New vacuum pump. How much increase in volume of sap can I expect?

[jdandrews]

I just bought a new vacuum pump for this season. We have been using a converted dairy pump for the last few seasons running at 18" vacuum. When I bought the new pump, the guy told me he is running the same pump and is pulling 26-28" of vacuum. I'm starting to wonder if I have enough sap storage with the tanks that I have. So, here is my question. Is there a percentage of increase per inch of vacuum that I should expect?

[Walling's Maple Syrup]

I would say you can expect at least 30% more sap running at 26" of vacuum. That is a conservative amount. I would not be surprised if you got 40% more.
Neil

[BreezyHill]

Yes, The numbers from UVM and Cornell is 5-7% per inch of vacuum above 15".

So From 18" to 26" is 8 times 5% is 40 % and at 7% is 56%. If the new girl will run 28 then its 50 and 70% more.

For your flow at peak you can calculate.2 gallons per tap. At high vac your peak flow will start at a lower temperature thus making the peak flow more hours of the day.

I run recycled dairy pumps and get 28+" and peak flow rate can happen from 9-10 am to about 30-45 minutes before dusk. The big issue I have is when it runs all night long. RO to empty the main collection tank until I quit boiling at 11 pm or later and calculate the current flow rate to know when to set the alarm clock to get up and switch tanks over. If we get the tanks re situated before season the secondary tank will become primary and will have an over flow to the current primary. This way when the new primary is full the RO fires up to concentrate and then fill the evap tank.

Let me know if you need any other figures.

Ben

[jdandrews]

Thank you for the great information! Sounds like I'm going to need a bigger tank in the woods and another tank at the sugar shack!

[JoeJ]

I installed a vacuum pump in 2006. The first year, the vacuum level was only about 17" due to critter damage and installation mistakes in the former gravity tubing system. The second year, the system was up to 20" and then 24" in the third year. Obviously, as I improved the piping and tubing system, the higher the vacuum level. I did not measure the total number of gallons of sap collected for the first couple years, but during the 2006 season with the vacuum system and RO, all the sap was metered.

2005 541 taps 495 taps on gravity line and 46 buckets 8.1 gal sap per tap (approximated, actually made 97.5 gal syrup)
2006 587 taps 540 taps on vacuum lines and 41 buckets 15.6 gal sap per tap 215 gal syrup
2007 16.4 gal of sap per tap
2008 23.35 gal of sap per tap
2009 34.31 gal of sap per tap
2010 28.65 gal of sap per tap Years since 2010 have been around 28 gal of sap per tap (except 2012).

If you look at my numbers and the percentages that Breezy posted, a 40-50%sap increase is pretty likely.

[jason grossman]

Reme




Remember numbers are just that. It is a learning curve to go from 18in to 24 in. Then to run above 24 there are two big factors, can your system handle the increase and it takes a lot of time in the woods to keep it there all season. Things that dont leak at 18 or 24in will leak like crazy as you get to the bottom.i have run high vac for quite a while and it is always a challenge to keep it there til the end, but the increase is well worth it.

[wishlist]

Well I'm going from nada to this! Just finished making a shelf for the releaser to set on in a 330 gallon milk tank. Ran vacuum pump thru the releaser today just to see what the gast 3040 will do. Looks good to me.

[jdandrews]

Our tubing system is not very pretty but it does seam to be tight. So far. I'm sure we will be in the woods a while fixing things with this much more vacuum. It seams like everything with this maple stuff has some kind of learning curve!

Reme




Remember numbers are just that. It is a learning curve to go from 18in to 24 in. Then to run above 24 there are two big factors, can your system handle the increase and it takes a lot of time in the woods to keep it there all season. Things that dont leak at 18 or 24in will leak like crazy as you get to the bottom.i have run high vac for quite a while and it is always a challenge to keep it there til the end, but the increase is well worth it.

[BreezyHill]

I have only been doing sap for 43 years, since I was five, so there are others with more experience than I, but: My dad's motto was fix it once. When I find a fix, tool or piece of equipment that works and does a good job we use it. Last season we found the max seal saddle was the only one that would stand up to the deer rubing on the lines. I can send anybody out to install one of these saddles and with the screw lock on it I know it is tight. I have had helpers and family over tighten pipe clamps so that style wont work here.

A good two handed tubing tool is the best way to bet a good tubing seal.

If you want your mains connections to not leak buy a tubing vise tool. If you make your own and it is off 1 degree you have a spot that will leak down the road as the tubing ages. These are a PITA...didn't leak for 5 years and then suddenly it is. Last season I double clamped three spots that I cut out this summer to figure the issue. This is more important on SS connections due to their sharper edges.

Things will fail easier at 28 than 24, but don't sweat the little things. I can usually walk the bush in 45 minutes to find and fix an issue. When I have more time I look for micro leaks. One son is a HS senior this year and is really a big help now. After school I expect he will spend time learning to find micro leaks and find and fix everyone early on.

You will always have that ice event followed by wind that will drop a branch and break something. Fix it and move on. You will have fun learning all this new stuff in a few months.

[maple flats]

Additionally you need to realize that the increases are compounded. 8" gain at 5% will compound to a 48% increase and 7% gain will compound to a 72% increase. Keep the system leak free and reap the benefits.