3/16 tubing into a main line, can it be done?

[ethanssapshack]

Only put up 20 taps with 3/16 this year, running them into a barrel an was very impressed. I am thinking about changing my 5/16 gravity tubing to 3/16, but have not heard or read anything about running it into a main line. Can it be done? My 5/16 tubing is 180 taps divided into 3 mainlines all gravity feed into two plastic tanks I would like to just change my side lines to the 3/16 in hope it will produce more sap.

please leave any an all advice!

[StayinLowTech]

Sure it can be done. Hopefully you have a good slope for the laterals (3/16" laterals can take 30 taps each) and some distance between the closest tap to the mainline and the mainline itself. Once the 3/16 reaches the mainline, all vacuum is lost. You need a reducer and a small piece of 5/16 to connect the 3/16 tubing to the saddle on the mainline.

[n8hutch]

Pretty sure D&G makes saddles for the main line connection with 3/16 barbs. I was looking at them this weekend. I am thinking about doing just what you described , you just want to make sure you have roughly 30ft of drop after the last tap before you tie into the mainline

[Loch Muller]

Yup, I have 80 taps setup like that into a mainline that also has 60 5/16 gravity taps into it. For the 3/16 I dropped 30 feet after the last tap and switched to 5/16 for the last couple feet before it entered the mainline saddle. I'm going to add another 30-50 3/16 taps to this line for next season.

[ethanssapshack]

I'd like to know with the 3/16 tubing why you need to have a 20-30 foot before entering the tank or in this case it would be the main line? i know it has to do with the vacuum but with my set up this year i had ten taps going into a barrel and it produced really well and they both weren't long lines and did not have only maybe a few feet from the last tap to the barrel. with the main line set up it would be close to the same thing running the taps to the main line with out 20-30 feet before hand.

with the vacuum being lost when it enters the main line will that effect the vacuum being produced?

[maple flats]

In order to have the high vacuum at the lowest tap, you need the drop after that tap. If you run a long run with good drop and the tap a tree at the mainline elevation, you actually are putting pressure on that lowest tap. If you have taps you must get you are better off running the 3/16 for taps that are about 30' or more higher than the main, (25' still works pretty well), and then run 5/16 on the lower ones on a separate line going to the mainline..

[WESTVIRGINIAMAPLER]

In order to have the high vacuum at the lowest tap, you need the drop after that tap. If you run a long run with good drop and the tap a tree at the mainline elevation, you actually are putting pressure on that lowest tap. If you have taps you must get you are better off running the 3/16 for taps that are about 30' or more higher than the main, (25' still works pretty well), and then run 5/16 on the lower ones on a separate line going to the mainline..

I ran mine from top to bottom. Many have 100' in elevation drop and some of the ones near the mainline may only have 2 to 3 feet of drop. I would have to disagree with Dave on this one as one of the worst weather years I have seen here and 400+ on 3/16 produced over 20gpt and lot of them had only few feet of drop while 570 on gravity only produced 4 gpt. Put everyone on 3/16 down to the mainline.

[davrhods]

ran 7- 500 ' runs of 3/16 into 5/16 tubing for 1500' to shack and it ran nuckin futs all season. no specific numbers but was best running system ever in my redneck woods.average 25 taps per line. still owe some coyote abit of lead poisoning for chewing up line # 8.

[WESTVIRGINIAMAPLER]

Don't need to special order any 3/16 saddles from D&G. You have to use a hook connector to hook 3/16 to mainline wire and use the 3/16 to 5/16 hook adapters which CDL sells and prob D&G and use standard saddles. Way I have all mine set up and they work great with aprox 12" piece of 5/16 loop after adapter going into mainline.

[tuolumne]

We have a number of 3/16 lines coming into a 3/4" mainline. We use a 3/16"x5/16" hook splice sold by CDL and use 5/16" tubing for the loop to an ordinary saddle. Since we have no wire on our mainline the hook splice grabs a piece of "rapi-fix" strapping on the mainline. We also have one 3/16" line that drops vertically to the mainline and is fastened higher up. This one has the 3/16" tubing inserted into the 5/16" tubing since there is no load on the connection. This is clean and cheap, and we observed no leaking at all with this 1" overlap connection. In the future, we plan to try a similar connection for lines coming in under tension by using hollow braid rope to pick up the 3/16" load like a Chinese finger. I would still make a loop to the opposite side of the mainline with 5/16 since we all enjoy watching the sap go around it!

[WESTVIRGINIAMAPLER]

Also use a "Y" fork if bringing it in at a tree, it is another fitting but they work great as I used them for years on 5/16.


We have a number of 3/16 lines coming into a 3/4" mainline. We use a 3/16"x5/16" hook splice sold by CDL and use 5/16" tubing for the loop to an ordinary saddle. Since we have no wire on our mainline the hook splice grabs a piece of "rapi-fix" strapping on the mainline. We also have one 3/16" line that drops vertically to the mainline and is fastened higher up. This one has the 3/16" tubing inserted into the 5/16" tubing since there is no load on the connection. This is clean and cheap, and we observed no leaking at all with this 1" overlap connection. In the future, we plan to try a similar connection for lines coming in under tension by using hollow braid rope to pick up the 3/16" load like a Chinese finger. I would still make a loop to the opposite side of the mainline with 5/16 since we all enjoy watching the sap go around it!

