Vacuum Build Time - Shurflo

[snoskier16]

This is my first season running a Shurflo in my flat woods with ~90 taps on 4 separate 3/16" runs coming into a shared manifold. The lines are filled and sap is running to the tank, but I'm not seeing the high vacuum numbers that others are posting. I'm seeing between 12" on the shortest run down to ~5" on the longest run.

My question is does it take time for the vacuum to build in these systems? Do the trees need to seal up around the taps a bit before max vacuum is achieved or do I need to start tracking down leaks?

The entire system, pump, manifold, lines, & fittings are all brand new.

Thanks!

[VTnewguy]

Start looking for leaks somewhere.

[SmellsLikeSyrupNH]

On Sunday I setup my 1st Shurflo, its on 75 taps. I was having an issue where 2 out of my 3 lines were flowing properly, and the 3rd line the bubbles were moving backwards. Was really frustrating to me, then when I started playing with it all of them stopped moving completely. That was driving me nuts as I wasnt sure how to get rid of the airlock. I tried adding a recirculation line to the manifold and that got everything going in the right direction again. Here is a little video below of it working. I was asked already why I wrapped my lines around the end tree so many times, but they arent kinked and with over 100ft of line, i didnt think 4 spirals would hurt anything. I will tell you, walk the lines and check the taps, look for air bubbles, I found a few small ones. Its all new to me, but im learning. I did not put a pressure gauge on the lines, although I do have some, just didnt install them yet. I plan on it, but just a very busy week. Ive gt over 150 gallons of sap in 2.5 days from the setup.

https://youtu.be/u1ce71PCl4U

[snoskier16]

SmellsLikeSyrupNH, you mentioned something interesting. I did notice at times the bubbles do move backwards, but they will return to normal flow pretty quickly. I'm already running a re circulation line.

One of the runs has to pull uphill for a bit and I can see the sap moving in the right direction so I know the system is working, but getting things dialed in before the main runs hit is the goal. Looks like I'll be walking the lines to see where leaks are coming from.

[SmellsLikeSyrupNH]

Just look closely, I cant really tell if the air bubbles im seeing are from gas or leaks, I cant find any blatant leaks anywhere and even my 1st tap in the line has air bubbles coming down the line, without anything to go by other than my online resources I just have to assume its ok? lol Good luck though, I hope it works out for you. I have 2 more setups to still install, but I set this one up maybe a little early because the temps were so tempting. I'll do the other 2 in the next 2 weeks.

[mol1jb]

For the system you described (3/16 into manifold) there will be almost no build up time for vacuum. I ran a similar system last year. When a line read 15" vac it was fairly tight. When it read 10" I knew I had a small leak. When it read 5" I knew I had multiple leaks or one large leak. Follow your line with the most air bubbles or line that is flowing faster than the others. Those are indicators of leaks.

[Thegreg20]

You need to add a recirculating line from your collection tank back into your manifold with a needle valve to control flow. You'll get 20 to 22 in. Vacuum that way. These pumps need a little kick start to get vacuum. I just redid mine using a shurflo 3/16 line and very little slope or yeah check for leaks. I had a hollow tree that screwed with my vacuum

[snoskier16]

12F36EE5-B010-4F97-BB56-7175EAD604EE.jpg

Thanks everyone for the tips! Looks like I was just a bit too dainty while putting in a couple of taps. Vacuum is up on all four lines and sap is flowing great right now!

[maple flats]

The real issue may be 2 or more causes. First, on flat land you will get less flow because of line friction. I do it on some lines but I have 26-27" vacuum from a vacuum pump, but while I get decent sap I get less than I would if I used 5/16 and some sap ladders. Second, a shurflo pump does not handle leaks well at all. You must find and eliminate all leaks.
You say you see bubbles coming out of the tap or in the drop line. If they are a slug of air, then one of sap and then air, moving slowly, that is proper. However, if you see small bubbles in the line, you have a leak.
Leaks can come from drilling a hole out of round, setting the tap tight enough to crack the bark or even a bad spot in the tree. When you drill, go in without any wobble to the drill. It is best to use a genuine tapping bit, but if very careful and with a common hardware store drill bit it can be done. The bit MUST be sharp, drill in 1.5-2" at a slight upward angle in one motion. Keep the drill motor running thru the entire process, do not stop and start it and do not drill back in. Do not blow into the hole to get shavings out, if you need to break a small stick from a nearby tree or bush, to clean out the shavings, then throw it out, if you need to do another hole, get a new twig, and do not touch the end that will be stuck into the hole. Several times a leak is from drilling in and out 2 or more times, or from "hammering" the tap in too hard. I do not use a hammer, but rather the flat jaw of a 7" pair of lineman's pliers. Any help I get also use the same. If you want to use a hammer, get a tapping hammer or a mini hammer, like a 7 or 8 oz one, then tap lightly, just until the sound changes. If you do invest in an official tapping bit, do not use it for any other hole drilling.
Once you get all leaks fixed the sap will run towards the pump. As others have said, a re-cycling loop helps on a diaphragm pump. To do that, you can simply run a 3/16 line from the pump outlet back to the manifold. That keeps the diaphragm wet which greatly helps performance.
You need to realize that a shurflo will not keep up with any but the tiniest of leaks, but when you get it running as best it is capable it will help a lot.

[SmellsLikeSyrupNH]

Great post Dave