill to the tanks. Not quite the same as your situation, but I thought the distances might be relevant. We have had really good results with this setup, each pump has close to 100 taps, and we get around 15-17" vacuum at the farthest tap. Not high vacuum compared to some setups, but they are really economical for our situation.

We have another setup with 85 taps on a pump at the bottom of a hill, the main purpose of the pump is to send sap about 600' horizontally and about 10-12' vertically to a tank near the road. We originally had this on 3/16" natural vacuum but had trouble accessing the pump in wet weather. With the lunchbox pumping it to the tank next to the drive, we can get to it in any weather.

Good luck,
Doug

[DougM]

I forgot to include that the pump manufacturer recommended that we use inline moisture traps on the air lines near the pumps.

[Vtmbz]

I use a lot of these pumps. On one set of two pumps i run air 500ft. I return sap from about 100 taps 500 ft with a thirty five foot climb over a hill and back down. I once measured how much water i could pump on this grade and found i could send 22 gallons an hour over the hill. This is all 5/16 line btw.

When i clean up in the spring i pump water on my 500 ft line back to that setup, which is the low spot on that area and am able to put water to the highest tap, another 600 feet and another 50 ft high. I just reverse the pumps at the collection point.

I use g80 smoothie pumps.

Interesting about the vacuum numbers. I get about the same.

[DougM]

Vtmbz,
Good point, we use our pumps to flush the lines as well, and on our hilly woods we have (elevation change of around 40' in 550') the pump has no problem flushing the lines.

[Vtmbz]

Vtmbz,
Good point, we use our pumps to flush the lines as well, and on our hilly woods we have (elevation change of around 40' in 550') the pump has no problem flushing the lines.

My rough calculations are that each of these pumps at 60psi will handle about 75-100 taps but what i dont know is the upper limit of an out going 5/16 line. Im running two pumps into one output. Sounds like you run one 5/16 per pump. Is that necessary?

[DMF]

DMF, we have two homebuilt lunchbox pumps at about 1,200' and 1,500' from our air compressor. They both run off the same 5/16" air line, and have separate 5/16" "homerun" sap lines back to the tanks near the compressor. The sap lines run uphill probably 10' vertical over around 500' horizontal, then downhill to the tanks. Not quite the same as your situation, but I thought the distances might be relevant. We have had really good results with this setup, each pump has close to 100 taps, and we get around 15-17" vacuum at the farthest tap. Not high vacuum compared to some setups, but they are really economical for our situation.

We have another setup with 85 taps on a pump at the bottom of a hill, the main purpose of the pump is to send sap about 600' horizontally and about 10-12' vertically to a tank near the road. We originally had this on 3/16" natural vacuum but had trouble accessing the pump in wet weather. With the lunchbox pumping it to the tank next to the drive, we can get to it in any weather.

Good luck,
Doug

This is very helpful; thanks!


My rough calculations are that each of these pumps at 60psi will handle about 75-100 taps but what i dont know is the upper limit of an out going 5/16 line. Im running two pumps into one output. Sounds like you run one 5/16 per pump. Is that necessary?

Very good question, I would like to know this as well.

[Vtmbz]

As i mentioned earlier, i have pumped 22 gals hr. That was using one pump, About 100 taps worth at peak flow.
Outbound pressure would tell something. Specs for g80 say maxiumum input liquid pressure is 30psi.

I also have used two pumps in one line as a booster, but i never felt it was an improvement. Maybe because they pulsate out of sync?

[DougM]

Well, I haven't had to do pressure flow calculations in a long time, and I don't know the actual line pressure but an online calculator I found says a 5/16" line 100' long @ 60psi will flow 243 gph/4gpm or at 30psi will flow 117 gph or 1.9 gpm.
We use two separate lines because we put one pump in with around 100 taps, then the second a year later with about 100. and mostly just assumed that we needed separate lines. So we probably could run them both into one, but we also have to take those home run lines down yearly so we just roll both sap lines and the air line up together on a big cable spool. I don't know if we could do that with a bigger single sap line or not.

[Vtmbz]

Well, I haven't had to do pressure flow calculations in a long time, and I don't know the actual line pressure but an online calculator I found says a 5/16" line 100' long @ 60psi will flow 243 gph/4gpm or at 30psi will flow 117 gph or 1.9 gpm.
We use two separate lines because we put one pump in with around 100 taps, then the second a year later with about 100. and mostly just assumed that we needed separate lines. So we probably could run them both into one, but we also have to take those home run lines down yearly so we just roll both sap lines and the air line up together on a big cable spool. I don't know if we could do that with a bigger single sap line or not.

I dont think with those results you are wasting line. And it feels like I might be getting to the upper limit of what i can push over the hill without a traffic jam at the pump on warm days. This year i will have 125 taps from two pumps trying to get into a single 5/16 line to get home.

Happy boiling!