In Line Check Valve

[Alex Davies]

Good day,

Does anyone know if an inline check valve exists for 5/16 or 3/16 tubing? I'm hoping to install check valves on my lateral lines just as they enter the mainline. If so, who makes them?

Thanks

[mol1jb]

Why not just use CV taps?

[Alex Davies]

DOn't want to spend the $$$ to replace 2200 spouts. Thought maybe an inline check valve as the laterals enter mainline might prevent backflow if/when my vac pump shuts off (Running it on gas, and shut offs are inevitable)

[Alex Davies]

Is it just Leader Evap that makes the CV spouts? I'm looking at the CDL catalogue (closest dealer) and not seeing any CV spouts.

[BAP]

Leader Evaporator has exclusive rights to the check valve spouts developed by Dr Tim and the Proctor Maple Research facility.

[mol1jb]

DOn't want to spend the $$$ to replace 2200 spouts. Thought maybe an inline check valve as the laterals enter mainline might prevent backflow if/when my vac pump shuts off (Running it on gas, and shut offs are inevitable)

I thought that the increase in syrup produced outweighed the cost of CV taps. But I suppose that depends on lots of factors such as use of vacuum and line installation.

[Alex Davies]

I thought that the increase in syrup produced outweighed the cost of CV taps. But I suppose that depends on lots of factors such as use of vacuum and line installation.

Yeah, I read that in another thread. And there's probably something to it. However, this season I'm attempting to be a good boy and break my bad habit of maxing out the credit cards before the season starts only to work my arse off the rest of the season to pay it all off.

Anyhow, doesn't sound like an inline check valve exists, as this might have been a fairly inexpensive though maybe not as effective (as installing cv spouts) solution to my problem...

[Haynes Forest Products]

What I believe could be a factor is the design of most of the check valves I have seen. They don't take kindly to freezing liquids. The ones I have seen have a wide body that's glued together and look as though they would hold to much liquid making them easy to crack at the seam when under smaller amounts of stress from ice.

I know when you look at 2200 check valve spouts it sounds daunting but if you have 220 laterals of 10 taps each and spend $3.00 per check valve off Ebay that might work now because you strive for five double that.

Lastly I do believe that the reason CV work as well as they do is the ball check is as close to the tap hole and stops the suck back before the sap ever touches the drop line.

[minehart gap]

Alex, I found 1/4” and 3/8” check valves at a plumbing supply house. Not Lowe’s type store but real supply house. I decided not to buy them so I don’t remember the price.

I do remember that there was a problem with low pressure. Most check valves are spring loaded and do not open until there is 7 pounds of pressure against them

[Alex Davies]

I think I've decided to buy the cv adaptors from leader.

Thanks anyhow

[DrTimPerkins]

I do remember that there was a problem with low pressure. Most check valves are spring loaded and do not open until there is 7 pounds of pressure against them

I tried several types of these before coming up with the final CV adapter/spout design. None worked particularly well due to the "cracking pressure" involved.

[dbeitz1891]

There is inline check valves that are barbed in both 3/16 and 5/16 made by US Plastics. They are based out of Ohio. The operational range is between 1 and 27" of vacuum and have a cracking pressure of only 0.5 psi.
We installed the 3/16 in one of our woods last year and they worked just fine, and our sap yield increased as well. This year we have installed them on all of our laterals.

For those of you asking why not use the cv spouts from leader, the cost difference is made up on only 4 spouts on each lateral by purchasing the in line checks. I'm not saying they work better or worse but strictly at a monetary standpoint the in line checks are much more cost effective.

Only thing you have to be conscientious of is that the checks may plug from debris in your lateral. For those of you running 3/16 line I'm sure you know what I am talking about lol

[DrTimPerkins]

I'm not saying they work better or worse but strictly at a monetary standpoint the in line checks are much more cost effective.

That statement doesn't make logical sense. If you don't know that they work better or worse, then you cannot know whether they are more or less cost effective. What you mean is that they are cheaper. Cheaper does not mean better or more cost effective....it means cheaper. Cost effective means better return at a lower cost. Extending that reasoning means that using a check-valve at the releaser only would be the most cost effective approach.

A cracking pressure of 0.5 psi = 1" Hg. Already you've given up 5-7% of your sap yield on every tree on lines with that style of check-valve.

[sugarsand]

Bought some last after looking on the internet. If remember correctly, found them on ebay in aquarium supplies, very inexpensive, clear plastic with a red valve. These worked fine for us last year.

[dbeitz1891]

That statement doesn't make logical sense. If you don't know that they work better or worse, then you cannot know whether they are more or less cost effective. What you mean is that they are cheaper. Cheaper does not mean better or more cost effective....it means cheaper. Cost effective means better return at a lower cost. Extending that reasoning means that using a check-valve at the releaser only would be the most cost effective approach.

A cracking pressure of 0.5 psi = 1" Hg. Already you've given up 5-7% of your sap yield on every tree on lines with that style of check-valve.

