long term planning and sap ladders

[TRAILGUY]

I know some say only use sap ladders as a last choice, others say they work fine. Some say add a touch of air others say that silly you only lose vacuum when you add air.

So who has done:
1. Used sap ladder and feel it is the right answer for their set up.
2.Used sap ladder and feel it was the wrong answer for their set up and removed it.
3.Would never use a sap ladder even if that was the only cost affective way to have vacuum and stayed with gravity instead.

What is the most rise anyone has on one main and how many steps?

My sugar bush slope away from everything so sap ladder would save alot if they work.

[ennismaple]

The sap ladders we have are to pick up taps we wouldn't get any other way. You do get less sap per tap with a sap ladder. I'd love to have none but with the lay of our land there's no way we can avoid them unless we ignore all those beautiful maples located below the mainline!

[BreezyHill]

Sap ladders work exceptionally well for our operation. There are a few facts/ rules of physics that you must know and utilize in your designing of ladders.
Steve Childs data on cfm over distance of main line is a must read. This explains how cfm is limited by length of mainline...no matter how big the pump is.

This article also gives valuable info on slope and its affects on gpm capacity of mainline, also gpm for tap at high flow runs.

1 gallon equals 231cu inches or .134 cu feet...you cant lift more sap than the cfms of the mainline at a distance...sizing the mainline is most critical.

leakers( needle valve) installed on a y on the last tap of a lateral at the end of the main that has 1 or more ladders is your profit maker.
All you need to do is to allow a minute amount of air into the line to help elevate the sap in the ladder more rapidly than with out air.
This past season I was able to produce 22" on a 218' long 5/16 lateral with around 50 taps with a leaker, on a ladder with a .47gpt yield average.

I used 28 ga needles for a few days and they let in to much air and were not adjustable to zero...so I tried the needle valves and success!
One experiment was adding a check valve tap onto the needle valve to stop sap loss when mains froze...failure...the check allowed sap to drip on the ground.

I would only use a ladder as a management tool.
Only where you need them.
Only for trees that are below grade or where you need to raise the mainline to get a 2% slope.
Vacuum Boosters is a misnomer. Only a vacuum pump will boost vacuum.
VBs are useful to connect mains to large mains when using a wet/dry system...they smooth out surges of sap and transfer vacuum better on a consistent sap flow. They are also cheap for a DIY project with pvc pipe, reducers, and tees.
I prefer to drill and tap a 3" pvc and attach fittings for the dry line main and mains entering ends capped with reducer with 90 degree elbow and y off of dry to top reducers...cheaper that way and less leak potential.

Management 101...watch and learn. Ladders that are left unmanaged will fail. Check them when you can...just like check for leaks...adjust the needle to get the highest vacuum reading possible. Note all adjustment...when you get a good reading, note that; but don't settle for that...play some more.

Drop me an email if you don't have Steves paper and feel free to ask questions.

Ben

[TRAILGUY]

so with more then one ladder is it possible to rise over the out put of the pump? ex. 3 /10 ' ladders for a total of 30 feet with a 20 cmf pump. Has anyone done it?

[mapleack]

Yes you could do 3 10 ft ladders, lift isnt directly related to cfm of the pump, it's related to vacuum level of the pump. The key is having enough gas in the lines to lift the sap. Bubbles moving up move the sap. You either have to have enough tree gas, existing leaks or a purpose made leak to lift the sap. This is where cfm of the pump comes into play, you need enough cfm to overcome the gas volume in the system, be it tree gas, or leaks. If your tubing system is perfectly tight with no leaks on a slow day / low tree gas day you'll see the bottom of the sap ladder filling up with sap and just sitting there for awhile until enough gas builds up to lift. Vacuum cannot transfer through a liquid, so while the ladder sits there full vacuum levels will be dropping beyond the ladder. If you do as breezyhill said and as I also do, and use a needle valve to always keep the ladder moving you'll have constant, higher vacuum levels beyond the ladder. If you have three ladders in series you should only need one needle valve beyond the farthest ladder, it will provide air for all three. I put needle valves on their own mainline saddles so as to not compromise a lateral line. This leak or no leak debate comes up time and again, when it should be basic foundational knowledge that you've gotta have gas there to lift the liquid. Sorry if that offends anyone, but it's physics. I've described my scenario on here before but here's the quick version of my observations. One of my ladders is 12' with approx 40 taps. The releaser is only 50 ft from it, with a vac gauge on it. I installed a vac gauge 30 ft beyond the ladder also. I installed a needle valve on a saddle within a few feet of the gauge beyond the ladder. I was running approx 20" vacuum at the pump and releaser. With the needle valve closed the bottom star fitting of the ladder and several feet of the mainline would backup with sap, the vac level beyond the ladder would drop to 12", then enough gas would build to lift the sap and the level would climb back to 18" to 20". Next I opened the needle valve just enough to keep bubbles going up the ladder at a constant rate. The gauge stayed at 18". Which would you rather have? Steady 18" or fluctuating down to 12"? I'll take my tiny leak and steady 18" plus.

