using 5/16 as a main line

[pprus]

The neighbor is allowing me to tap his property which will add another 90 taps. I know that you should not have more than 30 taps on 3/16. The area being tapped is all up hill from my house/sugar shack. It is also a minimum of 1000' up the hill to that area with about 200' of vertical drop. Could I use 1 line of 5/16 as a mainline and have the 3/16 run into that. I would be using 3/16 going as a lateral from tree to tree with no more than 30 on a line. My other option at this time would be to run 3 lines side by side down the hill to my sugar shack which is 3x as much tubing. Thanks for your insight.

[Mead Maple]

OP, one thing to keep in mind is the amount of sap each line is capable of holding. You’re definitely thinking in the right direction for using 3/16” to tap and collect sap. However, using 5/16” as a mainline will choke down your yield potential due to its size and flow capabilities. This probably isn’t the most accurate when measuring sap line potential, but if you figure (3) 3/16” lines as a whole you get to 9/16” total. Now the folks on here will definitely correct me on what 5/16 is capable of holding for sap flow but I’m pretty sure 90 taps on 5/16” will end up hurting your yield. For 90 taps I think folks are probably going to recommend a minimum of 1/2” but if you plan to use this for several years 3/4” might be the way to go. I’ll let the gurus chime in and more than likely correct me. I saw no one had replied and wanted to give you some food for thought.

[buckeye gold]

I have 4 laterals in 3/16, totaling 100 taps that hook into a 1/2" mainline and it handles them fine. The 1/2" could do more if I needed.

[DrTimPerkins]

... I’m pretty sure 90 taps on 5/16” will end up hurting your yield. For 90 taps I think folks are probably going to recommend a minimum of 1/2” but if you plan to use this for several years 3/4” might be the way to go.

No need to correct you. Historical research suggests that 50 taps on a 5/16" gravity line is maximum. A 1/2" line will probably work, but a 3/4" line has about double the internal cross-sectional area of a 1/2" line. While any of the options suggested (3 3/16" lines, one 5/16" line, one 1/2" line or one 3/4" line) would work, there is less chance during peak sap flows of overloading the line and causing frictional losses and backup with a 3/4" line, leading to reduced sap yield. If the cost difference is minimal, I'd go with that. There is a greater tolerance and far less issues with sagging/freeze issues with 3/4" too.

Just make sure that your 3/16" lateral lines extend at least 30-35" down in elevation below the last tap before entering any sort of mainline to achieve maximum vacuum.

[PCFarms]

The one advantage to using a 5/16th line would be that you can also develop a natural vacuum in 5/16th line when there is high flow. This is not possible in a 1/2 or 3/4 mainline. Last year I tested this with smartrek on a long 5/16 lateral on a hill with some slope - the vacuum at the top of the line increased during high flow conditions. We had 10 taps on the lateral.

If you have 200' vertical elevation change to where you are planning to put in your 5/16 mainline, that could be a huge bonus, plus you wouldn't have the long term clogging issues with 3/16 fittings.
We installed a new bush with 3/16 this year, 700 taps, all natural vacuum. I have a few 5/16th mainlines carrying between 90-110 taps each (3 to 4 x 3/16 laterals coming into each). I have placed a bunch of vacuum gauges on one of the lines, I will collect some data throughout the season to see if there is a problem (ie. measurable decrease in performance due to friction losses). Assuming 0.15 Gal per tap per hour (very heavy sap run), friction losses become significant above 75 taps on a 5/16th. With the current set-up (lots of taps), I want to be able to measure head losses due to friction - assuming I have time :) I have surveyed the elevations of the taps so I can compare calculated vs actual vacuum at the end of the season.

[maple flats]

While it's not impossible to get natural vacuum in 5/16 it would be very rare. The reason, is that in 5/16 the air (gases) can pass the sap, thus hard to generate vacuum in it from gravity.
I'd suggest either of 2 choices, If the slope continues, either extend the 3/16 all the way, or use a 3/4" mainline. The 3/16 will ensure you have max. vacuum on every tap, the 3/4 main line will carry the sap without backing up in the main and reduce your flow.
If calculating your costs, include a saddle fitting for each lateral entering the main, a hook connector and the price of the support wire along with the twist ties and your time to install it. Don't forget to add the cost of an anchor at each end, and likely posts or side ties. Personally I'd favor 3/16 all the way just for the ease of installation and the cost of those extra items.

