cfm loss on mainlines

[PATheron]

Guys- I think I heard that Mr. Childs did a study on cfm loss on mainlines but cannot find it anywhere. I have a spot this year where I have a releaser approx 4000' from my ring pumps. I have two pumps, a ten horse and a three I can run together with a combined rating of 165 cfms or reallife 144 at 25" of vac. I have two one and quarter inch pipes running to the releaser with very few couplings like maybe four or something total. A couple each pipe or maybe three each. With a pretty tight system anyway of figuring out from that how many cfms Ill have over there? Ive probly got taps as far as 2000' from there on a wet dry system thats pretty much by the book. Im not too worried about that part of it I just would like to know if I can figure out the cfms at the releaser to see if I have to put another line to it. Thanks Theron

[PATheron]

I forgot to mention theres 6000 taps total on the pumps. Theron

[GeneralStark]

With 144cfm at the pump at 25", each 1.25" line probably has approximately 10 cfm at the releaser, so about 20 total maybe. This is according to the line loss charts in Mr. Childs workbook, though these only show to 100cfm at the pump so I am sort of guessing. At 100 cfm at the pump, there would be 7 cfm at 4000" with 1.25" pipe. Anyone have line loss charts at higher cfms?

You probably want 60 cfm at the releaser for 6000 taps right? Maybe more pipe is in order?

[PATheron]

General- I wasnt very clear. Theres 4000 taps in other places back at the sugarhouse hooked to those pumps and then roughly 2000 taps on the releaser that the two 1.25s feed so it sounds like its kind of what I expected, itll just barely work if its real tight. Might need another line. Theron

[PATheron]

Other thing I dont understand about how those figures work is there are all sorts of other taps on those same pumps so Im not just giving those two lines a true 144 cfms so Im not sure how you could figure it. I cant afford to run a ten horse pump just for those 2000 taps. I just dont see how you figure anything for sure with multiple bushes on the pumps. The only thing Im really willing to do is either run another pipe over there say an 1.5 inch pipe with them or buy another 5 hp pump for the sugarhouse but thats getting to be a lot of pump. The distances are making it tough on me. More pipe or more pump? Theee(dont want to get cheated out of my bigsap)roon

[spud]

According to the book Steve Childs has out it says that 4000 feet of 1 1/4 pipe will give you 7 Cfms. Although the same amount of Cfms will happen even on a 15 Cfm pump. The chart says that you would still get 7 Cfms at the 4000 foot mark with any pump that creates 15-100 Cfm. So if you are running two 1 1/4 pipes then the most you will get is 14 Cfms. You could add 10 more pumps and you still would only get 14 total Cfms on the size pipe you are using. The only way to increase is more pipe going to the releaser. If you ran one two inch pipe it would give you 23 added Cfms giving you a total of 37 Cfms to the releaser. You will need that much because of the lose of Cfms from that point to the end of your mainlines. Your looking at about $3500.00 in pipe and wire to get the job done.

Spud

[wglenmapler]

Theron,
You should get ahold of Steve and ask him to send you one of the notebooks. It makes great studying for when the lights went out in the headlamp and the wife won't let you take batteries out of something else so you can go back to the woods.

[PATheron]

Spud- That just helped me a lot. Childs is saying no matter what thats all that that run of pipe will let through it. Im going to run another big pipe over there becouse that hill is some of my nicest trees. Last year I had half the taps over there and I was down one inch of vac and I still got tons of sap and that was at only 23" of vac. I just kind of called it good becouse I couldnt afford to do anything different. This year Ill have to run more pipe becouse Ive doubled the taps. Dan- I do need that book becouse of all the far runs I have. It just makes it hard. It still beats feeding a gas vacuum pump everyday though. Weve done that and its a pain. Theron

[Gary R]

Theron,

At that much cost of pipe to run over there, could it be better to install a pump house? You must know someone at the electric company that can set a pole:lol:

[mc-vi]

I dont think you should look out for cfm but more for the vacuum level you can acheive. (it's not the cfm you put in your system that pull out sap from the maple tree but the vacuum level you can acheive at the tree). Indeed, it's also easier to look at the problem in that angle. You can calculate directly the head loss your pipe cause. First, it all depends on your leak. What causes the head loss in your pipe is the friction between the air and the pipe. So without entering to much in details, more you have leaks, more you'r gonna have headloss. Since you have 2000 taps on 2x1.25'' pipe, lets approximate to 1000 taps on 1x1.25'' pipe. If you have a low leak system, your head loss will be very small (about 0.01'' x 250', something like 0.15'' on 4000'). If you have medium leaks it will more look like 0.15'' x 250' so 2.5'' on 4000'. And if you have heavy leaks you are screwed and you gonna have 0.58'' headloss per 250' so something like 9'' on 4000'. Since we know that each inches hg gave us 3-5% more sap you can know if it worth to put another pipe. If your installation are good and you can find most of your leak fast enough, you have enough pipe.
I have a couple sheet frome acer that give headloss for dry maineline (from 3/4'' to 3'') for each 250' (they tested at 20''hg to get a correlation that include the friction coeff. but the headloss should be clause enough at 25''hg). If somebody wants it, just gave me your email and I'll gonna scan them and send them. It's in french, but numbers are universal.

[PATheron]

Appreciate the info guys. Its helping me make a decision knowing some of these numbers. When I started over there I only had 600 taps and could only carry 23". I didnt worry to much and called it good becouse 10% loss on that many taps wasnt real big numbers in money. Now its getting to be more potential loss money. I think there will be 2500 total there when Im done which is pretty substantial to me. Ill have to way out my options but Id say what I have now is going to be negligable. Other thing is Im the only guy in the woods for all my taps with 4 different releasers and three vacuum pumps so between now and season I better have things working just about right. Need to have the releasers heated. Have plumbing so it doesnt freeze etc. Im going to stop hooking up trees end of this week and then Im working now till season making things perfect. Double clamps everywhere on everything. Trees cut that are dead and might come down. Whatever. There is electric at that farmers barn but I hate using thier stuff, etc. Other thing is I use the ring pumps and need cold water near and I dont think there really is there. Have to snoop around. Theron