In Line Check Valve

[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!