Category Archives: Tubing & Vacuum Systems

Should I Tap?

Les Ober OSU Extension

I got up this morning and it was 60 degrees. All I could think of was that a lot of my friends who make maple syrup got up, saw the same thing I did and headed straight to the sugarhouse to find their drills. To say the least this is unusually warm for this time of year and it has everyone scratching their head. I also looked at the internet and questions were coming into the OMB about whether it is time to tap. This is topic that will be address in depth at the Ohio Maple Days but due to the early warmup I will give you my take on the subject.

First a little science! To quote New York Maple Specialist Steve Childs we need to know “How Does Sap Happen”. Sap flow is the result of sap rising and falling in the tree through the vascular system of a maple tree known as sapwood. The sap flows to provide nutrients to all of the vegetative growth above ground. Sap flow from the roots to very tips of the branches nourishing the buds that will develop into leaves. This process is on a phonological clock that limits the amount of time that we have to intercept a very small portion of that sap and make it into maple syrup. Once the buds emerge the sap is no longer useable for syrup production. Sap rises because of a variation in spring temperatures that we call the freeze thaw cycle. The tree freezes, this creates a suction that draws nutrients from the roots along with ground water. Once the temperature rises above 32 degrees F, gases begin to form inside the tree. This pushes the sap up the sapwood the tree up into the very tops of the branches. Considerable pressure is produced in the process. In fact that pressure can reach 40 psi. When you drill a hole in the tree sap leaks out into a bucket and continues until the tree quits pushing sap or it freezes again. We can increase that flow by applying vacuum to the tap with a vacuum pump and tubing. If the temperatures stay warm sap flow will gradually decline. Sap can flow up to 72 hours without the repeat of the freeze thaw cycle. Without freezing the sap level in the tree drop below the taphole and the flow will stop. Once the temperatures drop below freezing the whole cycle starts again. This is a very simple explanation of a very complex process.

What else can cause sap to stop flowing from a taphole? Once a taphole is drilled into a tree the maple season clock starts to run. With buckets and open tap holes that window of opportunity is around 4 weeks before the taphole starts to heal up and the sap flow stops. This healing is the result of the taphole being exposed to air and from the growth of bacteria in and around the hole. Air dries out he taphole and supplies oxygen to bacteria that coat the hole with slime that eventually seals off the exposed sap wood. Similar to what happens when you get a cut. Blood flows for a while but eventually it coagulates and the bleeding stops. A vacuum tubing system is different in that the taphole is not exposed directly to the outside air and sap is kept flowing under vacuum for a longer period of time. If operated correctly the hole will be kept free of bacteria for most of the season. This can be accomplished two ways. First you can keep the vacuum running continuously whenever the air temperature is above freezing. This will keep the sap moving keeping the lines clear and the taphole cool. Producers have found that they will gather enough sap during extended warm periods and make enough syrup to pay for the cost of running the pumps during that period of time. The other method is to us a vacuum system with check valves to prevent bacteria laden sap from the lines being pulled back in the tree. A tree will draw sap from the lines just like a hose will siphon water from a tank when you turn the tap off. This bacteria laden sap will aid in healing and shutting down the taphole for the season. The check valve will close when the vacuum is released and it will seal off the tap. I discussed many of these taphole sanitation techniques along with the use of check valves in an earlier post on this blog. A side note; for those of you using a 3/16 gravity system, research at the Cornell Maple Program, shows that because you are generating a higher level of vacuum a pull back into the tree occurs. Preliminary research shows that using a check valve will increase the yield in a 3/16 tubing gravity system. I intend to discuss 3/16 tubing in an article to be published on the OMB at a later date.

Now to answer the question should I tap or not tap during and early warms spell. My suggestion is to obtain all the information you can about upcoming weather patterns. Then look at your system. If you are a small producer or a backyard producer looking for the ideal 30 day window, January is most likely too early to tap. Your taps may dry out and you may miss some of the really good runs in late February or March. You could re-tap but that is hard on the tree and is never recommended. The best approach is to watch the weather and be ready to get those good runs in February and March. For those of us who have vacuum tubing. We can stretch the season with taphole sanitation techniques. Watch the weather and tap when to opportunity arises. You may get some very good early runs. If you are going to tap now make sure you change out your spouts or use check valves. You have to create a closed system at the tree to prevent taphole healing. If you have enough taps consider tapping the side of the woods that runs early now and the late running sections later on, spread the season. The best you can hope for is two months before your taps start to shut down. I have personally kept my taphole open from the 10th of February to the 10th of April with the use of check valves and continuous vacuum operation. No matter what you decide to do it is a gamble, here’s hoping your decisions pays off.  Here is a little additional information that may help to make you decide. NOAA Weather has now released their 3 month forecast for January, February and March. It is now calling for above normal temperatures during the period for Ohio into New England. I will hedge a little but my taps will be in by February 1st.



Filed under Maple Education, Maple Production, Maple Syrup in Ohio, Taphole Sanitation, Tubing & Vacuum Systems

When the Season Comes to an End.

Les Ober

Geauga County OSU Extension


The season has come to an end and now you are faced with the arduous task of cleaning up you maple operation. Where do you start and what do you use? For most of the equipment the answer is simple lots of hot water and elbow grease. A good place to start is with the tanks that hold both sap and syrup. Most are stainless steel and area easy to clean with a high pressure washer. Plastic totes and poly tanks have become popular because they are relatively inexpensive but they are harder to clean. We found that a tank washing tip that will fit on your high pressure washer is a valuable tool. This tool allows you to spray to the side and get into areas that you cannot get into with a standard spray tip. We have also found that you do not want to let plastic totes sit around because the bacteria will build quickly. Clean them immediately. Plastic totes, while affordable, will only last about two or three seasons before the plastic is so contaminated with bacterial spores that you have to discard the bottle and replace it. If you keep poly tanks cleaned down they will last for years. However, if you can afford stainless steel tanks they are the way to go.

