Sap Ladders too steep?

[neil2fish]

We have 3 ladders at 10' and one at 11', all in sequence for a 41' lift. we have 3 sets of stars on each. we have 25" vac at the top of the ladder but can't get much more than 15 through to the other side and some times get none. When the ladders are lifting, the sap seems to surge down the line in big slugs and I believe that is what is blocking my vacuum. We currently have them installed at 2% grade and I'm wondering if that's too steep and causing the pooling and surging. Would 1% be better so the sap kinda lays in the bottom of the pipe...?

[Maple Man 85]

Don't know how many tap you have but it sounds like you may need more stars in order to get proper vacuum transfer.

[maple flats]

Do not make a slope on the sap ladders, with a slope, the sap falls down while the air (gases) rise along the top of the sloped tube(s).. You will do fine if you add a 1/8" needle valve about 30-40' before a sap ladder. Then open it just enough to make the sap ladder work good. If you have 3 sap ladders in a row, on thew same main, try adding the needle valve on the furthest out ladders first. Often, just one on the lowest ladder will make all ladders after that hum with sap rising up the ladders. A ladder works best with that tiny amount of air for the sap to ride up. Keep the needle valve open only enough to make it work properly. The 30-430' away, gets the air into the sap and at that distance you will be able to see the response as the sap climbs. The tubes will dance when they work right.
You should be able to get over 20", maybe even over 21" past the ladders when they are functioning properly. That tiny induced air leak gets results you can see. Adjust the needle valve on a heavy flow day, then leave it that way for the rest of the season.

[Ontario Ian]

i'm wondering to how many taps you have on the lifter?

[neil2fish]

Thanks for the replies fellas. We have 200 taps on a one inch main line coming to the bottom of the ladder.. Dave, the slope I'm referring to is on the horizontals. Our verticals are as near straight up and down as we can get them. We also have needle valves on each horizontal section and have played with them to varying degrees of success. We do get those babies jumping and can see the sap flowing. What concerns me is the big slug of sap that comes in waves and I believe it is blocking vacuum when the line is full There is no space above the sap to transfer vacuum. would flattening out the horizontals to 1 degree pitch keep the sap from running to the end and bunching up?

[maple flats]

How many CFM is your pump? What is the slope leading to each sap ladder?
The woods at my sugarhouse is rather flat. (that's why I call myself "maple flats"). My pump is an old BB4 pump and I'm pulling from a total of only 170 taps. I have a vacuum gauge at the far end of both mains. I run the pump at 25-26" vacuum and at the gauges (after installing the needle valves) I get 21-23". My mains only have a slope of about 1.5-2% (and in many areas on my main woods there are sections where the slope is similar)
Maybe the pump isn't keeping up, or maybe you need to tweak the needle valves. If your lines are often full, you may need to add another line as a dry line. Generally, a wet/dry system does not have laterals entering the wet line, they enter only on the mains that branch off from the wet line, but just try adding another 1" line above what you have and that may help.

[Ontario Ian]

I forget how many taps a star is good for, you may need to add some 3 sounds a little low. if you always have 25 at the top I would say your pump and line are fine. you could switch from stars to pipe, you could get away with a 2 pipe probably.

[BreezyHill]

Been here.

I have 7 ladders in a series. 18' tallest and shortest as I recall is 12'.

2% is best I found. what you need is an injector, after the ladder that is having the pooling issue.

Vacuum will not pass thru the pooled sap well at all. So what we need to do is get the sap flowing up the risers at a good speed but with stars, not so fast that it shoots across the star and down the opposite side and just sits and recycles.

So name the ladder closest to the pump #1 and the last #4.

If #1 is running well then we are good to move to #2 if the sap is not flowing as well her as in #1 then we need to motivate it.

To motivate the sap up the ladder we will give it a ride on a bubble of air. This is done with a 1/8" needle valve on a saddle on the main line or if you are adding more sap to the line it can be on a lateral line. I prefer on the main but your choice...I do it both ways but think you will have higher vac on the lateral if there is no injector there.

The slug is a perpetuating occurrence. If you look very closely at your mainline feeding the ladder the slug will cause the line to dip and move down the main to the releaser or the next ladder. The dip in the line causes the slug to fill the line totally and blocks vac transfer and slows or stops the lift momentarily. Then vac is restored and another gulp of sap enteres the main to repeat the process. I have seen these slugs occur in 10 second intervals to even 30 seconds.
It is a sign of two issues:
1 main is a little to loose...I side tie the main with rapid tie from cdl and the slugs will subside.
2 the ladder is not providing a steady flow of sap to the main. Even a slightly loose main will not slug if the sap from the ladder is being pushed up the ladder on enough bubbles to keep the flow steady.

If you have pooling at the base of a ladder you have done a great job of keeping leaks prevented and now you need a tiny tiny amount of air into the system to push the sap up the riser.

Most of my injectors are opened to 1/4 turn open and closed back to 1/8 turn. If you don't go far enough to pull the needle off the valves seat it will still be closed at 1/8 turn open.

Do not hesitate to ask any thing about ladders! They are great tools to get sap to the tank and there is no stupid questions.

