3/16 tubing... Love it and hate it

[Super Sapper]

My experience with 3/16 on level ground with a surflo pump with around 20 taps and 300 to 400 foot run is a loss of about 1 or 2 inches of vac at the last tap.

[RileySugarbush]

.......Theoretically, a 3/16" line that is 1' long and flat AFTER the slope will generate a resistance of 0.051' H2O of head loss. A 100' 3/16" line that is flat will generate 5.1' H2O (or 4.4" Hg) of head loss. This loss will affect vacuum across the entire length of the line and up the slope. So if your tank was at the bottom of the hill, you'd see negligible loss in your line. If your tank was 100' away across flat land after the bottom of the hill, all the taps on the line would experience a 4.4" Hg reduction in vacuum. Trees at or near the bottom of the hill would experience pressure at the taphole rather than vacuum. ........... Results will also vary depending upon flow rates.

What flow rate are you assuming to come up with that number?

[buckeye gold]

This is what a forum should be....making everybody better. Thanks for all your help Dr. Perkins and I am sure everyone will be waiting to see those articles. I figured my diagram was at least a way to picture a scenario I have. However, after last night's ice storm I will have zero natural vacuum and a whole lot of work on my hands.....I think this is one of those hate it moments. I only walked a short ways into the woods and every line i saw was sagging, on the ground or visibly broken

[markcasper]

I sure wish this information would have come out a few years ago....Man how things changed since yesterday. The good thing is we have some hard numbers to plug into the formula. I have about 150 taps that all run to the east, with major slope from top of hill to bottom. There is a town road all along this east side. Previously, there was 3 points where I had small tanks at the foot of the hill, and adjacent to the town road. The road has a grade to the north of approx. 3-4% and the area of collection north to south is across 40 acres. So, at the furthest point from the south end I was thinking of running up to 2500 feet of 3/16" in the adjacent ditch, the next spot would be about 500 feet from former collection tank, and the last spot the lines would come right from the trees into the tank. I was thinking of using one larger tank to collect from all of these and the idea of running 1000's of feet of 3/16" adjacent to the road and sloping to the north to pickup 30 feet of drop will now be useless, if not counter-productive?

[mol1jb]

First I suppose I should address the title...."love it and hate it." Realistically, 3/16" tubing is a tool. Use it correctly and you'll see the benefit. Stray from the recommendations and you may not like it. That's not a problem with the tool.

Theoretically, a 3/16" line that is 1' long and flat AFTER the slope will generate a resistance of 0.051' H2O of head loss. A 100' 3/16" line that is flat will generate 5.1' H2O (or 4.4" Hg) of head loss. This loss will affect vacuum across the entire length of the line and up the slope. So if your tank was at the bottom of the hill, you'd see negligible loss in your line. If your tank was 100' away across flat land after the bottom of the hill, all the taps on the line would experience a 4.4" Hg reduction in vacuum. Trees at or near the bottom of the hill would experience pressure at the taphole rather than vacuum.

When you have flat land to cross, 3/16" tubing is not the way to go. In those cases, you'd be better off using a mainline from the bottom of the hill, or at least transitioning from 3/16" to 5/16" at the bottom of the hill to reduce the frictional head loss in the tubing (frictional losses in 5/16" tubing are only about 1/10th that in 3/16" tubing at the same flow rate) and trying to ensure there is at least a small amount of slope across the flat area and no sags.

The break-even for minimal slope (where frictional forces = natural gravity forces) seems to be right about 5-6% (based upon engineering calculations). So I'd suggest less than 5% slope, don't consider 3/16" tubing, 5-7% is OK, but probably won't result in huge gains, and > 7% will provide some benefit.

Note that this doesn't include any additional frictional losses due to fittings. That only makes the situation worse. Results will also vary depending upon flow rates.

Dr. Tim

A huge thanks for taking the time to write all that up. This is most helpful for myself and I am sure many others. I like many others are to new 3/16 and this information will help me fine tune my system to be better in future years.

Also I would be very interested in reading your upcoming articles. Could you post the link to where they will be posted?

Thanks again

[Chris_In_Vermont]

We have about 22,000 taps 3\16 hybrid vacuum system and a bunch more than that 5\16. I've put up alot of 3\16 tubing. I like to install it (800' rolls are awesome) and it's awesome the first year it's up. I dislike the maintenance and durability VS 5\16, I think alot of it is due to the early single barb dropline T's (we get alot of pull aparts) But I also prefer checking vacuum on 3\16. Then again, where we have 3\16 is pretty darn steep so I don't like that so much. I don't know, still on the fence about it (hybrid vac system) Leaning towards preferring 5\16 for high vac system. If no vac pump is available and you got slope, there's no question. Like you said, some days, love it and hate it.

[mol1jb]

We have about 22,000 taps 3\16 hybrid vacuum system and a bunch more than that 5\16. I've put up alot of 3\16 tubing. I like to install it (800' rolls are awesome) and it's awesome the first year it's up. I dislike the maintenance and durability VS 5\16, I think alot of it is due to the early single barb dropline T's (we get alot of pull aparts) But I also prefer checking vacuum on 3\16. Then again, where we have 3\16 is pretty darn steep so I don't like that so much. I don't know, still on the fence about it (hybrid vac system) Leaning towards preferring 5\16 for high vac system. If no vac pump is available and you got slope, there's no question. Like you said, some days, love it and hate it.

Thanks for the info Chris. What is your setup like and how many years have you been running 3/16?

[maplefrank]

Get the hottest paper, wear gloves, break I to and rub on the line.... If you don't think it works, stick your tongue o. It.... If you still think it won't work stick you'd toungue on it again! Took a few hours before I could feel tongue! !

[mainebackswoodssyrup]

Thanks for an honest report on the 3/16" tubing Chris in a big time sugar operation. Keep us posted on how it does over the long term.

[Brandy Brook Maple]

Some may laugh about "Wood Chucks" climbing trees but I saw one 6' up a tree this summer.
At first glance I thought it's head was the snout of a Moose.
Get out and enjoy.