The evaporator needs to be sugared off and flushed out as soon as possible. I often flush down the pans with clean water and then refill them with permeate from the RO and let them soak. If permeate e is not available use water. I will drain and refill the pans with clean f water and then add the proper amount of pan cleaner and follow the directions on the label. Once the pan cleaner has done the job I will drain the pans and use a high pressure washer to finish off the job. If I do this process correctly I will end up with pans that look like new. Make sure all of your float boxes are clean and the gaskets are replaced if needed. Soak your auto draw off temperature probe and your hydrometer in a 5% vinegar solution to remove all of film. The thermocouple in the auto draw off probe work best when there is no niter on the probe. Make sure your filter press is cleaned thoroughly and the parts are lubricated with a food grade lubricant. One thing I always do is remove all of the extra filters from the sugarhouse and take them into you house and put them in a place that is dry and rodent free. If you use a filter tank make sure the filters are cleaned and dried thoroughly. If moisture is present they will mold. If they do throw them out and start next year with a new one. Never ring out an Orlon filter, your will break down the fabric causing it to filter poorly.

Ro’s need to be soap washed and thoroughly rinsed immediately after the last time you use them. Make sure all of the permeate is drained out. Once you break down the RO make sure to return your membranes to the storage vessels with a cup of permeate in each one. Once you have everything clean I take the membranes back to my dealer to be sent in for cleaning and testing. There is nothing worse than starting a season with a bad membrane that is passing sugar. Make sure your high pressure pump and your feed pump are free and fully drained. . Inspect the membrane housings get them as dry as possible. Many times with the recirculating motors and pumps on the bottom of the membrane towers dampness can cause the pump shafts to seize and seals to deteriorate.The evaporator and the Ro require the use of chemicals that are incompatible. One is phosphoric acid and the other is a basic soap. Keep them separate and out of the reach of children. Be careful when you mix pan cleaner follow the directions on the label.

The most controversial area when it comes to cleaning is the tubing system. Everybody has their own way of dealing with the miles of tubing stretching through the woods. Over the years I cleaned tubing just about every way possible. We have sucked water, pumped water and air, water, air and tubing cleaner, and just plain no cleaning at all. The water and air worked well until we tried to pump up to steep a grade and had a blowout that had enough force to launch a satellite. Sucking water through the lines, left a lot of liquid in the lines that eventually turned to green snot. We have now hit on a method that seems to work. We pull taps with the vacuum on. When we pull the tap we cut off the old spout and use a line plug developed by the Stars Company from Quebec. This seals the drop line and maintains the vacuum on the system. If done properly the sap in the lateral line will not suck back into the drop line.  We also use a paint marker to mark the old tap hole. This way we will not put next seasons tap on top of an old tap. Once all of the taps are out we back flush the mainlines with clean water. Now we will close all of the main lines, then go to end of each lateral opening them up long enough to pull air through the lines and keeps vacuum on the system. It also removes 80% of the liquid out of the laterals and the mains. At this point we open the ends of the main line and let air in with the vacuum on. Once the vacuum drops to zero shut off the pump.  At some point next fall we will go through and put on new spouts and let the lines air out completely. This system seems excessive but it does work. We had a little green sap at the start of the season but nothing we could not filter out. This could have been avoided by flushing the system in the fall.  Here is a word of caution when it comes to using tubing cleaners. They have to be completely flushed from the lines at some point before the next season. Never use Isopropyl alcohol it is illegal in the United States. The Proctor Research Center has a good a fact sheet on this subject and it is worth reading. Also be aware some cleaners attract Mr. Bushy Tail and his friends, this is never a good thing for tubing operators.

Once you have your system cleaned bring in all of the releasers and clean and sanitize them thoroughly. They are made of PVC Plastic that makes a good home for bacteria. Go over the mechanism and use lubricant provided by the manufacture and lubricate all of the moving parts. The last thing is caring for all of your vacuum pumps and transfer pumps. Change the oil or drain out the water on liquid ring pumps. On the new rotary claw pumps change the oil and fog the pump with a pump oil. You need to make sure rust does not build up. Same is true for Rotary Vane pumps which are more maintenance free but putting some oil on the vanes never hurts. All gasoline motors should be drained and the gasoline replaced with Seafoam or a similar product. Never leave gas with ethanol in the tank. Drain the crank case oil and replace it with fresh motor oil and you are ready to go for next season. Make sure you transfer pumps are drained and stored in a place that does not freeze.


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Filed under end of the season cleanup, Maple Production Tips, Tubing & Vacuum Systems

The Quest for High Vacuum Part 2

Les Ober
Geauga County
Ohio State University Extension

When you bring up the subject of vacuum, one of the first questions producers ask is what size vacuum pump will I need to run my system? They also ask if the old rotary vane pump their grandfather abandon in the barn is good enough? The question I ask them is; what vacuum level do you want to run at today and into the future. As I stated in Part I there are two way to measure vacuum pump performance, inches of mercury and CFM. Inches of Mercury measure the negative pressure produced when air leaves the line. For example if 50% of the air is removed then the inches of mercury should be 15. At 25 inches of mercury approximately 85% of the air has been removes from the lines. CFM on the other hand measures the amount of air being evacuated from the lines measure in cubic feet per minute. Pumps are rated (CFM) on their ability to remove air and this largely determines the size of the pump. Two other factors come into play when comparing vacuum pumps. One is the horsepower rating. As the air is removed from an enclosed area the molecules of air in that air become very sparse. The pump has to work harder as the air becomes thinner. The pump also has to overcome the force of the negative pressure inside that area. This requires more horsepower. A larger CFM rating does this faster but requires more Hp. The other factor is pump speed. If you turn a pump faster your will move more air and will increase the capacity. However, over speeding a pump can cause excessive wear on the pump. To answer the second question first, Grandpas pump is not designed to produce anything over 15 inches of vacuum and that is not high vacuum. Most of the liquid ring, flood vacuum rotary claw and new age rotary vane pumps are designed to run at vacuum levels up to 29 inches. Remember all of the pump ratings and their ability to increase vacuum level are done at the factory removing air from a sealed vessel. From this information a performance curve is developed. What makes this whole process more confusing is that many maple equipment companies are now listing there pump sizes by motor horsepower instead by CFM capacity. As pointed out motor Hp is only one factor determining pump capacity. When questioned about CFM, one dealer told me his pump will develop 11 cfm at 29 inches of vacuum. This has to be a specification taken off of a performance curve taken at the factory. The question I have how likely is that pump will ever reach 29 in of vacuum in a maple system? The fairest comparison should be made when the CFM is measured on a pump being run at 15 inches of vacuum. Otherwise unless you have performance curve data in hand for every pump you are considering how you can make a fair comparison. Will the pump be able to deliver 29 inches in the woods at a higher elevation, hooked to thousands of feet of line that is anything but leak free?

