In Line Check Valve

[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