I simply stated that because I did not want to put down Leader, in my opinion they do work just as well as check valve spouts. We had them installed last year and saw an increase in sap yield by about 8%.

When they are doing the same job as check valve spouts but i only have to install 1 per lateral then yes, they are more cost effective. If a check valve at the releaser would work effectively, then yes that would also be more cost effective.

I've heard plenty of bad stories about cv spouts. Nothing in this world is perfect, but we are always trying to improve. This is an avenue which I am exploring to try and save money without sacrificing production. I will let everyone know how they perform this year.

Yesterday it was 32 degrees here and a couple laterals were running and sap was flowing through the check valves. Can I ask how that impedes sap flow when there is sap beneath the check valve pulling them open?

[DrTimPerkins]

Can I ask how that impedes sap flow when there is sap beneath the check valve pulling them open?

A spring-loaded check valve requires a certain amount of "pull" to open it, or "crack" it due to its construction and operating parameters. It is kind of like a door on hinges, it will always want to close unless there is constantly some force acting to keep it open. The force is coming from your vacuum system. If the cracking pressure is 0.5 psi, that equates to a force of approximately 1" Hg. So your vacuum system has to constantly pull 1" Hg on that valve to keep it open. If you're using that 1" Hg to keep the valve open, then you reduce the force of the vacuum by 1" Hg at all points behind that valve. 1" Hg = 5-7% sap production, meaning that any tree behind this style of check-valve will produce, on average, 5-7% less sap. Now having that check-valve there might increase sanitation by reducing backflow, but at the same time, this method does come at a cost. Secondarily, any leak occurring beyond the inline check-valve will affect all other trees on that line, and not prevent sap backflow from the lateral line into any of the tapholes on that line.

Don't get me wrong, I'm not saying that this approach won't provide any benefit. What I am saying is that the benefit also: 1) has some cost (some amount of lost vacuum and lost thus lost production over what you would have with an alternative approach) and 2) that it doesn't provide protection to every taphole on that line the same way that having a check-valve on each tree would have.

My comment was in response to your saying it was "cost effective", presumably compared to the Leader CV system. Since you didn't directly compare them, both in terms of cost and in terms of effectiveness (sap yield), you have no real evidence to base that statement on. Yes, it is a cheaper approach...no question. A bicycle is cheaper than a motorcycle, but which will get you down the road more effectively? That is a very different question.

Now a better approach would be to use a check-valve similar to the type used in the Leader CV adapter/spout because there is no cracking pressure required. The ball floats, it is not spring-loaded, and it responds very quickly to changes in flow direction. This would solve the #1 issue above because there is no loss of vacuum due to needing to overcome the cracking pressure. This approach does not address issue #2 mentioned above.

[dbeitz1891]

The check valves I'm using are not spring loaded, they are floating diaphragms that remain open until closed. I will contact the company to make sure of this.

I understand the leak in the line aspect when trying to protect every tap just looking at a different alternative if it can achieve the same outcome. Just like when you are deciding on how many taps to put on each lateral. It all revolves around how often you are going to check and maintain a "leak free" system.

Now, I understand all of the parameters and variables have to be the same but if this check valve does work as well as check valve spouts, then it is more cost effective. And since they just came out with a 3/16 check valve this year it would be difficult to compare results. Unless of course you went back to 5/16 on your drop and used a 5/16 check valve but that would involve a differing variable when directly comparing the two.

Next year I will install on one woods just check valve spouts and monitor and record sap production. In another woods with same slope, soil conditions, and tree age, I will install new spouts (no cv) and inline checks on each lateral, and then again monitor and record sap production. When this study is completed then we can see which is a better, more cost effective alternative in protecting tap hole longevity and overall sap production.

Happy Sugaring everyone!!

[DrTimPerkins]

The operational range is between 1 and 27" of vacuum and have a cracking pressure of only 0.5 psi.

Regardless of construction, you indicated that they have a "cracking pressure of only 0.5 psi" (1" Hg). That "force" has to come from somewhere. Depending on the design, you're either losing it on the vacuum side or the tree side. In the first case you lose vacuum and potential sap yield. The other way means that the valve doesn't respond until there is a 1" Hg difference behind the valve on the tree side. That will only happen when enough sap has moved backward to cause a 1" Hg differential.


Next year I will install on one woods just check valve spouts and monitor and record sap production. In another woods with same slope, soil conditions, and tree age, I will install new spouts (no cv) and inline checks on each lateral, and then again monitor and record sap production. When this study is completed then we can see which is a better, more cost effective alternative in protecting tap hole longevity and overall sap production.

At that point you will have a sample size of 2 with a 1 degree of freedom, which statistically means you might as well be comparing apples and black bears (they're the same right....both are living organisms, both reside in woods...OR...they're different, one is a fruit one is an animal, one you eat the other eats you...with a sample size of 2 you can get any result you want). In reality you'll know only slightly more than you knew the year before. Tree age isn't nearly as important as tree size and prior tapping history.