Are the dealers wrong when they tell you that your pump will produce 29 inches vacuum? The answer that question is yes and no. As stated most pumps are capable and have been tested to deliver 29 inches of vacuum. This is clearly shown on the pump performance curve. However because the performance curve is read at the barometric pressure at sea level an adjustment for elevation above sea level needs to be made. For every 1000 feet of elevation you lose 1 inch of vacuum, this means the highest vacuum level achievable at an altitude of 2000 feet is around 28 inches depending on the barometric reading on any given day. So what is going on when a producer tells you that his pump gauge mounted somewhere nears the inlet of you pump is reading 28 inch of vacuum but out in the woods it is 18 in. or less? Is that wrong? The answer to the second question is no. Because of line diameter is restricting the flow (Line Loss), the vacuum pump has the ability remove all of the air from the system within a short distance of the pump inlet. This phenomenon occurs because the pump can pull air out faster than the line can deliver it, thus creating a small area of high vacuum close to the pump. The gauge at the pump measures only the vacuum in that area. This is graphically displayed in the line loss charts used in the Cornell New York State Tubing and vacuum system notebook. A 60 CFM pump set at 15 hg hooked to a 3 “ line can maintain over 40 CFM out to 5000 feet. That same pump hooked to ¾ inch line is incapable of delivering 15 in. of vacuum at 25 feet. This is covered in a previous post; April 24, 2013 How Can I Get More Vacuum Where I Need it? The pump is only one part of the total system. If the line diameter is too small it will reduce the capacity of the pump to remove air. The reality is that the only vacuum reading that counts is the reading that is taken out in the woods at the last tap.

How do you determine the CFM capacity of the pump that will best fit in your operation? The NY State Tubing Vacuum Notebook (NSTVN) written at Cornell University by State Maple Specialist Steve Childs states that to go from 15 inches to 18 inches of vacuum of vacuum you need to increase the CFM capacity of your system by 50%. You start with the number of taps you have on the system. Let’s say you have 3000 taps. You know that for every 100 taps you need 1 CFM to keep up with the air and gases coming into the system primarily from the trees. This means that it would take a least a 30 CFM pump to remove the air that is coming into the system from the outside. The vacuum level under these conditions would be somewhere around 12 Hg. The NSVTN states that for every 1 in of vacuum you will lose 10% of the capacity of the pump. In order to increase that vacuum level to 18 in or beyond you would need to increase the pump size by at least 50 %. That would mean that you would need a 45 CFM pump. This is only 18 inches of vacuum and you want to produce a high vacuum rate of at least 25 inches. This is based on research done at UVM Proctor Research Center you need to have at least 25 in of vacuum in the lines to get near optimum sap production. However to get to 25 in vacuum you would need to add 7 more inches of vacuum. Starting with a 45 CFM pump running at 18 in of vacuum, using the 10% loss for every 1hg gain you would end up with only 13.5 CFM (4.5 X 7 = 31.5 – 45 = 13.5 CFM). If you go to 75 CFM pump it translates 22.5 CFM (7.5 X 7 = 52.5 – 75 = 22.5), which falls 7.5 CFM short. A 100 CFM pump translates to 30 CFM (10 X 7 = 70 – 100= 30), enough to run the 3000 tap woods at 25 in of vacuum. Again all pumps are not created equal motor size and pump revolution speed come into play. These are just guidelines, some systems are easier to operate than other and it depends on well you manage your system for leaks.

Now let’s look at the yield side, again based on research done at UVM Proctor Research Center. In their study determining the yield up to 25 in of vacuum was their goal. The study shows that sap yield doubles when vacuum is taken from 0 to 15 in. From 0 to 15 in. there was a 8 gal per tap increase, from 15 to 20 in. there was a 3 gal increase and from 20 to 25 in. a 2.5 gallon increase. At 25 in. vacuum you have added 14 gallons of sap per tap. However, at 20 in of vacuum you have added 11 gallons of sap.. So what would happen if you settled for working at a lower vacuum level? If you backed down to 22inches of vacuum a 45 CFM pump would deliver 27 CFM just short of the amount needed. Going up to a 60 CFM pump would deliver 36 CFM, adequate to run the woods with some reserve. You would raise your production by 12 gallons per tap per season. That is 80% of your original goal of 14 gallons per tap.

You have now made all of the calculations and are beginning to understand the logic and principal behind setting up a vacuum tubing system. The one thing we did not mention was the importance of reserve vacuum. You also need to factor in the vacuum that is needed to run a manual releaser (at least 5 CFM) and anything else like lifts and vacuum piston pumps. All of these eat up CFM. You do not want to be maxed out on CFM capacity when Mr. Bushy Tail shows up. Factor in another 3 – 5CFM in reserve vacuum and hope he does not bring his relatives. Your system need capacity to recover from leaks and other unforeseen problems and it need to do it as quick as possible. In my small world of maple production I am not comfortable with anything under 35CFM. Here’s why! Our home woods only have 400 taps, the requirement to run those taps is only 4 CFM but I have maxed out a 35 CFM pump. Here is how we did it. First we have long mainlines because the woods is spread out. Secondly most the lines drain to a low point that is totally inaccessible to sap pickup. We use a lift to bring the sap forward to the releaser. We then move the sap from the releaser tank to road via vacuum operated piston pump. No one in their right mind would have put tubing these woods but we did and it works. We maintain 25 inches at the releaser, 22 inches of vacuum at the lift and 18 to 20 inches at the end of the mainlines. I will replace that pump with a bigger one someday but in the meantime we are constantly looking for new innovative ways to conserver vacuum and utilize what we have in the best way possible. Just like everyone else we are spending countless hours looking for what Mr. Bushy Tail and his friends have done to our tubing. I cannot over emphasize the importance maintaining your system. The most important time you will invest in you maple syrup operation will be the time you spend in the woods managing your tubing system.

Footnote: Many producers are successfully rnning their vacuum systems over 25hg. They are successful because their system is properly designed and maintained.

