Vacuum on Mainline

[Thad Blaisdell]

So here is a unique question for anyone wanting to throw their hat in. I just finished running the tubing onto a 3/4 inch mainline. The line is just shy of 600 feet. This line will end directly into an electric releaser. There is give or take 320 taps on this line. Now I had guessed 250 taps otherwise I would have run a 1 inch pipe. There is decent slope the whole length and changing the pipe at this point is just not going to happen. The one alternative that I do have is that the upper end of the pipe ends roughly 30 feet from my wet/dry line. Does anyone see a problem with just connecting the upper end to the dry line to get the proper vacuum. The pitch down from the dry line to the mainline is fairly significant, It is a good 15 feet lift so I would not be worried about sap running up hill like a sapladder.

Any thoughts?

[maplecrest]

thad your 20 taps over the 'leader' rating for a 3/4 inch line. the only time that will be a problem is if the 3/4 freezes due to vac leak and no dry line.but dry line is up hill.watch that line for leaks early in the season.you will be fine

[PATheron]

Seems wrong but I cant say why it wouldnt work. In theory you would have better vac at the end of the line when you have a heavy flow on the three quarter and if the three quarter froze up it will go back up 15' easy and run down the dry line which would be a plus. At 25" of vac you will be able to pull a column of liquid 25' up. Better remember what you did come leak patrol time. You get a leak on that line your going to have to shut it off of the dry line to see it. Theron

[Amber Gold]

Brad from the tubing seminar recommended 250 taps per 3/4" mainline and 500 on a 1" mainline.

I think you're solution of tapping in from the top will work fine except for heavy flows when the mainline's running near full, but if it's running that good you're relying less on the vac. to get sap to flow.

[Thad Blaisdell]

I think you're solution of tapping in from the top will work fine except for heavy flows when the mainline's running near full, but if it's running that good you're relying less on the vac. to get sap to flow.

If the mainline is running full at the bottom end, then the vacuum from the dry line would help on the upper half, and keep the vacuum up. My vacuum levels last year were at 27.5 (when the leaks were fixed of course). And I would like to keep that level consistant throughout the sugarbush this year.

I just dont see any negative effect from doing this except in order to check for leaks I would have to shut off both valves at the top and the bottom.

[brookledge]

You could always wait and see what you are getting for vac levels on tha t line and if you are losing to much then tie it into your dry line at the end
Keith

[Haynes Forest Products]

OK I read the replys and im having a hard time with the math. 300 taps filling a 3/4" line? a NEAR full 3/4" line running and filling the main line. I wouldnt be worried about vacuum transfer I would be looking for a tanker truck and a full time driver:) I believe that if you had that much sap running down the 3/4" line your doing everything right and I wouldnt change a thing and the vacuum must be working just fine.

[PATheron]

I agree with Haynes. I kind of wonder if pipe size is a little overblown myself. If you look at the stream coming out of the mains into the releaser and then figure all the mains in the bush there cant be much in each mainline. Last year my best running bush was 650 real nice taps on one bank and it dumped into a tote and ran gravity to the road. The continuous stream into the tank by the road was only the size of a pencil. Granted last year was a very poor year here but that bush made quite a bit of sap and thats what was coming off of that many taps. Theron

[maplwrks]

I run 560 taps on a 3/4" line and it only floods a couple of times a year. When Leader rates the pipe for production, they are accounting for good vacuum transfer in the pipe. I think Thad will be fine, although I would T in the dry line at a couple more places if possible. This would give the sap a place to go in the event of a good run and flooded wet line.

[ennismaple]

I'd try it as-is for this year and see how well it functions. If it's overloaded I'd run a dryline about 200' up from the releaser to take the load off the 3/4".

[802maple]

Adding to the top will not be a problem, There are several vacuum setups that have there vacuum coming in from above. The only way that it will lift any sap up to the upper dry line is if it is frozen or plugged less than 30 feet in elevation from the top. If you are worried about that, at the point you are going to tap into the dry line put in a simple pvc booster connecting both your upper dry line and wet line at that point and if the sap comes uphill it will go into the other wet line. All this will do is nuetralize the vacuum in the line and basically your sap will be running gravity like in your wet dry system.

[Thad Blaisdell]

My other solution may be to just add another 1-200 feet of 3/4 at the bottom and tie it into the existing line (making two mainlines) and feeding that one directly to the releaser. The taps start almost immediately from the releaser. I think I will do a wait and see. I am going to put a vacuum gauge at the end of the line and just keep an eye on it.

Thanks to all the input.

[farmall h]

Thad, you must be self sufficient with 8000 taps eh?

[Thad Blaisdell]

Talk to the bank for me...... I borrowed a ton of money (over 250k)last year and then another 40k this year..... so I wouldnt say self sufficient yet.