[ethanssapshack]

id love to see some pictures of how you have it connected to the mainline.

[psparr]

https://vimeo.com/125885096 Here's my redneck way.

[GeneralStark]

Has anyone been experimenting with long runs of 3/16 connected to a mainline on high vac.? Will it work?

[DrTimPerkins]

Has anyone been experimenting with long runs of 3/16 connected to a mainline on high vac.? Will it work?

Sure. Why wouldn't it? As long as you have a decent slope to achieve the drop to generate the natural vacuum in the 3/16" tubing. The effect would be additive (pumped vacuum in mainline + natural vacuum in 3/16" tubing = total system vacuum), up to the point where you max out the vacuum (at which point the system implodes and a black hole is created in your sugarbush and the earth and solar system are destroyed). OK....that last bit in parentheses is somewhat exaggerated. :lol:

[ryebrye]

Has anyone been experimenting with long runs of 3/16 connected to a mainline on high vac.? Will it work?

I have been playing with this in my area in Hinesburg. It works great. Obviously the sap isn't running anymore, but my tubing is still up - I'm near CVU if you are ever in the area and want to take a look at it I'd be happy to show you what I did and how I did it. To get a setup that works I followed pretty closely the advice that Tim Wilmot gave at the maple school in Hyde Park in terms of which fittings to get from CDL and which ones to get from D&G.

It works great. I have enough slope that I don't really need a pump for 80% of my taps to get over 28" of vacuum - but for some of the lower ones without much drop having a pump helps a lot. I have a small continuous duty gast piston pump that does 4cfm at 27.5-28" on the mainline and was over 29" at the top of all my lines all season long. 40+ feet of drop to my higher taps into a mainline under 27.5" of vacuum and I did have to worry about the black hole effect that Dr Perkins talked about because I was maxing out the vacuum.

When the power went out, my sap still ran like crazy because the 3/16 natural vacuum doesn't shut off. Sure, some of my taps without the steep drop didn't have as much vacuum anymore, but most of them were still in high gear.

[GeneralStark]

This is very interesting. I figured the effect between the natural vac. and pumped vac. would be additive, but I was talking to someone at CDL this weekend about this concept and they were concerned about the 3/16" lines becoming "overloaded" with sap due to the smaller volume. I don't see how this would be an issue, but everything I have read has been about 3/16" without a pump.

I'm interested in exploring this concept as I may have the opportunity to add some taps on two parcels, one adjacent to my land and one adjacent to my neighbors (where I have a lease and have tubing up). Both areas have good slope and in some areas it is quite steep. In both situations I would have to take the tubing down in the off season. To get to both areas I would have to add some more dry and wet line, but then could easily extend a 1" main from the property boundary in to the areas mentioned with the mainline line going generally along contour but sloped at 1-2% into my wet/dry lines. I could then run the 3/16 laterals down slope 2-300 ft. into the mainline. In one area I would probably be looking at 10 taps max per lateral, but in another where there are lots of nice maples, it might be closer to 20-25 taps max/lateral.

Is there a recommended max. number of taps per 3/16 lateral?

[Super Sapper]

I think they recommend 25 taps on a line for natural vac so that it will not be overloaded. If running into a mainline under vac it would be less of a concern with this many taps. I had 3 lines with 24 to 29 taps each going into 3/4 inch lines with shurflo pumps with other taps on and the 3/16 never wanted to stop flowing. The only concern I can see on a system like this would be overwhelming your main line as there should be any negatives for the 3/16.

[DrTimPerkins]

Advice from Tim Wilmot -- When using 3/16" laterals into a mainline that has only low or moderate slope, it sometimes helps to keep the end of the mainline open (and higher up) to allow the sap to run through quickly and freely. Obviously this isn't something you want to do in a hybrid (pumped+3/16" vacuum) system.

[WESTVIRGINIAMAPLER]

Dr Perkins,

Wouldn't this introduce a lot of bacteria into the mainline and cause it to become very cruddy??

[DrTimPerkins]

Wouldn't this introduce a lot of bacteria into the mainline and cause it to become very cruddy??

Yes, but it will get cruddy whether you leave it (the mainline end) open or closed. The difference in recommendation between mainline (leaving the end open) and lateral line (not venting) is that mainlines have only a very very small influence on sanitation in the taphole, whereas lateral lines have a larger effect. If you have enough slope on your mainline, you needn't leave the end open. It will drain regardless. In terms of leaving mainlines open....they need not be completely open, just crack open the valve at the end a little bit to allow a small amount of air in the system.

[WESTVIRGINIAMAPLER]

You guys that are using Chinese fingers are you heating both ends of the 1/4 hollow core rope before inserting tubing in it?

[psparr]

I didn't fuse the ends. Isn't fraying yet. I make it pretty long so it stays.

[WESTVIRGINIAMAPLER]

Anyone using the 600' rolls from Harbor Freight of 1/4 hollow core rope?

[Super Sapper]

Looking online it does not look like it is hollow core rope. It should say in the description and there are several places online when I just checked that seem reasonable.