How much vac is helpful?

[backyardsugarer]

First run with a vac pump today. I am working with lines that have been neglected for years so I knew getting vac would be tough. I got 21 in the tank and let it lose. Before I knew it I was drawing just 4. Started walking the lines and made some fixes (leaks give themselves away now). Got about half done and was up to 9. I will finish tomorrow, but what if I only get to 12 or 14? Is it worth it? It seems to be sucking hard already. I believe I am aiming for 18.

Chris

[royalmaple]

You want all you can get to the taps. There is research on vacuum levels and sap flow. Too tired to spout it off now, but its out there. More vacuum=more sap, plain and simple.

If you can get 21 off your pump without killing it, then shoot to get that at your taps too. If it is a tight system there's not much to say that you can't get that all over if you have enough cfms and properly set up tubing.

[gmcooper]

Chris,
The first year I ran vacuum I ran at 14-15" at the booster and did noticebly better than gravity. Fixing an old system is a slow process. Evertime you make repairs and gain a couple inches vacuum you can go back over and find new leaks at the higher level. Eventually you will get most of them or have a heart attack walking tubing. Proctor maple has a good chart on sap production under various levels of vacuum.
Good luck
Mark

[Russell Lampron]

Most of the time for an old system it is better to drop it all on the ground, roll it up, haul it out of there and start over. I have been doing nothing but repairs on my 400 taps on tubing. I no sooner get it fixed and something else breaks or comes apart. As far as vacuum levels the lower (higher number) the better but 12" is better than no inches and if you can get 18" and maintain it that would be super.

Russ

[TapME]

Russell, did you and Matt do a study on vac in one of threads, I can't recall which one it was in. Where you did the shop vac test. If i remember royalmaple posted the study the governor gave him.

[brookledge]

Chris
Keep working at it. It takes time to keep all the lines and taps from leaking but well worth the added sap. I try to walk all my lines as much as I can. I usually will just walk the mainlines and inspect each lateral line as it comes into the mainline. If you have a leak on a lateral it will show by the sap wizzing by compared to a steady flow.
Another trick I have learned is to walk along and run my hand under the tubing or mainline. If you have a tiny nick in the line it may not be easy to see it leaking but the tubing will be sticky where the nick is so you can make the repair. I usually go walking with a hammer and a roll of electrical tape. Any thing that that won't fix I'll come back with the right supplies.
Keith

[802maple]

Keith pretty much hit it on the nose. The other thing that a lot of sugarmakers overlook is if the tubing can spin on the fitting it is leaking. It doesn't seem like much. A theory I have heard before which is kind of funny but true is, "a single hair is a hair but 400 is a rope". I have been told in the past that a system is tight with no leaks and they went around and check for this problem and gained a couple more inches.

Keep your head high and keep on keeping on.

[Russell Lampron]

Lou,

Matt did the study with the shop vac. I was there to see the results and I was also there when hooked up and old piston type compressor as a vacuum pump.

Russ

[backyardsugarer]

Thanks guys, back at it today. The goal is 15 or bust! Looks like we may get a run as it was 27 this morning before the sun came up.

[Jim Brown]

Gentlemen : What I don't know would fill a library. but i need a little infomation about the surge pumps sp-11 and the old BB models. Any and all info will help. I have a DeLaval 73 that just don't seem to want to pull as much as I want and looking for a replacement.I have it on 400 taps and I'm struggling keeping 13-15 inches, even with a dry line 300 feet up the hill.

Thanks in advance for any help

Jim

[backyardsugarer]

16.5 lbs last night. I must still have a few small leaks but I am making good progress.

Chris

[Brian Ryther]

Last week when the sap was running good for the first time, I was able to maintain 18" consistantly. This week when the sap was barely moving the vac levels were 20" +. The regulator is open all of the way. The pump is a massport m5, so when it gets around the 20" range it begins to smoke and over heat. Is it common for the vac levels to be harder to mantain when there is a good run?

[WESTVIRGINIAMAPLER]

Chris,

You have really expanded the setup????

[802maple]

JB sometimes the pump gets gummed up and it won't operate to its potential, I have put some kerosene thru them sometimes while they are running and cleaned them up, and brought them back to life. The vanes get plugged and sometimes this works. I just trickle about a 1/2 gallon thru the pump, or it could just be time to rebuild as that pump should be more then enough for that many taps. As far a the sp11 goes that is the workhorse of vacuum pumps and also would be just fine for that many taps.

[royalmaple]

That model 73 is easy to take apart and clean out. Really nothing to them. If you haven't tried taking it apart and cleaning the gunk out of the vanes, cylindar, and oil resovoir. You'll be amazed at the crap in the oil res.

I'd do that first before I bought another pump but the piston pumps are pretty much bullet proof.

When you decide to go liquid ring, give me a shout.

[Russell Lampron]

Jim I have a Delaval 73 and if I close off the regulator and the valves at the releaser which is 900 feet away it will pull 25" no problem. If yours won't do that It might have worn or sticky vanes. Mine has a 3/4 hp motor too and is rated at 6 cfm with that motor. If running kerosene through it doesn't free it up it is easy to take the side covers off and disassemble it to clean it out. Be care with the vanes, they don't make them anymore.

Russ

[OGDENS SUGAR BUSH]

i am running a sp11 pulling 20" at the pump 16 " 1200 feet away with 2 / 5 ft ladders and i know i have a couple of small leaks

RICH

[danno]

Brian - when you were pulling 20+, were your lines frozen? Sometimes with frozen lines, vacuum will run higher as you may have frozen sap in your line restricting the vacuum.

If the 73 is anything like the 75, you can clearly hear your vanes clicking. If they are not clicking, or the clicking is random, you need to pull apart the pump and clean out the gunk.

I could not believe the amount of gunk, especially in the oil reservoir and air intake, when I tore mine down. I'd say the air intake was 2/3 restricted.

[sweetwoodmaple]

Yes, the farmers or whoever must have run these pumps without ever checking them.

I just rebuilt a 75 this year and there was barely any room for oil in the reservoir it was so caked.

Also, the side plates were scored .030 deep.

Even with that much wear, you can always grind the side plates, hone the bore and put in new vanes and bearings (one brass, one ball) and you are ready to go.