Sap Lfter acting like a Sap Ladder?

[johnallin]

My CDL sap lifter is no longer filling, tripping the vac release valve and then pumping sap up and out the way it should.

Sap is coming in and immediately being pulled up the vertical lift line like a sap ladder. It normally fills with sap, a float rises and trips a vac release allowing sap to be pulled up the line. When empty, the float drops and the vac release is drawn closed and the process repeats again.

I've got 28"HG at the releaser and would normally see 27-28" HG at the lifter, but it won't get past 22 now. Would a drop in vacuum cause the tank to not fill and trip the vac release valve as designed? That doesn't make sense to me, I would think if vac was low it wouldn't pull uphill at all, but that's all it does now.

I replaced the drain fitting with the rubber disc thinking it wasn't seating and sealing when under vac - nothing changed.
Checked the woods for leaks today and did replace a bad saddle and repaired a few chews. Still no change...

This is making me crazy...any ideas would be appreciated. Thanks.

[DrTimPerkins]

…This is making me crazy…

You seem to have crossed that line long ago John. :lol:

Have never tried the CDL lifter, so can’t help you there. Sorry and good luck with the rest of your season.

[johnallin]

You seem to have crossed that line long ago John. :lol:

Have never tried the CDL lifter, so can’t help you there. Sorry and good luck with the rest of your season.

You have to be crazy to spend an entire afternoon in the woods looking at blue tube strung between trees.
Fred’s been more than supportive with in-stock parts and tips…just too bullheaded to give up and call him in.
Besides he’ll just start drooling over my Clear Press again…gawd it’s an awful site!

[GeneralStark]

I wrestled with one of these lifters for almost a decade... I'm glad it's gone.

You have a leak upstream in the tubing system or somewhere in the lifter, or the float is not working correctly. If you already plugged the drain fitting and are sure there is no leak there check to make sure the float and plunger are working correctly. Also check to make sure the float is not cracked and full of sap.

There are typically only three ways air can get into the chamber... tubing system upstream, drain fitting, and the float/plunger mechanism. Or, there is a broken fitting somewhere or the clear end caps are not seating correctly.

At high vacuum, freezing up can cause the float plunger to not close and allow continuous airflow but I get the sense you're having this issue at warm temps...

[johnallin]

Thanks for the response.
The float is free to move and air tight, and in the lowered position stays clear of the vac release plunger so no issue there that I can see. The chamber is simply not filling with sap.. as fast as it comes in, it gets pulled up the line. Consequently, the float isn't given a chance to move up and trigger the plunger.

I replaced the O rings on the end caps 2 weeks ago, and have no leaks (bubbles) there. I was pulling a solid 27-28" last Sunday and with a full canister could see if I had a leak. Put a new vac release plunger and drain assembly in at the same time...Thanks to Fred for having all the parts in Stock for a Quick Repair by the way. From what I can see there is nothing left to replace. It has to be a leak- just don't know where it is.

Does anyone know what the minimum vacuum is needed for the lifter to work? From what I can see, if I'm less than 26" it's lights out.
Thanks.

[TapTapTap]

It sounds like your dry line bypass isn't providing vacuum around the tank. If the vacuum release valve within the tank is shut off (and not leaking), then the only way to get flow through is if your vacuum is lower on the field side than on the vacuum pump side which would cause the vacuum differential to pull the sap up your line. Otherwise, sap would remain static within the tank and accumulate until the float activates the valves. Do you have a sag in the dry line? It could have accumulated sap or moisture and then restricts the field side vacuum.
Ken

[johnallin]

It sounds like your dry line bypass isn't providing vacuum around the tank. If the vacuum release valve within the tank is shut off (and not leaking), then the only way to get flow through is if your vacuum is lower on the field side than on the vacuum pump side which would cause the vacuum differential to pull the sap up your line. Otherwise, sap would remain static within the tank and accumulate until the float activates the valves. Do you have a sag in the dry line? It could have accumulated sap or moisture and then restricts the field side vacuum.
Ken

Thanks for the response Ken.
I'm certain all fittings on the tank are tight..The dry line bypass is also pulling sap straight up. So, if I understand it right, there must be a leak before the dry line?

I need to find a leak detector..

