vacuum ups and down

[tuckermtn]

we just got a laperrier hobby releaser...so far so good...

since this is our first run with a releaser, wonered if what Dave is seeing is normal- the vac gauge on the releaser runs 22-23" Hg when there is nothing flowing in- then once the lower "canister" starts to get some sap in it, the gauage goes down to 15-16"...is this normal?

pump is an sp-11 with 1hp electric-

pulling on 130-140 taps

thanks for any input..

-tuckermtn

[sweetwoodmaple]

Are you still having the problem?

Does the vacuum recover at all, or stay at 15-16?

[powerdub]

When things in the woods are frozen up it tends to mask any leaks you may have. When the sap starts flowing, those leaks are exposed. If your system is tight it may mean you don't have enough pump.

[tuckermtn]

yes- it still seems to be fluxuating...goes from 16-18 when filling then up to 20-21 when closed off...I think the SP-11 is rated for 5 cfm, so hopefully its enough for the 130 taps...Dave was going to go check a few of the top taps with the guage so we'll see if its fluxuating in the bush as well..

[sweetwoodmaple]

Yes, that was my problem last year.

I think 1 cfm per 100 taps is too idealistic. I don't have that kind of time to spend in the woods checking for leaks.

I like my new pump. 17 cfm for 500 taps. that's my kind of ratio.

Of course, the power company will be sending me Christmas Cards for my patronage.

[Parker]

I had an sp-11 on 350 taps last year and It held 22" all season,,,dont think it is the pump.

[powerdub]

When the vacuum drops off as the sap starts to flow it indicates leaks in the system. The pump will work harder when the sap flows but I would check for a lot of little leaks. What kind of spouts are you using and how old are they?

[tuckermtn]

we are using the CDL health spouts with leader sanitary extensions. The original taps are in their third season. I would guess that powerdub is right in that we have a bunch of little leaks...if my pump is (theoretically) oversized, will that compensate for some small leaks? or will the inches of Hg suffer?

thanks- I'll see if dave has some time to walk the lines

[sweetwoodmaple]

The lower you go, the more leaks matter. Going from 15" to 22" makes a big difference.

Also, a pump that is starting to wear out might be the issue too. Once the tolerances open up, it's the leak thing only inside the pump.

Heavy weight oil helps, but makes it a pain to start up unless you keep it heated all the time.

[powerdub]

I am running 75 cfm on 1500 taps and those little leaks will make my system suffer as well. I was running leader and CDL health spouts and everyone of them would leak at the tree just a tiny bit and it cost me 8 to 10"HG. You can tell if the lateral is leaking right at the main where it manifolds in. If you can see the sap moving any faster than a crawl you have a leak. Most of my sap was whipping in so fast it was wiggling the lateral. Besides the lack of vacuum up the hill, any taps above the leak will not run so you lose a lot if it is the first tap leaking.

[danno]

Scott - need an explanation please.

I was checking my lines for leakes this evening and noticed NO sap in the line above some small leakes. Why will the taps NOT run above a leak. I don't understand the science.

Was also having problems finding the leaks. Are they always where you go from fast moving bubbles to no sap? I had that right at a couple drops. Fast sap below the "T" fitting, no sap above it. The "T" looked fine - wonder if the leak was at the tap? Always learning ...

[powerdub]

I am not sure I can explain the science but I know what I have observed in my system anyway. At this point I should add that no two systems behave the even though they appear to be similar. When I was using the leader and CDL style health spout, the ones with the flutes and sealing rings (not putting down the products, they just didn't work for me) almost every one of them leaked where the spout went into the tree. It was a very subtle leak but combine 1500 of them and it turned out to be quite a loss. The thing I noticed with the less severe leaks is that if you bend the drop in the form of a trap the sap will zip right up and over and the same is true of the line below, however, anything above does not move. The more severe leaks will actually cause like a turbulance in the upperside of the tee and you can see the sap just kind of bubbling and moving back and forth not going anywhere. Now if there is a larger leak at the end of the line it has the same affect at the tee on the drop. It will bubble the sap up the drop back toward the tee until you get far enough away from the leak that the pressure from the tree can overcome the turbulance at the tee and you see sap cruising into the main. I hope this is not confusing you because it is hard to explain something I see but don't fully understand. Sap should flow through the lateral in a tight vacuum system at the about the speed as it would in a good gravity system. If it traveling quickly and making the line shake, I believe there is at least one leak. For me, bending the tubing into the form of a trap seems to work the best.

[powerdub]

I would like to see other comments on this. Anyone got input? I call it as I see it but I tend to have blinders on sometimes. Like danno says, always learning.

[danno]

I've got to wait till I get warm enough for another decent run to look closer at those leaks. I always assumed that the worst that could happen due to leaks - is poor vacuum transfer. If it's actually stopping the trees above the leak from running, that's simply not acceptable.

When I was looking at my laterals yesterday, from the main line up the lateral to the leak - you could see the sap bubbling and whizzing down the line. Above the leak to the top of the lateral, I could not tell if there was no sap in the line OR if the sap was flowing along the bottom of the tube with no bubbles. Don't know - hoping for the later.

