vacuum leaks ideas on what to check

[maple sapper]

I have a vac system that the pump pulls 24HG. THe system only seems to get up to 15Hg. I have read that vac leaks (smaller ones) will whistle. I dont hear any of that. So, May I have a larger leak? If so, any ideas how to locate it. I have thought about putting isolation valves to close off the branches of the system to check each one individually. But, I am hoping for a method. Maybe pour water on each connection and it may make a noise or get sucked in. I am stumped. Thanks

[tom jr.]

check your branch lines were they come to your mains and see if the sap is moving fast (racing) if its fast u have a leak on that line. sap should crawl to your mains when everything is tight.

[tom jr.]

also look in your releaser for turbulance (sap surging) where your mains come in if its visible somtimes thats a good way to find witch line is leaking

[maple sapper]

AHHHHHHHH that reminds me, I have 3 lateral lines that I had to take down due to waiting for the towns approval. These laterals have the taps plugged into the tee. So this may be a huge area of loss. I notice the sap surging back and forth on one of them. Thank you for that tip.

[mapleack]

Grab a lateral with both hands and bend it so there's a dip that sap collects in. As the others said, if its ripping through there, theres a leak on up the lat., keep doing this as you go and you can isolate what section of the lateral has the leak. If its laying there or moving slow, its fine.

[maple sapper]

I went along and tightened up some fittings and removed a few unused zones (another whole story) and put a loop on those saddle fittings, Then I realized these lamb brand caps I bought dont stop vacuum from sucking air so got rid of those with another loop and still can only seem to get 18-19hg. Keep in mind, the sap is barely running. Does it take time to suck the gasses out of the lines? There is lots of bubbles moving slowly So basicly what Im saying is it will build over time once the gasses have been drawn down to the pump. I dont have any sap in the latterals thats racing like spoken of earlier. One seemed like it was surging back and forth a bit. There are a few that are bone dry. Could this be a cause of low vac. Basicly sucking dry tap holes. I do however expect to see some running in the next few days. So if these lines start getting sap, will the vac increase? Just trying to iron all this out.

[Haynes Forest Products]

Sapper Time is money and not having valves in the branch lines is a loss of both. Valves , valves and more valves. If a tree falls and rips out a section of branch line its easy to be up and running at full vac so get them in and you will have control over the system. Plus during taping you want max vacuum and isolated vacuum so you can find the areas that need repair right away. Valves at the releaser and at every trail crossing and mainline branch.

[Beweller]

Has anyone tried using vacuum grease or vacuum wax on taps and fittings?

No self-respecting physicst would attempt to assemble a vacuum system without vacuum grease and wax.

Food grade may be a question, but properly done little or no grease or wax makes its way into the system.

Wax is applied hot (molten) with the system under vacuum. The wax is drawn into the crevice/pinhole and solidifys there, plugging the leak.

[maple sapper]

Im not sure thats doable in the woods. Maybe in a lab or assembly line, but in the woods?

[maple sapper]

Haynes,

I am definitely putting some zone valves on. I have a 1" main and a hand full of 1/2 stainless steel full port valves. Im not sure I should go that route. That may make a spot for stuff to collect. I will have to check the fittings and diameter difference and see how much of a lip it will make. I think it would be best to go with a 1" valve for the sake of not catching debris or making a spot to grow things in off season months.

[Beweller]

Think grafting wax. It is applied hot in the woods.

[Brent]

I find two kinds of leaks. Type one is a large bubble form the sends a train of bubbles down the line. Those I find can be cured by re-seating the tap in the hole, tapping it in firmly.

The second type it the one that really annoys me.
It produces a foam of tiny bubbles right at a fitting. This is almost always caused by an improperly molded fitting. What they call the parting line in the mold, where the two halves fit together when the plastic is injected, leaves a ridge. The tubing cannot make good contact all the way around the barbs and air leaks in there.
The solutions are
1- cut the fitting out and put in a new one
2- I have had success putting wire ties on. The same ties we use to hang main line to the the high tension wires. Loop the wire around the fitting between the barbs and you position it so the wire so it is 90 degrees from the parting line. As you spin it tight it will squeese in hard on the parting lines on both sides of the fitting and almost always stop the leak. You've got to go very slow as it tightens to get it just tight enough to stop the leak and stop before the wire breaks.
3- I picked up some clamps from our dealer that are like the ones on saddle fittings. These look promising but I will only be trying them today.

The biggest losses on my system are in the tap hole. I am going around to each tree and resetting them all for the 4th time this season. The good news is that every time around I seem to gain an inch of vacuum

[Haynes Forest Products]

Getting good valves can be the differance between why I dont have good vac and things are working great. PVC ball valves are cheap and work well BUT they can leak because of scoring on the ball. They will take a little freezing but can crack and completly seperate:mad: Brass ball valves are the best BUT they can freeze and look fine but they will allow air to leak past even when they are shut so check them. Ball valves that are shut with water/sap in them can push the sides out and leak. The same valve when open will be ok and not leak but when closed will leak. Gate valves because the wont close with ice in them and they leak around the packing after repeaded use. Go with a full port threaded brass ball valve and when done for the season leave it at a 45 degree angle so it doesnt freeze and break.

[maple sapper]

I dont have one piece of brass in my system. I'm a die hard stainless person. Always looks good and cleans up really nice. So knowing how well it cleans up on the outside, tells me its getting cleaned up on the inside as well. My response was should I use the same size valve as the mainline? I am thinkin yes. This will prevent a spot for nasty growth to get established and collect.