[pprus]

I am a very small producer, this year going from 135 to 200+ taps. I have looked at 3/4" mainline and it looks like it would be great to use but it seems as though it should be as straight as possible and I am tapping the sides of a ravine in which the ravine is not really straight. The mainline would run right up the ravine with the laterals coming down to it. Most would have well over 30 feet of drop. I am also trying to be as cost effective as possible. It appears that I would need a bunch of new tools and equipment to run a 3/4" mainline.

I will give this idea a try this year and re-evaluate for next year.

PCfarms I would be interested in what you find out using the pressure gauges.

Dr. Perkins, You have me a little confused since you say that

suggests that 50 taps on a 5/16" gravity line is maximum. A 1/2" line will probably work, but a 3/4" line has about double the internal cross-sectional area of a 1/2" line. While any of the options suggested (3 3/16" lines, one 5/16" line, one 1/2" line or one 3/4" line) would work

If 50 taps should be the max number of taps for 5/16 should I be using 2 lines of 5/16 with about 45 taps on each line? Or 55 taps on 5/16 and 35 taps on 3/16?

I really appreciate all the information you guys are providing me. It is a lot to think about with not a lot of time to get it done since I probably should be tapping in about 2 weeks or so. I am in central NY.

[DrTimPerkins]

Dr. Perkins, You have me a little confused since you say that

suggests that 50 taps on a 5/16" gravity line is maximum. A 1/2" line will probably work, but a 3/4" line has about double the internal cross-sectional area of a 1/2" line. While any of the options suggested (3 3/16" lines, one 5/16" line, one 1/2" line or one 3/4" line) would work

If 50 taps should be the max number of taps for 5/16 should I be using 2 lines of 5/16 with about 45 taps on each line? Or 55 taps on 5/16 and 35 taps on 3/16?
.

Any of the options suggested would work, but it comes down to what your goal is.

Do you want the maximum achievable yield (and not greatly concerned about cost or complexity)? Then have the 3/16" lines run into 1/2" or 3/4" mainline.

Don't want to use mainline (due to cost or complexity), but want good yields at a reasonable (slightly higher) cost? Then have all your 3/16" lines run to the tank or transition to 3 lines of 5/16" after a 30' fall from your first tap (going uphill) on the line (this one doesn't make a lot of sense unless you already have 5/16" tubing).

Want to go cheap and don't care about getting the best yield? Either run all 3/16" lines to the bottom or cheapest would be to connect them all to one 5/16" "mainline".

[Mead Maple]

Also ease of installation should be added in. 3/16" is by far the easiest to carry, run, install vs all the others. I won't say that it's the best long term solution but as we all know, running 3/16" is a dream compared to adding solid tubing like 1/2"-1" with wire, ties, and end hooks with tensioners. If it were me I wouldn't bat an eye at the 3/16". I run everything down to a central location and maximize my elevation drop and get the max achievable natural vacuum. 3/16" is cheap, and if your neighbor decides to "pull the tap" on your operation, it's pretty minimal to remove and also looks way less invasive in their woods which can put off some folks who don't see the benefit.

[pprus]

Sounds like I need to order up a bunch of 3/16 tubing so that I have 3 lines of 3/16.

Thank you for all your input.

[DrTimPerkins]

Sounds like I need to order up a bunch of 3/16 tubing so that I have 3 lines of 3/16.

Probably the best approach. It comes down to what your goals and budget are.

Carrying capacity largely comes down to the following....

3/16" tubing (ID) cross-sectional area = 0.028 sq inches
5/16" tubing (ID) cross-sectional area = 0.077 sq inches
1/2" pipe (OD), 0.622" (ID) cross-sectional area = 0.3 sq inches
3/4" pipe (OD), 0.824" (ID) cross-sectional area = 0.53 sq inches

So having three 3/16" tubing lines run into one 5/16" might work, but it might also be maxed out during peak flows. 1/2" or 3/4" pipe would also work. Using three 3/16" runs is also doable and probably about the same cost as 1/2", but easier to install and ensures that you don't have all your eggs in one basket. If there is a leak on one line it won't affect the other two lines.

[Mead Maple]

Sounds like I need to order up a bunch of 3/16 tubing so that I have 3 lines of 3/16.

Thank you for all your input.

:mrgreen: Now we're talking! Good luck and let us know how you do!