Gravity and Slope

[sugarnut]

my main collection barrel sits at the edge of the sugarbush and i have tubing with no vacuum and rely on gravity. the slope next to it is fairly shallow and runs @ 200+ feet at that slope. it's not flat and it does have drop, but the next @150 feet runs at a much better slope. i branch off there and the two legs run in different directions, one shallow like the bottom section and one with more of a slope like the steeper run uphill.

i read on here that steep is not necessarily good...i have no idea really, but i figured it was a plus. i was wondering if any benefit of the steep slope (if there is any) is lost when it flattens back out at the bottom. also, until i get more mainline (next year) the mainline turns in an "S" to hit an area with more trees.

also, the mainline does not continue on very much past my last taps. there is not much pulling on the taps at the bottom.

i was wondering ...

...if i gain no benefit from having no mainline past the last taps

...if the shallow slope at the bottom impedes flow

i'm thinking i need to run wire and have one slope on the bottom two sections, but if i do, the mainline will get pretty high in the "belly" where the two slopes meet.

[Flat47]

I was taught this way: Think of mainlines being like major rivers like the Connecticut (hey...this is a New England story), that runs nearly straight and level. Laterals are like mountain streams - step and fast, twisting and turning.
3% slope is rule of thumb for mainlines. You don't gain any "vacuum" for going steeper because, at a diameter larger than 5/16", there's enough room for the liquid to separate from the gases.
5/16" laterals can be as steep as you want, and will create some vacuum on their own as the liquid falls. But, distance is a factor, too. For gravity I think the rule of thumb is 10 taps per leteral.

Someone chime in here...it's late and I'm fading. Is it 10 per lat?

[sapman]

They say "Strive for 5, no more than 10", and not over 100' in length. And the straighter the better, even on the 5/16ths.

Tim

[TapME]

the NAMPM says that up to 15 on gravity to try and create that natural vacuum, but others on here have put up to 50 on a 5/16 and seems to work well.

[Bucket Head]

I have 44 and 31 taps on two 5/16 lines. They are on a pretty steep grade though. They both run fine and develop some natural vacuum also.

Steve

[Homestead Maple]

Sapman's info is what is recommended by Proctor Research, Leader and Glen Goodrich. Strive for this.

[maple flats]

When one of those high count laterals is running, try pulling one of the lower taps, at or towards the bottom. Sap will shoot out the tap, this means the tap hold is fighting a outside pressure to give sap. This is why the cornell recommended is 5 per line and not more than 10 regardless of vac or not. On good drop high count latterals you do get an impressive stream shooting out but you would have gotten much more sap with the lines having 10 or less taps. What you may gain near the top with a long high count lateral you more than give up near the bottom. These are the paraphrased words of Steve Childs, Cornell maple Specialist and not an exact quote.

[sugarnut]

perhaps it was a bad year, but i once had 10-15 taps on one 5/16 line that did far worse than if i had used buckets. buckets the previous year gave me almost twice as much sap. of course, the bucket year was the first year tapping, so maybe that had something to do with it.

last year was bad for sure. i had 1/2 inch mainline and 5/16 lats with the setup i described above and i feel i should have done much better. the weather was horrible with periods of freezing weather ultimately followed by 65° F temps. i only made @ 4 gallons from @ 60-70 taps. i feel the tubing impared the flow somehow on the good days.

[WESTVIRGINIAMAPLER]

If it's bad, it's just bad. The only thing that would have likely helped you last year would have been vacuum. If your tubing was set up right, they it didn't hurt you. Yes, I don't think tubing can ever run as much as buckets, I have tried it both ways, but the benefits and labor savings of tubing is well worth it but I don't think it would have helped you much if any last year if it was that bad. Most of my trees are scattered all over, thus aprox 1.5 miles of tubing for 500 taps and I never could do that many on buckets. I would be lucky to do 100 buckets as a lot of my trees are on steep hillsides too.

[TapME]

2 years ago we made 4 gallons of syrup on 80 taps, all on buckets. i was a bad year for us were i live. most of the producers around me use vac and there year was down as well. then again 50 miles from me they had a banner year. It's all in the location and the spring time temps. As far as your tubing try what you think will work after all it is your tubing system.

[WESTVIRGINIAMAPLER]

What is comes down to as said before it the weather during the 4 to 6 week sugaring season. I can be the warmest or coldest winter on record and it may have a small effect, but if you don't get the right weather during sugaring season, it don't matter what happened the prior 10.5 months.

[Bucket Head]

I have pulled taps along my runs to see if I had the "backed up from pressure" problem, and I did not. I also did not have sap "shooting" out at the collection point due to too much pressure.

I know the experts suggest fewer taps per line, but everyone's operation and land characteristics are different. The experts would say that this system won't work. Like I said, these lines are on a very steep grade, so they have no choice but to drain without any problems. These are gravity lines, not vacuum. Vacuum would definately need a different system.

I offer this information for anyone who has very hilly terrain and wants to collect sap without buckets as cheaply and as easily as possible.

Stop by this spring and see for yourself!

Steve