I try to explain the reason the issue has come about so that it can be corrected for next season. So it is hard to give a short answer.

Prevention is worth a pound of cure.

[neil2fish]

Thanks Ben, what you've explained is consistent with what I see A couple of our mains are long and could use some side tie. #4 is anchored to a cherry tree and we've noticed it bent the tree and put slack in the wire. That would account for the slugging. We think we're pretty tight and we do have pooling at the base so a little air it is...

[pls009]

Been here.

I have 7 ladders in a series. 18' tallest and shortest as I recall is 12'.

2% is best I found. what you need is an injector, after the ladder that is having the pooling issue.

Vacuum will not pass thru the pooled sap well at all. So what we need to do is get the sap flowing up the risers at a good speed but with stars, not so fast that it shoots across the star and down the opposite side and just sits and recycles.

So name the ladder closest to the pump #1 and the last #4.

If #1 is running well then we are good to move to #2 if the sap is not flowing as well her as in #1 then we need to motivate it.


To motivate the sap up the ladder we will give it a ride on a bubble of air. This is done with a 1/8" needle valve on a saddle on the main line or if you are adding more sap to the line it can be on a lateral line. I prefer on the main but your choice...I do it both ways but think you will have higher vac on the lateral if there is no injector there.

The slug is a perpetuating occurrence. If you look very closely at your mainline feeding the ladder the slug will cause the line to dip and move down the main to the releaser or the next ladder. The dip in the line causes the slug to fill the line totally and blocks vac transfer and slows or stops the lift momentarily. Then vac is restored and another gulp of sap enteres the main to repeat the process. I have seen these slugs occur in 10 second intervals to even 30 seconds.
It is a sign of two issues:
1 main is a little to loose...I side tie the main with rapid tie from cdl and the slugs will subside.
2 the ladder is not providing a steady flow of sap to the main. Even a slightly loose main will not slug if the sap from the ladder is being pushed up the ladder on enough bubbles to keep the flow steady.

If you have pooling at the base of a ladder you have done a great job of keeping leaks prevented and now you need a tiny tiny amount of air into the system to push the sap up the riser.

Most of my injectors are opened to 1/4 turn open and closed back to 1/8 turn. If you don't go far enough to pull the needle off the valves seat it will still be closed at 1/8 turn open.

Do not hesitate to ask any thing about ladders! They are great tools to get sap to the tank and there is no stupid questions.

I try to explain the reason the issue has come about so that it can be corrected for next season. So it is hard to give a short answer.

Prevention is worth a pound of cure.



Ben, do you uss a needle valve after every ladder or just the end one?

[Flat Lander Sugaring]

thanks Ben, Went to Hoosick Falls 1.5 week ago didnt see any steam, my work van usually migrates towards steam in the spring and when that happen I tell the GPS Nazi at the office that thats the way my GPS took and and when you saw the van stop I was asking for directions :lol:

[OGDENS SUGAR BUSH]

I had the same issue, I installed a dry line to the 1st ladder and that helped with some transfer of vac

[pls009]

Anyone that uses air injectors, do you use one after each ladder or just at the last ladder? Thanks

[BreezyHill]

I use injector(s) as needed.

Need is based on if a ladder has a pool of sap at the base that is not cleared.

These pools of sap will limit if not stop the transfer of vacuum.

please feel free to send me a pm to let me know that somebody needs help.

Flat lander, I am sidelined this season by a drunk driver that t boned our Ford Explorer back on july 16. Broken back right shoulder was torn up, broken ribs bruised lung, spleen, intestines, liver, and blew my left hip out of joint, and a TBI. I can remember prior to the accident just fine but since...well I can have a drink in my hand one minute and not even remember having the next. I am much better now but the bad days seem to be worse as I regress to a point of not recalling. From the outside I look mostly normal. Talk to me for a bit and it is obvious. Long road ahead and in a year or two I will be as good as it gets. 5 hours at our new store is my max or the next day is a bad day.

Every day on this side of the grass is a good day! Thank God and those you love for you never know...Life can change in the blink of an eye.

As luck would have it half mile from the intersection sat 8 ambulances at a scene of a leaking RR car. Half mile past was a fire station with a crew on stand by that was watching a thunderstorm rolling slowly in and making a beautiful light display in the sky. They heard the crash and was there in a minute. 8' the trooper told me a week later. 8' farther into the intersection and we would have all died.

So feel free to email me or PM as I am still limited on how much time I can look at the pc screen.

Injectors are the way to clear a pool. You only need them in ladders in a series if you add several more taps. I like them 30-50 feet from the base of the ladder...need to see the ladder moving and turn it down to provide just enough bubbles to send peak flow up the ladder.

Good Luck!

Feel free to ask for more if I didn't answer the question completely.

Ben

[neil2fish]

update: we have anchored our end lines better and side tied our mains on the ladders to reduce bellies. We have fine tuned our needle valves and have seen vacuum pass through the ladders w 10 inch drop I'm calling that a victory No slugging, nice steady flow throughout, and 12 inches at the farthest tap - we were on buckets 2 years ago...

newest thought is to bring in high pressure, low CFM vacuum to end of line to raise negative pressure but not overcome down hill flow