[Maplewalnut]

Anyone have a picture of this needle valve set up? I introduce a small leak at the ladder itself via a cracked open PVC valve but like the farthest point of introduction better.

[delivron]

I was recently asked if a sap ladder was a wise investment on 14 trees vs a gravity line. Knowing that the producer had a old dairy pump the answer was a definite no. He would loose about 7% of his production because of reduced vacuum on and estimated 1200 trees. In general here is a formula on using reverse slope extractors or sap lifts.

(Inches of vacuum * 12))/12 = maximum lift in feet. Reduce by 5' for reserve and fluctuation for vacuum leaks.

Remember both devices have a cost involved in the fact they use CFM. Ideally you need 1 CFM per 100 trees without ladders and reverse slop extractors. An ideal goal is 24 in of vacuum. Every inch over 16 inches results in 5% gain in sap. Keep the goal of 24" in mind as you select vacuum pumps and other CFM robbing devices in the woods.

[DrTimPerkins]

I was recently asked if a sap ladder was a wise investment on 14 trees vs a gravity line. Knowing that the producer had a old dairy pump the answer was a definite no. He would loose about 7% of his production because of reduced vacuum on and estimated 1200 trees. In general here is a formula on using reverse slope extractors or sap lifts.
.....
Every inch over 16 inches results in 5% gain in sap. Keep the goal of 24" in mind as you select vacuum pumps and other CFM robbing devices in the woods.

Excellent points. Only clarification I would make it that the gain in sap yield is in the range of 5-7% for each inch of Hg above about 15" Hg. The earlier estimate (5%) was based on research completed before sanitation was recognized to be so important. With good sanitation practices, the gain is slightly higher.

[jrgagne99]

How much increase in sap yeild do you get for every inHg between 0 to 15 inHg, assuming good sanitation practices?

[bowhunter]

See the graph on the second slide.
http://www.uvm.edu/~pmrc/SapVac.pdf

[BreezyHill]

7895Sorry I have been busy. Let me share a few things.

Don't discount a "dairy pump". I use a Delaval 73 this past season, my dad used a surge piston style since '76 or '77. I run 27" at the releaser, surge stainless dump tank, and 24-25" at the end of a single 3/4" over 850' running 140-150 taps. The ladders running 80 taps on a single star. This line will be changed to a wet dry with a 1" wet line and have another 250 taps added. The other line will have around 100 added so we are tapping the that bush fully as well. I have no doubt the D 73 will handle it just fine; but there will be a Delaval 75 plumbed since there is another bush with 2000' of mains to get another 300 taps. 75 will only run until level reaches preset cut out setting. When our lines freeze the pump runs the vac gauge up to 29".
When looking at releasers you may want to look at a dairy Jar and pump. They use no vacuum, as the pump forces open a flapper valve with the pumped sap that heads to storage tank. No if you can spare a tiny amount of vacuum you can look at the old surge vacuum dump tank system from the 1940's...they use a two flapper valves, inlet and outlet, and a vacuum line that is connect to a probe in the tank to a relief valve that only dumps the space left empty in the tank and the short length of line. This is about 1/8th of a cfm each dump. Since it is usually close proximity to the pump it is not much of a draw on the pumps cfms.

The pic is of a leaker that was moved to an end from near a ladder. The CV was added to stop any sap from leaking out when the main froze...this failed, it produced a huge wet area on the ground, but I kept it on to prevent mud wasps from filling the valve opening during summer.
The simple way to calculate the maximum lift is check you vacuum level...this is your maximum lift. Our old system had one 26' ladder. When it was taken down by a tree I replaced the system with a 12 & 14'...simple because I hate climbing a ladder that high and lugging it to the woods, across a brook really sucks. The 24' ladder is much lighter and easy to carry.

I tried the pvc valve and lost vac level. Then tried a 28 ga needle and it was to much also. The 1/8" needle valve at a quarter turn open works the best for me. It is best to slip the tubing on at the house by using hot water to soften.

Back to the dairy pump...many have been confused by the vacuum controller that is found on all dairy pumps... this is used to reduce the vacuum level of these pumps to usually 14 to 18". Many have kept these in the system, not realizing there purpose. Take them out and sell on ebay...goat farmers need these and pay good $$$ for them. This often explains poor performance of dairy pumps. Some have even added extra weights to achieve higher vacuum. Any pump that can put 21-22 inches at the end of 150' plus of 5/16 with 30 taps cant be bad ad that is where the leaker pic is from. I have also checked the gauge annually for reliability.

hope this helps

Ben

[BreezyHill]

Oops...the capped y is for a vacuum gauge...use a set of vise grips with teeth removed to pinch tube to not loose the vacuum on the line. A shot with a mig wielder and a moment with a grinder removes teeth real well. Be sure to be patient and give a few minutes for the vacuum to equalize from any changes. My experience is that the best valve setting is the one that gives you the highest vacuum at the end of the line. Since the sap is pulled up the ladder better the vacuum will be higher. When to much leak is achieved vacuum will drop as the air is free flowing thru the tubing.
Also I only set leakers at high flow times...as I do not have time to adjust multiple times daily. The minuet amount of air difference I am sure does affect flow a wee bit but these are all trees that would not be tapped otherwise.