[TapTapTap]

The dry line bypass is also pulling sap straight up.

I think you're plumbed wrong. You need a vertical separation on the field side dry line bypass of at least 5 ft. That way, the sap can't pull up into dry line before it fills the tank. Then you also need to hump the dryline bypass up above the wet line where it connects on the vacuum pump side of the lifter. Otherwise I don't see how the dryline can pull sap so long as the lifter completes it's cycle.
Ken

[johnallin]

I think you're plumbed wrong. You need a vertical separation on the field side dry line bypass of at least 5 ft. That way, the sap can't pull up into dry line before it fills the tank. Then you also need to hump the dryline bypass up above the wet line where it connects on the vacuum pump side of the lifter. Otherwise I don't see how the dryline can pull sap so long as the lifter completes it's cycle.
Ken

Thanks again for taking the time...I'm on the 4th year with this and up to now it's worked flawlessly.
We run 9 runs of 3/16" (approx 185 taps) and about 500' of 1" main line coming from another woods on 5/16" (about 140 taps) into what used to be called a booster tank. This in turn drops down into the lifter tank and gets pulled up and out when the float rises and trips the plunger to break the vacuum. See pics.

The dry line just started to lift sap this week when the tank would not fill. The evacuation line from the tank is now constantly pulling sap; the dry line is doing the same with a heavy run...the tank should be cycling once every 5-8 minutes. I think you had the answer this morning - under vacuum the sap should just fall into the tank, with a leak it's riding the air on up the line just like a sap ladder.
I just need to find the leak.
Thanks again by the way.
http://mapletrader.com/community/attachment.php?attachmentid=22946&stc=1http://mapletrader.com/community/attachment.php?attachmentid=22947&stc=1http://mapletrader.com/community/attachment.php?attachmentid=22948&stc=1

[TapTapTap]

The photos are helpful but it's not clear which line is meant to be the dryline bypass. It looks like the green line is your mainline coming into the manifold above the lifter, along with a bunch of laterals. And the light blue (vs. the purple blue) line is a dryline. If this is the case then it seems like the dryline bypass should run further upstream of the manifold and it should completely bypass the manifold and lifter. Instead, it should run up above the mainline on the vacuum pump side, including a loop above that mainline.

Also, CDL recommends five feet of elevation difference from the lower side of the bypass connection to the lower mainline for each 100 taps. I think this is to provide storage capacity in the line as the lifter is discharging. Your manifold will serve the same purpose. But if you added taps this season then it would explain why you have problems this year but not previously.

I'm also wondering if the connection from the manifold to the lifter is partly blocked causing the sap to back up to the bypass.


Ken

[johnallin]

The photos are helpful but it's not clear which line is meant to be the dryline bypass. It looks like the green line is your mainline coming into the manifold above the lifter, along with a bunch of laterals. And the light blue (vs. the purple blue) line is a dryline. If this is the case then it seems like the dryline bypass should run further upstream of the manifold and it should completely bypass the manifold and lifter. Instead, it should run up above the mainline on the vacuum pump side, including a loop above that mainline.

Also, CDL recommends five feet of elevation difference from the lower side of the bypass connection to the lower mainline for each 100 taps. I think this is to provide storage capacity in the line as the lifter is discharging. Your manifold will serve the same purpose. But if you added taps this season then it would explain why you have problems this year but not previously.

I'm also wondering if the connection from the manifold to the lifter is partly blocked causing the sap to back up to the bypass.
Ken

In the picture, the dryline is marked with red, lifter line in yellow. Dryline is off the "Y" fitting at the end of the green mainline. The other two coming off the mainline dump into the manifold.
Not sure if the second is needed, but that's the way it was designed. Number of taps has not changed significantly since last year...maybe 15-20 added. The manifold does not fill, it just pours into the lifter.

http://mapletrader.com/community/attachment.php?attachmentid=22952&stc=1

[GeneralStark]

I don't think there is anything wrong with your plumbing, especially given the fact that the system has worked for several years. You could probably just run the dry line into the manifold directly and do the same with the green mainline but that's not going to fix your issue. It would just simplify things. You have a leak somewhere upstream of the lifter, and probably a good sized one. You'll have to go over the all the 3/16 lines and everything on the green mainline. I would also suspect that union between the manifold and lifter and any other fitting upstream of the lifter. I have had cracked unions and it looks like you have a stainless nipple there which can be problematic.....