[sugarstone]

still can only seem to get 18-19hg. Keep in mind, the sap is barely running. .... There are a few that are bone dry. Could this be a cause of low vac. Basicly sucking dry tap holes. I do however expect to see some running in the next few days. So if these lines start getting sap, will the vac increase? Just trying to iron all this out.

Maintaining 18-19hg is pretty good if you ask me. Not sure if you gain much beyond that to cover increased electricity/fuel/maintenance costs.
Your vac will increase during a good flow of sap. I assume the trees that are dry are on hill tops/south facing and/or older declining trees? A normal thing to occur.
Personally I don't worry about pin-hole leaks. I have other issues that cause vac-decline....

[bigtreemaple]

Beweller,
Tells me more about this vacuum grease and wax idea, I have never heard of it but it sounds injteresting. I have been wondering if there is not some way to improve our yubing installation process. Can the grease be applied to fitting without heat and then it hardens, or would it make the fittings slippery and increase the number of lines that pull apart? Tells us more about the application of the hot wax also, ideas for use in the woods.

[Beweller]

Bigtree,

My technical books are now long gone, so I can't give a reference, but you might try looking in one of the old editions of the Chem Rubber Handbook (officially the "Handbook of Chemistry and Physics"). The newer editions do not contain relevant information.

The greases were low vapor pressure greases. They functioned by filling minor crevices with the viscous grease, preventing air leakage, and also by lubricating joint materials allowing better fitting. In general, the greases are going to reduce the ability of joints to resist pulling apart.

The waxes were low melting point materials with varying degrees of flexibility. I guess the commercial waxes must have been expensive (very low vapor pressure) as I recall a "cheap wax" made by mixing pariffin wax and bee's wax. The molten wax was applied to joints--typically rubber hose and glass tubing-- with a small brush while the system was under vacuum. The liquid was drawn into small leaks where it solidified, plugging the leak.

I have no information on how grease or wax would work in maple applications, but it seems like somewhere someone would have tried it. Where are they?

[maple sapper]

I got a good idea for a new tap design then. So if the leader company is reading this call me and I will take bids on my idea. :lol:
The tap of the future will have a groove in it with a o-ring thats proud of the tap taper on the tap itself. It will be coated with silicone to allow it to slide in easier with out pulling the oring off. Sort of like my membranes on my RO.


COPYRIGHT GREGG KENNEDY (AKA MAPLE SAPPER) 2010

[Brent]

I think putting anything on the tap will impead the natural healing proceess of the tap hole. I'd be letting other folks try that one for a few years before I put any in my trees.

[Brian Ryther]

Maintaining 18-19hg is pretty good if you ask me. Not sure if you gain much beyond that to cover increased electricity/fuel/maintenance costs.
Your vac will increase during a good flow of sap. I assume the trees that are dry are on hill tops/south facing and/or older declining trees? A normal thing to occur.
Personally I don't worry about pin-hole leaks. I have other issues that cause vac-decline....

I am sorry but I need to disagree 100%. Any vac levels below 25" is not acceptable to me. Any leak ... well is a leak. It must be fixed. $20 in misc fittings can make or break a season like the one we are having now. Woods need to be walked during day light hours. Night time is for boiling.

[Sap Sucker]

Definatly agree, We've found a big difference with more vacuum. Much more sap the our ladders work much more smoothly with 26" vs. 22"

[Brent]

This year my little Gast 3/4Hp vane pump pulled 12 -13 inches at the beginning. By the time I had it tightened up it was up to 19"+.

I have a duplicate to it now and next year there will be 2 on line. I want 25" everywhere.

Somewhere, likely here or on the Un of Vermont site I read that every inch of vac is a 5% increase in sap.

[PATheron]

Brent- I know that every inch over 20 is 5% more. Theron

[Russell Lampron]

Vacuum in the teens is kid stuff! A few little leaks add up to a big vacuum loss in a hurry. I have been having good luck using Lapierre fittings and IPL/CDL tubing. I get a lot more sap over 20" than I did below 20"! 18 or 19 inches is unacceptable when the pump is capable of 20 plus.

[DrTimPerkins]

The tap of the future will have a groove in it with a o-ring thats proud of the tap taper on the tap itself.

Sounds like a spout that IPL/CDL tried several years ago....the VacuSpout perhaps. Was not a success.

[farmall h]

[QUOTE=Russell Lampron;111227]Vacuum in the teens is kid stuff!

Russell, do you realize you just made a pun!:lol:

[red maples]

my system is pretty tight. one thing that I found works good is hot water and thermos. using what ever fittings you use if you heat it up in the water sliding on the fitting and quickly tighten the clamps before it cools I feel the grooves on the fitting dig into the plastic a litte better and create a better seal.

And sound!!!! thats a big one unless your right next to the vacuum even then I can here them. but the sound travels though the tubing if I listen at the point of the saddle I and if I hear the hiss I check things there first then walk down the leterals to find the hollow tree or loose tap or oval tap hole or loose fitting it get frustrating because its really alot of walking back and forth and back again and repeat but once you learn what to look for it makes a little easier and when you get to know you system you know where common leaks can occur. and always have that roll of electrical tape handy!!!

[driske]

For 24" Hg. What is a stethoscope? ;)