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Filed under Maple Education, Maple Production, Maple Production Tips, Tubing & Vacuum Systems

The Quest for High Vacuum in a Maple Tubing System (Part 1)

Les Ober
Geauga County
OSU Extension

The variety of vacuum pumps on todays market is very extensive. Although vacuum has become a mainstay in maple production our utilization of vacuum pumps and equipment is very small compared to their use in the industrialized world. Maple production is just on the tip of the iceberg when it comes to vacuum utilization. Even though vacuum is used extensively in the maple industry we have only been at it a very short time. For this reason there is a lot of misunderstanding about the laws of physics (Quantium Mechanics) that govern the science of vacuum. The online encyclopedia Wikipedia definesthe word vacuum as “void of matter”. In fact it stems from the latin word vacuus which means vacant. The study of vacuum goes back to the Greek Age and the time of Aristotle. Several basic scientific principals apply when it comes to vacuum. Due to pressure exerted by the earth’s atmosphere (15 lbs per sq. in.) you can only achieve a maximum vacuum level of 29.92 inches of mercury. You actually can only achieve a vacuum level equal to the barometric pressure on any given day at any given location. Barometric pressure changes with the elevation above sea level. Another principal is how we measure vacuum. The level of vacuum is a negative measure (because you are creating a negative pressure inside of a vessel) and is read in inches of Mercury. The rate of air being removed from a vessel by a vacuum pump is measured in cubic feet per minute on an English measurement scale.

Even though it has become the Holy Grail, in the maple industry, the term “High Vacuum” is largely misunderstood. High Vacuum or perfect vacuum exists only at 29.92 in. Hg. This is the highest level of vacuum achievable in our atmosphere and occurs only when every molecule of matter is removed from a vessel. This is extremely hard to achieve because once all of the air is removed there are still other gases that qualify as matter and are very hard to remove. In fact the closest thing to a perfect vacuum only exists in outer space and we are not producing syrup on the moon. Wikipedia states “There are three levels of vacuum achievable with modern vacuum pumps. Low vacuum (vacuum cleaners), Medium Vacuum (achieved with a single pump) and High Vacuum (achieved with multi-staged pumps and measured with an ion- gauge).” As you can see the vacuum we use falls in a range of somewhere between low and medium. Obviously the average maple producer does not live in the scientific world of vacuum, nor does he need to. The reality is that we are not dealing with a closed vessel but rather miles of tubing where the introduction of air occurs at every tap, fitting and squirrel chew. The range that most maple producers should be comfortable with is around 20 in. to 27 in. of vacuum depending on their system and the pump they are using. The reason being is that, this is that all vacuum pumps are not created equal and vary greatly in their ability to produce vacuum. Now this is where the discussion and the debate begin. As I have stated in an earlier post (March 25, 2013 Is it The Pump or The Mainline Size That is Effecting the Performance of Your Tubing System?) the producer must consider the entire system before he decides on the type and size of vacuum pump to use. Even though we are increasing the volumn of sap being produced by increasing the level vacuum closer to 29.92 we need to be more concerned about the ability of the whole system to remove air from the system efficently. Rather than concentrating on achieveing the maximum depth of vacuum we should be paying closer attention to the systems ability to overcome leakage and everyday wear and tear.

There is a wide variety of vacuum pumps that can be used to apply vacuum to a maple tubing system. In fact with the use of 3/16 tubing (based on the research of Tim Wilmot at the Proctor Maple Research Center) you may not even need a vacuum pump to achieve your vacuum goal. Most of the pumps used in the maple industry are adapted from some other type of use. The first pumps came from the dairy industry and were used to milk cows. These were rotary vane pumps that were designed to produce around 16 inches of vacuum. The vacuum was produced as the air trapped between the vanes held in an offset rotor was expelled to the outside via the exhaust. As the vacuum level increases heat is builds as a result the system needs some kind of lubrication to absorb the heat. The pump is lubricated with oil that was contained in an oil reservoir. Once you went above 16 inches the strain on the pump produced more heat that it was designed for. For that reason oil coolers and oil-reclaimers were used to make them more efficient. Bearings need to be lubricated with a precise amount of oil to maintain function. When running above 20 in hg, if any of the above are neglected you are headed for a Chernobyl type melt down. There are commercial rotary vane pumps (running a flood vacuum) on the market that are capable of achieving up to 27inches of vacuum. One of the most popular pumps being used is the liquid ring pump. The liquid ring pump uses an impeller running in a ring of liquid producing close to 29 inches of vacuum. As the air is drawn in it becomes trapped in a compression chamber that is formed between the impeller veins and the liquid. The air is expelled to the outside as the liquid (oil or water) is recycled. These pumps achieve as close to 29 inches of vacuum as any pump on the market. The down side of this type of pump is that a water source is needed and that source needs to be kept above freezing. If oil is used then there are environmental considerations.

One of the most recent pumps to come on the maple scene is the rotary claw pump. The rotary claw will produce 27 inches of vacuum, just under a liquid ring. This is a pump that is designed for continuous duty and one that requires minimal maintenance during the season. The claw runs at a very close tolerance to the chamber and traps air in-between the claws and the chamber and expels it to the outside. A small amount of oil is used lubrication. The downside is that these pumps are very expensive. They are designed to be run year round. Long layover periods may allow the pump to develop a rust layer inside to the pump resulting in excessive air. Because they run at a very close tolerance this may lead to early breakdowns. If you buy a rotary claw you need to fog the pump with anti-oxidation oil in the off season to prevent premature wear.

The last pump is the new age rotary vane pumps that are designed to run continuously and to produce a vacuum of 29 inches. This appears to be a very efficient pump. These pumps are similar in design to the older rotary vane pumps but have very close tolerances. They lubricate with oil but total requirement is minimal. So let’s rate the pumps on their ability to produce high vacuum from top to bottom. At the top is the liquid ring and the new age rotary vane with the edge going to the liquid ring especially one of the two stage models on the market at this time. These pumps will consistently reach 27 to 29 inches of vacuum. Not far behind is the rotary claw which will produce 27 to 28 inches of vacuum. Next is the improved rotary vane with a flood system at 27 inches. At the bottom is bossy’s favorite the old style rotary vain used in milking systems. She liked it because it produced no more than 16 inches of vacuum. Any more and she would send it across the room with one swift kick. No matter what you use you will get more sap from you trees. Collecting maple sap with a vacuum system not only saves time and labor but the vacuum will increase your sap yield by up to between 50 % and 150%. In the next post I will cover things you need to consider before you hook your pump into the system.