It looks as though you have valves on the 3/16 lines so that should help isolate potential leaks there. Valves on the other lines coming into the manifold would also help.

My lifter was set up similar with a manifold (booster) and dedicated dryline to the manifold. There were four 3/4 mainlines coming into the manifold for a total of about 200 taps. Each line was valved and this made finding leaks much easier. I often ran into the same issue you're having when there leaks on the 3/4 lines. Shutting off all the valves confirmed there was no issue at the lifter, which occasionally there was. The drain valve (i plugged it) was a frequent leaker....I don't shut off the vacuum and kept the lifter and manifold in a heated enclosure.

These lifters are really pretty basic as long as there is no air coming into the system which will bypass the float and plunger (as you are experiencing)...As you know, the lift occurs when the leak is introduced by the float and plunger. If the leak is somewhere upstream, the same thing is going to happen without the float and plunger doing it. It will still function correctly with a small leak upstream but there is a fine line.... your leak is too big.

One question... when you say "The dry line bypass is also pulling sap straight up", what are you referring to as the "dry line bypass"? The float/plunger plug or one of the lines coming into the manifold off the dry line?

[johnallin]

Thanks for the response.
The dryline bypass I refer to is the one with the red arrow. It is also pulling straight up from the end of the green main line, as is the return line from the lifter (marked with a yellow arrow).

You're right that I have SS ball valves at each 3/16 line and have closed them with no change in vacuum.

Essentially the Dry line and green mainline do run directly into the manifold. Dry comes in from the top of the high return line to the releaser (like a whip) and goes to the "Y" at the end of the green main line. There is a blue line at this "Y" that goes straight to the manifold. There is a "T" just before that with another line dropping from the green main line down to the manifold.

Going to try a CDL leak detector from Fred and see what I can find...but we're pulling lots of sap as it is and I just don't have time to start tearing everything apart.
I've already wasted two days monkeying around and I'm done with that. If it finds the leak I'm buying the detector and will repair whatever it is when I have time.

[GeneralStark]

Seems as though a walk out that green line is the thing to do. The air (from the leak) is following the path of least resistance back to the releaser and is carrying sap with it up that line labeled in red.

[TapTapTap]

Don't forget that the Hg will drop about 1" per each 13"of sap that is drawn up the tubes. Or about 1 inch of vacuum drop per 1 foot of sap lift. So if you're pulling a 8 ft sap column then it will drop about 8" of vacuum at the bottom side.

And, if you have a serious leak the the most obvious place to see are those lines that are pulling the sap. The air would be boiling through them in an obvious way.

Ken

[johnallin]

Seems as though a walk out that green line is the thing to do. The air (from the leak) is following the path of least resistance back to the releaser and is carrying sap with it up that line labeled in red.

Plan is to check the "Y" and "T" fittings, manifold and lifter with the leak detector first.
There are multiple possibilities right there, hopefully that's where my problem is.


Don't forget that the Hg will drop about 1" per each 13"of sap that is drawn up the tubes. Or about 1 inch of vacuum drop per 1 foot of sap lift. So if you're pulling a 8 ft sap column then it will drop about 8" of vacuum at the bottom side.
And, if you have a serious leak the the most obvious place to see are those lines that are pulling the sap. The air would be boiling through them in an obvious way. Ken

I think your right and plan to check there first. Will let you know how the leak detector performs..

Hey - thanks again to both of you. John

[TapTapTap]

Plan is to check the "Y" and "T" fittings, manifold and lifter with the leak detector first.
There are multiple possibilities right there, hopefully that's where my problem is.



I think your right and plan to check there first. Will let you know how the leak detector performs..

Hey - thanks again to both of you. John

Thanks for providing an interesting problem to think about.

If all else fails to reveal a solution, then I recommend installing a series of isolation valves around the perimeter of your setup. This would allow you to better diagnose the problem, drain back the flooded lines, and make it so that you can do a startup from zero vacuum without shutting down your entire woods. It would also make it easier to do a quick cleaning or maintenance during the season.

