Vacuum system for small runs (200 taps or less)

[Dale Sparrow]

I have three runs of 60 taps and one with 110 all on 5/16 with good slope. None of the runs can be hooked together do to terrain and distance. I have decided to build four separate vacuum systems to get everything on vacuum, I am able to run 115v power to all locations. These are the parts I will be using to build my vacuum system, one stainless vacuum tank (from Hamby dairy supply), one Northstar 4gpm 12v water pump (I like this pump because it is rated continuous duty and can self prime from 12ft), one 115v to 12v converter (to run water pump), one 3cfm 115v rotary vane vacuum pump, one marine type float switch, one duel action relay switch, two check valves and two ball valves. Cost will be a little over $400. Plan is to mount float switch inside vacuum tank and connect to relay so that when float switch goes up it will turn vacuum pump off and turn water pump on, when float switch goes down will turn water pump off and turn vacuum pump on. I am thinking system should pull 20-25 inches of vacuum when water pump is running and between 25-30 inches when vacuum pump is running. Any thoughts?

[psparr]

How old is the tubing? If you have the slope you can switch out to 3/16 tubing and get near 30" of vac for free. Granted the cost of tubing, but no need for multiple vacuum pumps and electric bills.

[Dale Sparrow]

Tubing is new. Slope is good but not much distance Top of hill to bottom only 200 feet with about a twenty foot drop.

[jmayerl]

So if I understand you correctly, this is only with 5/16 tubing(no mainline) if so, vacuum will not work as the line are already over tapped and vacuum will not transfer. If I am not understanding correctly them tell us more about your runs.

[Dale Sparrow]

Got the tubing for free so will see how it works. I think vacuum will transfer with such a short run. I read that people are putting 30 plus taps on 3/16 and 5/16 is nearly three times as big as 3/16. I said I had a run with 110 taps but I should have said two runs with 55 each that meet at the bottom of the hill but will run to the same vacuum. If I find that there is considerable vacuum drop at the top of the hill next year I will add some larger main line or maybe run a dry line to top of hill as I got six 500' rolls of 5/16 for free.

[markcasper]

Got the tubing for free so will see how it works. I think vacuum will transfer with such a short run. I read that people are putting 30 plus taps on 3/16 and 5/16 is nearly three times as big as 3/16. I said I had a run with 110 taps but I should have said two runs with 55 each that meet at the bottom of the hill but will run to the same vacuum. If I find that there is considerable vacuum drop at the top of the hill next year I will add some larger main line or maybe run a dry line to top of hill as I got six 500' rolls of 5/16 for free.

I'm thinking maybe your not understanding that 5/16 will not work with natural vacuun like 3/16 because of the diameter. As other have said, you won't get vacuum transfer with that many taps on a 5/16. yes 5/16 is 3 times as big, but the concept doesn't mean you can put 3 times as many taps on and get the same results.

[Dale Sparrow]

From what I have read 3/16 needs at least a 150' going down hill after last tap to achieve a good vacuum. to achieve same results with 5/16 the run after last tap would have to be 450' down hill (by down hill I mean a grade of at least 10 degrees). I am not trying to set up a natural vacuum, I don't have the room. My runs are less than 200' a 1/4 of the trees are at the top, 1/2 are on the hill, a 1/4 are at the bottom and grades are 10 percent or greater. I think this will work good with a vacuum system. Worst case scenario I will need to run a dry line to top of hill or put in a 1/2 - 3/4" main line or both, shall see, either way I will still need a vacuum pump to achieve a good vacuum.

[jmayerl]

3/16 needs 32' of drop for maximum natural vac.

Not sure where your info is coming from but it sounds a bit skew.

Vacuum will not transfer with that many taps. Ideally 3-5 taps per 5/16 line

[mainebackswoodssyrup]

I've found in the woods we help with, 5/16" runs over 150' and/or with more than 8 taps have little or no vacuum at the end tap. It is a sharp drop off. And its an oversized pump so that's not the issue. Had good vacuum all season on the gauges but we really noticed the difference in some of the lines while cleaning and pulling taps this weekend. I am sure there is a science behind it but I'm fairly new to vacuum and have lots to learn.
Set up a mainline and use your free tubing for laterals. Fortunately for us it is only a few hundred taps out of the 5400 to fix. Don't shoot yourself in the foot before you get started. There is a link on here somewhere to a Cornell report about vacuum. Take a few minutes and read it.