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Filed under Maple Education, Maple Production Tips, Tubing & Vacuum Systems

Evaluating and Leasing a Woods for Maple Syrup Production

Les Ober
ANR Coordinator
Geauga Co. OSU Extension

Expansion in the maple syrup producing regions has been in high gear over the last several years. In New England and New York there is little doubt on how and where expansion will occur. In both areas you have mountainsides with 1000’s of maple trees. Much of this land is owned and leased by the government or large private companies. Obtain the operating capital; lease the land run the pipeline down the mountainside to the sugarhouse and you are in business. Ok I realize it is not that simple but it is a lot easier than expanding in Ohio. We have fewer trees, in smaller concentrations, which are spread across the state. There is also the issue of convincing landowners to lease their trees. This can be very difficult to say the least.

Let’s look at the process of leasing trees for maple syrup production. The majority of trees in Ohio are privately owned. Most of the government owned woodland is located in SE Ohio in areas that have never been considered prime maple producing area. Sixty percent of the maple production in Ohio is done in the northeast quadrant of the state. This is an area that has seen increased pressure from urban development and the price of that land reflects developmental value not agricultural value. This often makes it unaffordable for someone to buy a woodlot for maple production. To compound the problem much of this land is owned by “Baby Boomers” who have passed away or are now ready to leave Ohio and transfer ownership to a sibling or a third party. Often the cost of ownership (land tax) or the cost of settling an estate will determine what will happen to the estate. Many times the family is forced to liquidate assets such as timber to offset these expenses. As a result many of our prime sugar bushes have been cut down and lost in the process. Unfortunately in times of duress families do not receive the full market value of the timber as a result of a quick sale to take care of financial obligations. This often compounds the agony of estate settlement. They also do not take the time to explore all of the options for utilizing their woodlot.

Today a profitable maple operation relies heavily on technology to be successful and that includes a vacuum tubing system. Installing a tubing system requires a long term (7 to 10 years) lease. Many landowners are hesitant about entering into this type of agreement for a variety of reasons. One of the primary reasons is that the owner does not want to be bound to a binding contract if something would happen and he had to sell the property. Even if a sale is not forthcoming coming many owners are uncertain about how their actions might impact the next generation. This needs to be a consideration when designing a lease. There need to be an emergency escape clause that protects the rights of both parties. One ways of softening this objection is for the owner to get a substantial financial return for leasing the woods. Consider the fact that an average lease on cropland now starts at $100.00 per acre (this is high for some areas and low for others). This means that woods with 80 taps, renting for $1.00 per tap would be equivalent to many cropland leases. This also this also demonstrates why maple lease rates need to start at $1.00 per tap to keep a woodlot lease comparable to a cropland lease. The only way to determine a rental rate is to accurately estimate the number of taps per acre.

Since the millennium it has become increasingly hard to find an unused sugarbush in prime condition in Ohio. Often times a maple producer hears about a stand of timber that might be available for taping and he decides to look at it and it falls way short of his expectations. I can tell you from experience that I have walked more than one woodlot where the owner was sure he enough trees to make syrup. Yes he did have maple trees but not nearly enough to be economically feasible for maple production. The reason for this is that many of the woodlots are 2nd and 3rd growth timber containing large numbers of smaller trees. Because these woods containing trees that are not ready for a timber harvest due to their size the owner is years away from harvest and potential financial gain. This makes maple syrup production a very viable option that can be attractive to the owner because he can get an immediate financial return from his woodlot. On the other side, the producer is looking at single tap trees and trees that may not immediately be big enough to tap for several years. The long term goal of the producer should be to convince the woodlot owner that maple syrup production is a worthwhile use of his resource resulting in the continuation of the lease over time. If these were large mature maples it would be very difficult to make a case that he could make more money by leasing for maple syrup production. In this case the only chance you have is to increase the rental rate and make a case for selective harvest that will preserve some of the larger trees. In both cases the axiom; “The best way to preserve sugarbush is to tap a sugarbush” , applies.

What are the criteria that I go by to determine the feasibility of transforming a woodlot into a sugarbush? Start with a good layout plan. The producer wants to avoid excessively long mainlines going to trees scattered over a wide area. Slope is important but there are ways to work around slope issues. The most common problem with slope is that the woods often slope away from the collection point. This problem is usually solved with the installation of auxiliary tanks, long pump lines and a transfer pump big enough to handle the volume of sap produced. All of this adds to the cost of installing the tubing. The best way to determine layout is to use a GIS map with contours to find high and low points. If you are lucky enough to find a woodlot where to dominant tree is the sugar maple of tapable size and those trees are dispersed evenly across the landscape, you have found a real Jewel. However, most time you end up with sugar maples mixed in with red maple and other hardwood species. A good sugarbush will average 80 taps per acre. Anything below 50 taps per acre is considered marginal. If it is in a woods that has been previously harvested then size of the tree (smaller than 10 inch cum.) becomes an issue. You need to use an angle gauge or prism to determine size at a distance. For closer examination a 32 inch circumference chain will equate to 10 inch diameter tree. The best way to determine tap numbers is to lay out a circle with a 26.4 inch radius from the center. Count all of the tapable trees in that circle and multiply that number by 20 to give you the number of taps in an acre. Example (in a circle with a 26.4 inch radius) 5 taps X 20 = 100 taps per acre. You want to do this randomly at multiple locations across the woods. Average all the results of those locations together to come up with an average number of taps per acre for the woodlot.