If you wish to do a real experimental test with adequate replication (sample size way bigger than 2) that has the potential to give you meaningful results I'd be happy to assist with the design, but you probably wouldn't like the way you'd have to do it in order to draw firm conclusions from the study.

[dbeitz1891]

I'd love some help, my sample size would be much larger than 2. Woods "A" would have about 1,200 taps and woods "B" would have a little over 500. Laterals average nearly the same in length, number of taps per lateral and slope. Both woods have 3 year old 3/16 lines and both woods have been tapped for 3 years.

Back to the check valve, yes if it closes, it does require pressure or vacuum to reopen it but once it is open it remains open so it is not a continuous loss. Wouldn't the vacuum loss from opening it just be rebuilt once it is open?

[mellondome]

If you are using 5/16... you can try using a checkvalve tap and stick it inline @ the bottom of the lateral. Just make sure it is pointing the right direction

[Alex Davies]

If you are using 5/16... you can try using a checkvalve tap and stick it inline @ the bottom of the lateral. Just make sure it is pointing the right direction

Hmmmm... Got me intrigued. What would you do? stick the 5/16th line over the tap side of the spout and put on a small hose clamp to keep it tight?

The 90% abrupt change in direction here might slow down sap flow though? what do you think?

I run 3/16th laterals, but I splice them into 5/16 about 2' before the mainline because I only have 5/16th mainline manifolds. In theory, I could install here.

[DrTimPerkins]

I'd love some help, my sample size would be much larger than 2.

Unfortunately that isn't the way statistics works. Sample size refers more to the number of measurements you have per treatment than to the number of taps you have on any one treatment. So you could have 10 taps or 10,000 taps on a line, but if it all flows into one tank where you do your measurement, your sample size is 1.

To make it a reasonable sample size, you'd want at least 10 lines with 10 different measurements (tank levels) for each treatment (you have two treatments, regular CV and inline CV), so you'd need 20 tanks. That is called "replication", and it gives you the ability to get some estimate of variability in your experiment. That way you can tell whether any difference you observe is real or not (or more precisely, how likely it is that you are wrong if you determine your treatments are different). Replication is a critical component of any experiment. This design also allows you to detect outliers...spurious measurements that occurred for some reason...maybe one tank had a leak, or one mainline failed. It gives you some ability to understand that. Without replication, you have no way of knowing if something weird happened that affected one sample or another. With a sample size of only 2, you can never know for certain what factors affected your results. Maybe it was your treatment (normal CV or inline CV), but maybe it was something completely unrelated (you hit stained wood in 5% of your trees in one treatment and only 1% in the other). You need replication to know whether your results are truly "real" effects.

I don't mean to downplay producer experience here, but there is a big difference between putting some spouts in one area and different spouts in another for one season and making important decisions based on that. If you did it for 10 years and flip-flopped treatments in the two areas you have replication. If you have 10 different producers who do the same experiment with the same treatments, then you have replication. Or you can do 10 samples of each treatment yourself and achieve replication. Key point is....you need replication, and secondly, with maple production, you need multiple years to encompass natural variability in seasonal conditions. This is especially true with sanitation effects. Some years sanitation is incredibly important, other years it is somewhat less so.


Back to the check valve, yes if it closes, it does require pressure or vacuum to reopen it but once it is open it remains open so it is not a continuous loss. Wouldn't the vacuum loss from opening it just be rebuilt once it is open?

Diaphragm check-valves move in response to differences in pressure. They're like spring-hinged doors. It takes force to either open or to close them (depends upon whether they are what is termed "normally open" or "normally closed"). If they are normally-closed, it requires some pressure to "crack" them open and to keep them open. Once the pressure is gone, they will close again. Like the spring-hinged door though, if you don't use some force to keep them open, they're going to close again.

[DrTimPerkins]

If you are using 5/16... you can try using a checkvalve tap and stick it inline @ the bottom of the lateral. Just make sure it is pointing the right direction

Can't say that I endorse this approach, but it does seem to be better than using a standard check-valve (diaphragm or spring-loaded type). Keep in mind, this will protect that line as a whole from changes in vacuum (backflow) from the mainline, but won't necessarily protect against backflow within the line due to leaks that occur in that lateral line. The analogy would be something like getting an insurance policy with minimal coverage for catastrophic events versus getting a better insurance policy that protects against a wider variety of events. People are comfortable with different levels of protection.

[Haynes Forest Products]

Dang it Doc Having a 14 and 17 year old boys at home the word REPLICATION has become my new Buzz word. I was so proud when they would take out the trash or turn the lights off after leaving a room 2 time in a row. I thought for sure it was now a new habit that would propel them into adulthood and then YUP the REPLICATION came crashing down on me.

[DrTimPerkins]

Nice to have you back Haynes! :D