1000' 5/16 lateral?

[bmbmkr]

I'd like to get some of your opinions on these two scenarios.

I plan to run a 5/16 1000' "mini mainline" that will be fed by 30 taps on two 3/16 laterals. A 400' with 14 taps-100' drop and a 600' with 16 taps 140' drop, The 1000' of 5/16 will drop 150' to the bulk tank, and have a shurflo pulling it.
Is any one else running 5/16 this far? Will I even need the pump?

I am going to cross 200' of a hillside field with 5/16. I think I can stretch it between t-posts spaced 20 ft, stretch it with hollow core nylon rope. I'm wondering if I should I put the posts in a straight line, or zig zag them so i can side tie the lateral to keep 3' or 4' pf drop per hundred. The rest will run through the woods, plenty of trees to side tie to.

Thanks in advance!

[maple maniac65]

I think sap is going great to sit in the 5/16 line and bottle move. Even with some sort of vacuum

[maple flats]

5/16 does not act like 3/16 in how sap moves in it. With 3/16 the sap and the air (gases) remain separate and move without the gases passing the sap. In 5/16 sap will set in low spots ans the gasses will pass the sap. Also, even with vacuum on it, the flow could "lock up" or stop moving. At that point the only thing going for you will be the fact that the 3/16 will eventually push the whole thing thru, but you will loose lots of efficiency. You will be better off running the 3/16 lines all the way to the pump and join then at a manifold as they get to the pump.

[bmbmkr]

Thank you for the information.

[Chris_In_Vermont]

I would run both 3\16 lines all the way to your tank. Run them right together, wire tie them together if you want. Saves oddball fittings and another tubing size, 3\16 is cheaper too (get 800' rolls) Plus you said another 150' of drop. I'd just zig zag between trees and maintain your tubing tension.

[maple flats]

Another benefit in 3/16 is that as long as you have enough drop, especially near the bottom of the line, little dips in the line are not an issue. I first observed that my 1st year on 3/16. I had a line about 300' long, fairly level near the top of the hill, with a few dips in the terrain. One day I saw a limb had fallen on the line pulling it down about 8-10' in a low spot between 2 tapped trees. As I walked towards it I saw the sap "marching" (sap spaced with bubbles of CO 2) going down under the limb and then climbing back up 8-9' to the next tap. The line still had about 150' distance, 7-8 taps and about 30' elevation drop before tying into a mainline branch. I also have 18-19" vacuum on the system by mechanical pump/vacuum tank.
The limb was too heavy to move by hand and I left it until the next day when I had a chainsaw with me to remove the limb.

[bmbmkr]

I would run both 3\16 lines all the way to your tank. Run them right together, wire tie them together if you want. Saves oddball fittings and another tubing size, 3\16 is cheaper too (get 800' rolls) Plus you said another 150' of drop. I'd just zig zag between trees and maintain your tubing tension.

When I decided to get into this adventure 6 years ago, I bought 4000' of 5/16 to get started. Last year when I finally got to tap and boil, I put in 3/16. I am tripling taps this year, from 100 to 300, all on 3/16 ( a few bags), So I have an extra couple rolls of 5/16 that I thought about trying to use it for something, I already have reducers, no big deal for that, but I don't want to use the 5/16 if it's goin to sag and hold sap. There's not going to be quite enough sap to run another 3/4 on wire for 40 taps. Plus it's across the pasture field, no trees to zig zag around, and I want to be able to take it down in the Spring. If worse comes to worse I can put a tank at the bottom of the 3/16 drive the tractor to it, I just don't want to rut up the fields.

[maple flats]

I have used both 3/16 and 5/16 for the drops, I seem to lean towards the 5/16 for my drops unless I want the option to drill below the lateral, then they should be 3/16. In time you can easily use up 4000' of 5/16 for drops. I make my drops 36" long, at that you will get just 1333 drops, you will then find it easier to change the drops often enough.

[bmbmkr]

I have used both 3/16 and 5/16 for the drops, I seem to lean towards the 5/16 for my drops unless I want the option to drill below the lateral, then they should be 3/16. In time you can easily use up 4000' of 5/16 for drops. I make my drops 36" long, at that you will get just 1333 drops, you will then find it easier to change the drops often enough.

Good point Dave, that'd do me for a few years! I have been reading this year about 5/16 drops on 3/16 laterals. Have you noticed a difference in production? What are the pros and cons? Is there any vacuum loss?

I did some quick math and found that the volume of a 36" 3/16 drop is about 1 cubic inch, and a 36" 5/16" is 11 cubic inches. Does this extra volume affect the vacuum once the sap fills the 3/16 lateral and starts pulling?

[maple flats]

Whatever it may reduce the vacuum is minimal, and the system will not be affected if you have the prescribed drop on the lateral lines. Besides, I don't know what taps you are using, but every company makes 5/16 taps but the selection of 3/16 taps is poor at best, however that improves each year as more companies add 3/16 taps to their product line. I haven't done the math, but those numbers sound high to me. I'll check them later to verify or correct.

[maple flats]

Using my pipe volume calculator, 36" of 3/16 if full holds .035 cubic inches while the same length of 5/16 holds 2.7623 cubic inches. I used a pipe calculator program, but the formula for volume of a round pipe is Pi R squared x height. All numbers must be in the same units.
That being said, the volume held in this case makes no difference. But if you have a 3/16 drop with sap flowing it is usually going to average about 1/2 the mathematical volume because it will have a column of sap/gases/sap/gases. The % of sap will vary depending on the sap flow and the actual vacuum on the drop line, the greater the vacuum the more the gases expand or get stretched out. This only happens in 3/16. In 5/16 the sap slips down under the gases.