[GeneralStark]

I have three runs of 60 taps and one with 110 all on 5/16 with good slope. None of the runs can be hooked together do to terrain and distance. I have decided to build four separate vacuum systems to get everything on vacuum, I am able to run 115v power to all locations. These are the parts I will be using to build my vacuum system, one stainless vacuum tank (from Hamby dairy supply), one Northstar 4gpm 12v water pump (I like this pump because it is rated continuous duty and can self prime from 12ft), one 115v to 12v converter (to run water pump), one 3cfm 115v rotary vane vacuum pump, one marine type float switch, one duel action relay switch, two check valves and two ball valves. Cost will be a little over $400. Plan is to mount float switch inside vacuum tank and connect to relay so that when float switch goes up it will turn vacuum pump off and turn water pump on, when float switch goes down will turn water pump off and turn vacuum pump on. I am thinking system should pull 20-25 inches of vacuum when water pump is running and between 25-30 inches when vacuum pump is running. Any thoughts?

I hate to be a Debbie Downer but there is no way your releaser will work as you are describing it. I assume you are thinking that the pump will be outside the releaser chamber and pump the sap out, and if that is the case a pump with a 12ft head capacity will not pump out of a vacuum chamber unless the vac level is about 10" and even then it would be questionable if a diaphragm pump could do it. Also, even if it were capable the on/off scenario you describe would likely destroy the motor pretty quickly. You would be better off just hooking the pump direct to the 5/16 lines.

What others are trying to say about your 5/16 mainlines is that the line loss from friction will be too great to effectively achieve much vacuum at the tap. Vacuum is a lack of air and you are attempting to remove air and sap from the line and they compete. The air moves faster but will be limited due to the sap in the line. Because of the small ID of the tubing, air will not be effectively removed and thus the vac. level will be low at the tap. This is why producers using vac. effectively use more mainline (larger diameter) and less tubing (small diameter) and keep the laterals short with few taps on each lateral.

[Dale Sparrow]

Head capacity is how far a pump can push a fluid up, prime capacity is how far a pump can pull a fluid from. From what I have read it takes aprox. 1.3" of vacuum to pull water up one foot (I got that from a fireman's book.) According to that a pump that can self prime from 12' above said fluid is capable of creating 15.6" of vacuum running dry. I am betting it will easily pull in the twenties running wet.

[Cedar Eater]

From what I have read 3/16 needs at least a 150' going down hill after last tap to achieve a good vacuum.

You're misinformed. Even with some small leaks in the system, maximum vacuum can be achieved with less than 50' of height above the low end of the tubing. And that's maximum vacuum for any tree above the 50'. Lower trees will still get some vacuum. Make a hybrid system with both natural vacuum and mechanical and you can get maximum throughout the sapline.

[Dale Sparrow]

Hybrid is what I am shooting for. From top to bottom is about a 25' difference in elevation. I have read other people's posts that have a nearly identical layout as mine and are getting 8-9" of natural vac at the top of the hill running just gravity, all 5/16 line.

[GeneralStark]

Well it seems like you already have all the answers so good luck with your project.

[Dale Sparrow]

After sleeping on it I think you are correct that water pump will not pull against a vacuum that is above what the water pump can pull. Will have to install an active ball valve with a relief valve allowing vacuum to drop to a level acceptable for water pump to work. Ordered a tank and water pump yesterday, already have a vacuum pump and float switch. Can't wait to experiment a little.

[mainebackswoodssyrup]

The thread with links to UVM research and Cornell's publication:

http://mapletrader.com/community/showthread.php?26571-Understanding-vacuum-systems&highlight=cornell+vacuum

[Wanabe1972]

I have a couple of seasonal lines that i run 35 to 45 taps all on 5/16. I use aquatech 5800 pumps. They pull 15 to 18 inches of vacuum all day and can run dry. I know this is not ideal but without the pumps these lines ran .5 gpt on average and with the pumps I can see 1 plus gpt on average. They are a mix of reds and sugers. I just bought the 110 volt versions so no converter was needed and the pumps could be run for other purposes. Jeff