Now it is time to develop a management plan. A well-managed vacuum tubing system should produce ½ gallon of syrup per tap. At $50.00 per gallon that grosses you from $1250 up to $2000.00 per acre. That is a gross return, all of your production expenses including your labor needs to be deducted to give you a net return on you investment and your cost to produce a gallon of syrup. One of those costs is the initial cost of installing your tubing, spread over a 10 year period.. You need to know your cost of production before you can put together a lease offer.
What are the selling points of a good lease? A good lease agreement is built on the premise of Best Management Practices. This includes tree size determination, general tapping practices, access for the owner and operator, BMP responsibility, owner liability protection and finally rent per tap. All of these need to be adapted to the woodlot you are trying to rent. For example the owner depends on the woods as a source for firewood. He has to have access to the woods in the off season. You must lay out your system to allow access. This includes being able to disconnect certain mainlines and removing several laterals to allow for that access. He is also concerned about liability if you or one of your workers gets hurt in the woods while making syrup. You need to include him in your insurance liability policy as a co-insured, taking the risk off of him while you are on his property.

You now have a reasonable lease offer that works for you but will you be able to sell the idea to the landowner. You need to put yourself in the shoes of the landowner and ask yourself would you consider entering into this contract if it were offered to you. Hopefully the answer is yes but if it is not then you need to reassess the plan before moving on. What happens next will determine the success or failure of adding this woodlot to your operation. You now become a salesman trying to convince the owner that this is a good idea and both of you will benefit. If you have done your homework and you make your case honestly and sincerely you should be successful in expanding your maple syrup operation.


Filed under Expansion, leasing, Planning, Sugarbush Management, Tapping, Tubing & Vacuum Systems

For Maple Syrup Producers Fall is a Time for Planning

Les Ober
Geauga County OSU Extension

Without a doubt, fall is my favorite time of the year. It is time when all of the hard work of spring and summer comes to together as you harvest the returns for your efforts. It is also a time when the Maple tree goes into dormancy. This means that the maple syrup season is only a few months away. Fall is the best time of the year for planning and making alterations to your maple sugaring operation. You can take the time to carefully plan out what changes are needed before you start the Spring rush.
As soon as the leaves fall you need to get into the woods and take a good look at your operation. Has there been storm damage to you tubing or are your trails blocked. Many producers already have their sugar wood cut for the 2015 season, however the storm damaged wood can quickly be stock piled for 2016. Major damage to your tubing needs to be repaired this Fall. As you look over the situation it might be a good idea to see if you can improve on your current system. This is a good idea even if you do not have damage. Maybe there was a trouble spot last spring that just did not seem to move sap as well as in the other parts of the woods. If it was at the end of a very long mainline maybe there is a way to shorten up that line. It might be possible by extending a wet/dry line further into the woods or increase the diameter of the existing mainline. It is also a good time to look at how you are distributing your vacuum (CFM’s) across the woods. I covered the allocation method used in the NY State Tubing and Vacuum Notebook in an earlier article (How Do I Get Vacuum Where I Need It) posted under the tag “Vacuum”, on the Ohio Maple Blog. One thing to always keep in mind is that if you make a change to your system be sure that you thoroughly research the impact that the change will have on the entire system. Here is an example of a change that could greatly impact the performance of your vacuum system.

Let’s assume you are running 1000 taps on a 35 CFM Vacuum Pump. Under the present system you are able to supply all of the taps with at least 18 inches of mercury out to the longest line in the woods. If you follow the standard rules for vacuum utilization every 100 taps would utilize 1 cfm. The system works because you are using 10 cfm on the pipeline, 5 cfm to run the vacuum releaser and 2 cfm to counteract the distance from the vacuum pump to the releaser. That is only half of your available CFM. This gives you plenty of vacuum (cfm) to overcome leaks and other problems. Now you decide that you can add 300 taps but to do so you will need to install a sap left that requires no less than 7 CFM to run. In this case, you would be taking away another 10 CFM (lift 7 + 300 taps 3) from the main pipeline. We are now up to 27 CFM utilization. Now with only 8 CFM to spare we will have to be very careful to make sure all of the leaks are sealed and that the pipeline is sized correctly. If not you could be headed for a serious drop in Inches of Mercury on your longest lines. One more word of caution, most Vacuum pump CFM ratings are determined at sea level. We do not run our pumps at sea level. Most sugarbushes in Ohio are 500 to 1000 feet above sea level. This means that you may not have as many available CFMS’ as you thought.

All of this comes into play when you are planning to make changes to your maple sugaring operation especially your vacuum system. If you have questions or want to learn more about maple systems I strongly recommend that you plan on attending the 3rd Annual Lake Erie Maple Expo in Albion Pennsylvania, Friday November 7th and Saturday November 8th. On Friday you will have chance to learn from professionals. If you are installing tubing you will want to attend Jason Grossman’s class on Tubing installation Jason is a sugarmaker and a professional tubing installer. He has installed tubing from Minnesota to Maine and several provinces in Canada. His installation technique is considered to be one of the best in the country. Also on Friday you will have a chance to attend a Vacuum Systems Management Class taught by Steve Childs NY State Maple Syrup Specialist and the author of the NY State Tubing and Vacuum Notebook. This is a must read for anyone using and running a vacuum tubing system. Steve will go over many of the topics that he has written about in his notebook. A full list of the Friday and Saturday programs and registration information will be listed on the LEME page of this b

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The Most Important Time You Will Spend in Your Sugarbush

Les Ober; The Ohio State University Extension Geauga County


               The 2014 maple season is only 45 to 60 days away depending on where you live in Ohio. The Deer season is coming to an end and it will most likely be safe, to once again enter the woods. Mid-December is a great time to inspect lines and to make adjustments to your tubing system. The work you do before the season will probably determine how well your system will perform during the season. Here are some things to consider and watch for as you work on your tubing system prior to tapping.

               How many times have you said to yourself, this system just does not perform as well as it did when we installed it? You have to realize the first year of maple tubing system’s life will be its best year, simply because it is brand new. The spout and drops are new and everything is tight and working properly. After the first year a systems performance will depend on how well it is maintained. Leaks will develop and those leaks can expose flaws in the system. Finding and repairing leaks is the first step to achieving high vacuum. The problem with doing work on lines prior to tapping is that you are not running a vacuum pump making it almost impossible to find all of the leaks. However, with careful inspection you can spot and repair many potential trouble spots that can cause problems later.