[TunbridgeDave]

I made our first ladder last season and it worked quite well. I had about 70 taps on a single 6-way star setup and lifted it 10 ft. This ladder was at the farthest point, about 1.5 miles and 850 ft gain in elevation, from the sugarhouse. I debated a long time about the "leak" and tried with and without. Without a leak and a very tight installation I got 24" of vac just before the ladder, and 20" at the last tap past the ladder. When introducing the leak I used the drain valve just below the lower star and after days of fiddling with it to get the best result, I could achieve 22" at the last tap without a significant drop in the rest of the system. It seemed to take quite a bit of air to do it though. If I didn't let enough air in, the whole setup (ladder and beyond) would go through a cycle of filling up with sap completely and then the air would push through emptying all the lines. Then it would fill up with sap again and repeat. I decided this cycling probably wasn't a good situation and the leak required to get a 2" increase in vac wasn't worth it when it compromises the vac on the rest of my lines.

The bottom line is I got 20" of vac on 70 taps that I wouldn't have otherwise gotten.

[TunbridgeDave]

One thing about vacuum that I want to say, is it will transfer through liquid if that liquid is moving.

[unc23win]

TunbridgeDave

Just wondering what is the CFM of your pump? I am considering a ladder to pick up a few more taps. It seems to me that you got pretty good numbers as far sap production. I too think I would prefer to deal with slightly less vacuum and not have to mess with adjusting for leaks. Although I am considering running my ladder on a seperate system.

[maple flats]

I know some say only use sap ladders as a last choice, others say they work fine. Some say add a touch of air others say that silly you only lose vacuum when you add air.

So who has done:
1. Used sap ladder and feel it is the right answer for their set up.
2.Used sap ladder and feel it was the wrong answer for their set up and removed it.
3.Would never use a sap ladder even if that was the only cost affective way to have vacuum and stayed with gravity instead.

What is the most rise anyone has on one main and how many steps?

My sugar bush slope away from everything so sap ladder would save alot if they work.
Trailguy, I think the first thing to check is the lay of the land. If I read your post correctly, everything runs down hill from the sugarhouse. If that is the case, you may be far better off if you run your lines to the low spot and then pump the sap back to the sugarhouse in one transfer line. If this is what you do, be sure to design the TF line to drain back so you don't have a frozen TF line and a tank full of sap.
However, I have 3 sap ladders on one woods that pick up about 150 taps in a 425 tap woods. They could not be picked up without the ladders unless I had 3 more tanks and pick up locations. Just not practical. That system runs on a surge vane pump and a surge vac tank. I run 19" at the tank and get 17" at the farthest end of the ladder. 2 of the ladders are at the end of the line, a 8' and a 9' on 2 separate ladders, 2 mains, the 3rd is at the tank and is only 30" to climb up to enter the tank. That tank is 66" tall and it already sets in an old cellar hole about 5' deep. That ladder only lost 1" vacuum but the line follows an uphill line of roadside trees and the last 2 laterals climb a hill into the woods. I could have gotten 3 more taps if I made a 5' ladder, but decided not to, besides that would have left that main line too close to the ground requiring snow removal to keep it flowing too many times. As it is I need to get that main shoveled out for about 25-30' several times in snowy years already.

[TunbridgeDave]

I've got a 20cfm liquid ring pump. I'm a stickler for keeping things tight. Usually I get 25" of vac at the sugarhouse and 24 at the end of the mains in the woods.

[DrTimPerkins]

One thing about vacuum that I want to say, is it will transfer through liquid if that liquid is moving.

More technically correct, you will achieve better vacuum if air is able to be removed from the system. You need to get the air out to get the best vacuum level. Air will naturally move far faster than liquid. Air moving through the system can be impeded by liquid, which can reduce the vacuum level beyond the liquid (in most cases...natural vacuum is an exception).

[unc23win]

I've got a 20cfm liquid ring pump. I'm a stickler for keeping things tight. Usually I get 25" of vac at the sugarhouse and 24 at the end of the mains in the woods.

Ok thanks I was just curious how much your pump was oversized. Mine is similarly oversized. Having never tried a ladder I was curious to know what to expect for vacuum at the ladder. I am not a fan of a leak as I am not around to adjust.