[maplehound]

Danno, You could very well need to change those T's. I was out the other day checking for leaks and had 2 places where I searched for ever looking for the leak. The sap was wissing down the line on one side of a T an not moving much on the other. I was shore that the leak had to be in the drop but nothing indecated it. So I changed the T's out and that soleved my problem. ON one of them I found that the T's main body had a little hole chewed into it. I couldn't tell that though till after I changed it.

[Russell Lampron]

I have found a couple of T's in my woods that the tree rats chewed. I don't know what they are after. I never use bleach and I always use my tubing tools when installing or making repairs. Spending a day in the woods makes a big difference. Those little leaks and sags really cut down on the sap flow.

Russ

[802maple]

Alot of people reuse fittings and I find it nearly impossible to get them to seal again, not that it can't be done but you have to take your time, the slightest nick and they are history. Also if you have fittings that spin on the fittings it is time to replace them. Other things that I have observed over the years if you tap to close to a old hole "within 2 inches" you can loose vacuum thru that hole or you tap a hollow tree even if you don't go thru it can loose vacuum if you are within 2 inches. Just for that reason I no longer will tap a hollow tree. As Powerdub said it is a tricky science and that is why the high performance sugarmakers are traveling there lines every day. You have to assume that a line that is not leaking today will be tomorrow.

[sweetwoodmaple]

Yes, this whole vacuum thing can be a real treat. I've lost a couple inches as of late, so I have to go walking as well.

I don't know who ever came up with 1 cfm per 100 taps, but that seems too lean. Does anyone out there actually manage to get 20 to 22" of vacuum with that ratio?

Maybe it's the people who make fittings and tubing as you now need an absolutely tight seal or you don't keep up the vacuum levels.

[maplecrest]

as 802 said, it is not the cfms, it is the drill to go out and look for leaks. as i should be looking now instaed of writing this. if you look at where the lats enter the mains and see sap shooting you have a problem with that line. could be a pin hole, bad tap hole, leaky connector or spout connection. yesterday i had bad spout and adapter connections. i cut the spout off, cut the adapter holder off and slid drop tube over the adapter tube sticking out of tree for a tight fit. the problem will be getting out of tree at wash time. solved that problem for now. but you want high vac you need to spend at least an hour a day looking.

[powerdub]

When you go from a gravity system to a vacuum system you will find a whole lot of problems you did not have previously. It may take switching to a different manufacturers product, or a different proceedure. I used to think vacuum covered a lot flaws, but now I know it points them out. It does not overcome the saggy lines and poorly drilled holes, it makes you walk your woods to find them. Yesterday I was not pulling 17"HG. This morning thanks to my biggest helper, I am puling 22"HG. He walked around for me and found about 6 good leaks. The good thing about an oversized vacuum system is that it makes the leaks a little easeir to find. I have to agree with sweetwood though, one cfm per hundred seems a little lean.

[802maple]

Yeah I agree that is pretty much old school 1 cfm per 100. There is nothing like a lot of valves so that you can centralize your leaks in the woods. I typically have a valve on every line at the releaser with a saddle that I can put a vacuum guage just up line of the valve. By turning the valve off and watching the guage you can tell if you have any leaks beyond there, if the guage immediately starts to fall you have leaks or if it holds for a minute there is nothing to severe on that line. It doesn't mean you shouldn't check that line further down the road but it makes it easy to find the big leaks first. I always have a valve at any connection in the mainline with a saddle just , it does save a lot of walking.

[Maple Hill Sugarhouse]

Like has been said

[danno]

Hey Governor -

How about putting that video on youtube.

OK - next question. If you have enough CFM to overcome leaks, are you still losing sap due to leaks?

I run a Delaval 75 on 400-500 taps with a long transfer line, and never seem to lose much vacuum between the pump and end line - and my regualtor is always sucking lots of air. If I cut off the regulator my vacuum shoots up into the mid 20's, but I let air in before I smoke the pump. I only run the pump at 18 or 19". I have not tested the vacuum at the end of the laterals - but I know I'm losing some transfer due to sap in the line.

Anyone looking for a cheap tubing washer - I copied New Hope Mapleman's for about $25. About 2' of 1" black poly pipe with a standard female water hose adapter, air compressor nozzle, pressure guage and check valve all plumbed in.

The air compressor easily moves the water from the garden hose up the 3/4 mile hill into the sugarbush with lots of turbulance to clean tubing and find leaks.

[802maple]

I totally agree with the governor, The only difference between him and I is I like to have 21 to 23 inches to the back of the woods so to accomplish that you have to run a larger pump that won't overheat. He is right that washing under pressure is a way to find blunders. When I had my own bush I used to quick wash the system midway thru the season and you would be surprised what you missed.

[Maple Hill Sugarhouse]

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[powerdub]

From one lame brain to another I will try to explain this in the most simplest terms. The venturi effect has no bearing on what is going on here. The most important element to the venturi effect is missing and that is the orifice. Also, both ends of both lines have to be vented which they are not. Everything above the leaky tee is sealed. We are talking about a pressure differential between the side of the tee that leaks and the side that is not leaking. I will concede one point though, some sap may be getting by but it is slowing things down so that you are losing enough sap to make it worth while to fix the leak. I am willing to agree to disagree on this but due to the condescending tone of the reply I felt I had to defend my position.

[Maple Hill Sugarhouse]

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[Maple Hill Sugarhouse]

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