I'm still inclined to think that it's not about a vacuum leak. As I indicated previously, the action in the lines filled with sap would make it obvious if there was a substantial leak upstream. When my sap ladders first come on-line they will shake, bounce, and swoosh from air moving through.

Ken

[johnallin]

Well the leak detector works!
Ended being the stainless Y and T fittings.
Thing went off like Jimmy Hendrix playing Purple Haze…
I’m buying this tool. Pics attached.
First pic shows the T with detector flashing red.
Second picture shows dry line with frost from the leak
Thanks again for the replies and Fred for letting me trial it… making up for all the bad Clear Press comments I think.
http://mapletrader.com/community/attachment.php?attachmentid=22964&stc=1 http://mapletrader.com/community/attachment.php?attachmentid=22965&stc=1

[fred]

making up for all the bad Clear Press comments I think.
22964 22965

Well my feelings are still healing, it may be a long process.

[johnallin]

Well my feelings are still healing, it may be a long process.

... just remember..."dont take life too serious, nobody gets out alive anyways" <grin>

[TapTapTap]

It sounds like your dry line bypass isn't providing vacuum around the tank. If the vacuum release valve within the tank is shut off (and not leaking), then the only way to get flow through is if your vacuum is lower on the field side than on the vacuum pump side which would cause the vacuum differential to pull the sap up your line. Otherwise, sap would remain static within the tank and accumulate until the float activates the valves. Do you have a sag in the dry line? It could have accumulated sap or moisture and then restricts the field side vacuum.


My first guess was right? If so, I should have stopped while I was ahead!

Congratulations on solving the mystery. I'll look into that device.

Ken

[johnallin]

My first guess was right? If so, I should have stopped while I was ahead!

Congratulations on solving the mystery. I'll look into that device.

Ken


Ken you nailed it and thanks again.
But have to say after using the Leak Detector, I cant imagine not having this in my tool bag.
Having wasted 2 days trying to track down the leaks and this "Gizmo" finds them in 2 minutes?
I am more than amazed and can't wait to walk the rest of my lines this weekend.

[johnallin]

Thought I’d post a pic of the CDL Leak Finder for anyone interested.
May cost a few $, but it’s an amazing time saver, more importantly, it Works!
I wear hearing aids - too much rock and roll in my youth? - nonetheless it’s just amazing to me how easy it was to find the leak(s).
I value my time and 2 days “mucking around” trying to find the problem…solved in 5 minutes.

Again thanks to Ken and Gen Stark for chipping in.
Fred…. Thanks for having it in stock.

22968

[mainebackswoodssyrup]

That’s awesome how good it worked for you. Do they have these in the CDL catalog? Did I miss it?

[fred]

That’s awesome how good it worked for you. Do they have these in the CDL catalog? Did I miss it?

Not available anymore through maple. They have them out there for $700+

[TapTapTap]

Not available anymore through maple. They have them out there for $700+


There's one on Northeast Maple Equipment Swap for $300.

https://www.facebook.com/groups/1716013061949461/

[johnallin]

There's one on Northeast Maple Equipment Swap for $300.

https://www.facebook.com/groups/1716013061949461/

Ken, if you’re thinking of one…buy it. I was able to find 2 major leaks today with mine.
One at the lifter - as expected. Turned out it was a 1/4” split in the blue lifter line under a hose clamp. I’d looked at it for 2 weeks and still missed it. Other was a bad saddle. In both cases the detector went off about 8’ away like a gieger (sp) counter. This is my new favorite toy…sure beats guessing and walking around like a Luddite.
And thanks to Fred and Jenn for stocking CDL equipment in this area. Nobody works any harder… period.

[mainebackswoodssyrup]

I hope Ken gets one if he wants one but that leak detector is headed to Peru :cool: Thanks for posting Ken, it would have saved us some time walking Sunday. I imagine this will be my new favorite toy as well. Looking forward to checking our lines with it. Should come in handy when we set up real vacuum after the new shack is built.

[johnallin]

I hope Ken gets one if he wants one but that leak detector is headed to Peru :cool: Thanks for posting Ken, it would have saved us some time walking Sunday. I imagine this will be my new favorite toy as well. Looking forward to checking our lines with it. Should come in handy when we set up real vacuum after the new shack is built.

You'll find it's a super time saver.