                The first step is to walk the wood making sure that all of the lines are up and running tight and straight. Inspect all the tubing that is in contact with tree. These areas are where you will find the highest percentage of squirrel chews. If the critters have been chewing this should be easy to spot. Make sure you not only look for chew holes but also scrapes where the little vermin start to chew and back off for whatever reason. Next you need to look for old connections on tees that have been stretched and twisted, replacing old tees where they are needed. If your system has some age then this year may be a good year to start replacing drops and spouts. Research out of the Cornell University maple program states that you can improve your production by over 50 % when you install new spouts and drops. A couple of interesting side notes are that you can come very close to this by keeping the old dropline and installing a new check valve adapter on that line every year. Many producers are finding it more convenient to replace the spout every year and the drops every third year. Use a different color tubing  on new drops so that you can quickly identify the drops that need to be rotated out.

               Three areas to check on main lines are the saddles, boosters and line connectors. Check for old worn or stretched saddles. If the loop line going to the saddle has become disconnected and is pulling hard on the saddle itself replace the saddle immediately. Once the seal on the saddle is twisted you will more than likely not be able to properly reseat the saddle without leakage.  Saddle leaks are hard to detect and can quickly become the site of major vacuum lose. Another trouble spot are the boosters on a wet dry line. Most of these are made of PVC plastic. PVC plastic was developed for indoor plumbing in buildings. It is not designed to be left in direct sunlight for long periods of time. The result is a total breakdown of the plastic due to Ultra violet light from the suns rays.  The UV Light and exposure to hot and cold will also breakdown the glue in the joints. Any PVC fittings should be inspected and replaced on a regular basis. If you use a PVC line from your vacuum pump to your releaser, including your moisture trap, make sure you inspect this area for loose or cracked joints. These areas are not only exposed to UV light but experience major vibration that can cause damage to the line.

 The other location where vacuum leaks can occur is where lines are joined together with Cam Lock couplings. Producers need to replace the rubber gaskets on the inside of these couplers on a regular basis. Also try not to exert a lot of outward force on these connections. The work best when they couple together with little force.

               Most of the above locations can be inspected without have to run the vacuum. Of course the final inspection will need to be made once the taps are in and the vacuum is running. If you can flush lines with water prior to using them many leaks will appear during this process. However, this may not be possible due to weather conditions. Early inspections and maintenance can offset hours of costly repairs and down time once the season starts.



Filed under Tubing & Vacuum Systems

How Can I Get More Vacuum Where I Need it?

By Les Ober, Geauga County OSU Extension

You have just bought a new vacuum pump and you have spent some time making sure that your vacuum lines are sized properly but for some reason one or two lines are just not preforming the way you want. Is there a solution to this problem?  Yes there is! It is all about distributing the vacuum to where you want it.

            If all of the vacuum lines are the same size and all of them run directly to the releaser all of the CFM’s for each line will be distributed equally across the system. If you have 4 1 inch lines coming to the releaser that is powered by a 60 CFM pump each line would receive 25% of the vacuum or 15 CFM. According to theory that would be enough vacuum to run 1500 taps on each line. However, based on previous articles in this blog you realize that due to line loss this is not entirely true but each line would receive 25 % of what is available. What happens when you have 1 1 ¼ line used in a wet dry system hooked to the releaser along with 3 1 inch single lines.  This is where vacuum distribution comes in and the math starts.

                        Line Allocation

            Each pipe diameter has a cross section area       

            Knowing this will give you the cubic feet capacity per minute for the pipe.

            It will also allow you to assign a percentage of a vacuum pipes capacity to each pipe.   

            Area of the Pipe

            ¾”        .44 sq. inches              1 ½”     1.77 sq. inches

            1.0”     .78 sq. inches              2.0”       3.14 sq. inches

            1 1/4    .1.23 sq. inches          3.0”     7.07 sq. inches

How do I determined what percentage of my vacuum is going to each line?

Let’s say in your woods you have 4 line, three 1 inch lines with 1/3 of my taps on them and one 11/4 over 1 inch Wet / Dry with 2/3 of the taps. Here is a simple formula determine vacuum

:  For the 1 inch lines .78 + .78 + .78 = 2.34

   For the 1 ¼ line                                     = 1.23

                                                                    = 3.57

.78 ÷ 3.57 = .22 or each 1 inch line receives 21 % of the CFMS

All together the 1 inch lines in this system are receiving 63% CFMS

That leaves the remaining 37 % (32CFM) capacity for the 1 1/4 line.

Now you have 2/3 of the taps on the 1 ¼ wet /dry line only receiving 1/3 of the CFM”s. You need to redistribute the CFM’s to the largest number of taps. To correct the problem you need to reduce the number of CFM’s going to the 3, 1 inch lines or you need to increase the size of the dry line on the wet dry system. If you apply the math using the above information you can obtain   the most economical solution;

You could install a 2 inch line in place of the 1 ¼ this would apply 60% of the CFM’s to that line and 40 % to 3, 1 inch lines. You could also bring all three 1 inch lines together into a vacuum booster with a 1 ¼ outlet going to the releaser. What you end up with is two lines coming into the releaser of the same size, each with 50 % of the CFM’s. Remember the wet line does not count as a vacuum line; its only function is to transfer liquid. The only other considerations are to avoid line loss from the vacuum pump to the releaser by using a 2 or three inch line and to account for all the CFM’s used by releasers and other equipment on the system.

All of this information is available in more detail in the New York State Maple Tubing and Vacuum System Notebook from Cornell University, written by Stphen Childs, New York State Maple Specialist. To obtain a copy contact Cornell University, College of Agriculture and Life Sciences, Department of Natural Resources.

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Is it The Pump or The Mainline Size That is Effecting the Performance of Your Tubing System?

Les Ober, Geauga County OSU Extension

           When you start to install a vacuum tubing system you need to understand a few basic principles that determine how air moves through a mainline. First you must consider the line loss. Line loss is caused by the friction of air moving through the line. A general rule of thumb is that the narrower the diameter of the mainline, the slower the air removal at long distances.   The line will restrict the pumps ability to quickly remove vacuum and recover from leakage. If you have a 1000 foot, 1 inch mainline attached to a 60cfm pump you will lose 50% of you CFM’s within the first 200 feet. If you attach the same pump to a 2” line you will lose 50% of your CFM at 1500 feet. Air moves easier through a larger diameter line.

You need to consider how a vacuum pump works. The measure of vacuum pumps efficiency is not how many inches of mercury it can obtain but how many cubic feet of air it can remove from the line in one minute. Remember even the smallest vacuum pump can remove the air from an air tight system and obtain high vacuum if you give it enough time to work. Also remember there is no such thing as an air tight maple tubing system, ability to recover from leakage quickly is critical.  Bigger pumps can remove air from the line faster but only if that air can move down the mainline quickly. If the diameter of the mainline is too small the air flow will be restricted by line loss.

Using the same 1000 ft. mainline, how many taps will it run? Let’s consider a 1 inch line, 1000 feet long hooked to a 60CFM pump. The 1 inch line will only allow 8 cubic feet of air to move through the line in one minute’s time at 1000 feet. If you follow the rule of 1 CFM for every 100 taps that would mean that you could not exceed 800 taps on that line, even though you have a vacuum pump capable of running 6000 taps. The only way to solve this problem is to go to a larger diameter line. If you move up to a 1 1/4 line of the same length hooked to the same pump you would have 12 CFM available at 1000 feet into the woods. You could theoretically run up to 1200 taps on this line. The major problem here is that many producers feel that they can solve their vacuum problems by buying a bigger vacuum pump. The truth is that at 1000 feet, with a 1 inch line, hooked to a 15 CFM, pump is capable of transferring 7 CFM.  If you replace the smaller pump with a much larger pump (60 CFM) it will only be able to transfer 8 CFM. A larger pump under these circumstances will not transfer any more CFM’s. 

               Another factor to consider is that most modern vacuum pumps are capable of maintaining a high level of hg mercury or inches of vacuum. Once a leak develops the vacuum level declines. At that point it is up to vacuum pump to overcome that leak by removing the incoming air. The pump must be able to do the job quickly to maintain an optimum level of performance (high vacuum) . As demonstrated in the above example a big pump can only be as efficient as the line capacity behind it.

               Up to this point we have only considered air flow through an empty line with no sap in it. What happens when we add sap? The optimum goal is to maintain 60% air and 40% liquid inside the vacuum line. What happens during peak flow when the ratio is often reversed? Under low flow conditions there is very little liquid inside you mainline and air can move freely. Under peak flow conditions sap builds up and air blockage often occurs. This blockage could be in the form of waves or even worse slugs of sap that seal off a portion of the line. This is real problem especially on slopes of 2 % or less. The solution to this problem, especially on flat ground or where large volumes of sap are entering the primary mainline from secondary main lines is a dual-line conductor or wet dry line. The bottom line conducts the sap and the top line removes the air from the system. The bottom line is sized based on its liquid capacity and the top line is sized based on air flow and CFM capacity. When figure the CFM capacity for a Wet-Dry system only consider the capacity of top line. The advantage of a wet-dry system is that you should never have liquid in you top line, that means that it will transfer air at full capacity and the bottom line will have more capacity to transfer sap. To get a more in-depth description of how to install a vacuum system, including line loss charts for both single and wet-dry mainline purchase a copy of the New York State Maple Tubing and Vacuum System Notebook from Cornell University, Stephen Childs Author.

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Vacuum an Explanation

Les Ober, Geauga County OSU Extension

 The concept of vacuum is the exact opposite of what most people think of when they see a pump and some lines. Most people think of air being pushed though a line, similar to a compressor with an air line. Air can be compressed to an infinite level as long as what is holding that air does not explode. With vacuum it is the exact opposite .Vacuum is pressure based on the force that the earth’s atmosphere exerts on all of us. This amounts to about 15 pounds per square inch of surface or 29 inches of mercury. This pressure is also referred to as barometric pressure. As the atmosphere fluctuates it will go up and down with atmospheric air movement (weather fronts). If you remove air from a container you will produce a vacuum inside that container. That lack of air creates a negative pressure that is measured in inches of mercury (hg.)  and will never exceed the outside barometric pressure.  As molecules of air are moving toward the pump and that air is ejected at a volume over a period of time. In this case Cubic Feet of air per Minute (CFM) . The capacity of the pump will determine how fast this will happens.  What we are trying to create inside our sap lines is the absence of air or a perfect vacuum.  Most producers grasp these basic concepts they also realize that there is no way to maintain a perfect vacuum inside their sap lines. Damage from wildlife and age introduces air into the system. Even the tree allows air to be introduced. For this reason we always allow for 1 CFM of air movement for every 100 taps. The problem with most systems is that we are getting way more air into the system than we want. This puts a greater burden on the pump to remove the air. The speed at which this is accomplished is largely determined not only by pump capacity, but how the tubing system is constructed. Line length and diameter in relation to the pump and the amount of liquid in the lines has as much to do with it as pump size. Couple this with the fact that most producers are attempting to run at high vacuum ( as close to the daily barometric pressure as possible). The problem with this is that it is counterproductive to pump efficiency. To go from 12 to 15” vacuum requires 20% more system capacity, 12 to 18”Requires 50% more system capacity and from 18 to 20” requires 80% more capacity. Research says you can get more sap per tap, up to 50 % increase. However, this greatly increases the demand on your pump and everything behind the pump has to be in optimum condition. You can see in one short paragraph there is more to running a vacuum system than hooking a line to a pump. 

               The best way to approach designing a vacuum system is to start with the tubing system and put a pump in place that will run that system. To do this, you need to determine how many taps will be on each mainline.  You need to know the slope of those mainlines. Sap flowing in a relatively flat wood will move more slowly than sap moving down a mountain side. Each line has a capacity for liquid it is conducting. For example a 1 inch line on gravity will conduct 50 gallons per hour on a 2% slope and 75 gallons per hour on 6% slope. Remember that you want no more than 40% of the space inside the tubing holding liquid. The rest of space is needed to move air. The vacuum line is dual purpose, but its main function is air movement. If the sap level rises to the point that it blocks that air movement then the vacuum level quickly drops off. This along with excessive leakage is the main reason for vacuum level drop from the pump out into the woods. Using too small a diameter line will result in lines running full of liquid and a drop in vacuum.  One of the best ways to overcome this problem is to use dual-line conductors, using the top line for air movement and the bottom line for liquid. The use of this type of system is vital in flat woods with very little slope. Getting your lines sized correctly is the first step in creating an efficient vacuum system. In the next post we will discuss the importance of vacuum line sizing and distribution.

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