3/16 and Check Valve Taps on new drops

[heathrunmaple]

I'm trying to figure out the right answer to the following question. Are check valve taps more effective with 3/16 on new drops? As I understand it the back flow of sap in 3/16 is much greater than in 5/16. Greater than 10 feet vs. less than 3 as I remember. I've read that with 5/16 you don't need to use the check valve taps when replacing drops but I've never seen anything on 3/16. It would just seem to make sense to me that if the sap backflows more in 3/16 then the check valve might be more critical but I don't want to spend the extra money if I don't have to.

I've also heard some people claim that if you use a 5/16 drop on a 3/16 lateral you don't need to use check valve taps which makes no sense to me as I would think it would still back flow the 30" up the 5/16 to the tap hole. Any insight into either would be appreciated. Thanks.

Chris
Heath Run Maple Products
Ulysses PA
3000 taps
A&A 3x12 Raised Flu

[DrTimPerkins]

With new drops of any type, CV spouts (or CV adapters) will not provide much added benefit in Yr 1. Starting in Yr 2 and beyond, CV spouts will provide additional sap beyond not cleaning and beyond using a new (non-CV) spout. This is true whether you're using 3/16" or 5/16" tubing. Backflow can be more serious in 3/16" tubing however as you point out, but the number and extent of extreme backflow in maple tubing tends to be fairly low, so how much protection do you want? It comes down to protecting against the more common issues to the degree that makes economic sense. In that regard, replacement of the ENTIRE 3/16" or 5/16" lateral line/dropline system every year provides the highest sap yield but doesn't make sense economically. The gain is not worth the cost.

The caveat with CV on 3/16" tubing is that they don't totally solve the problem. In 5/16" tubing, CV spouts provide protection against microbial "taphole drying" issues. 3/16" tubing suffers from the same problem, but also has a second problem of clogging at fittings. CV spouts aren't designed to address that issue -- it must be dealt with in another way, either via using some type of tubing sanitization or by cutting out and replacing all fittings (tees and unions) from the system about every three years.

[heathrunmaple]

Thank you for the answer. That all makes sense to me from what I have read and understand but you hear so many things that it’s nice to confirm your on the right page.

Chris
Heath Run Maple Products
Ulysses PA
3000 taps
A&A 3x12 raised flue

[markcasper]

I advise NOT to use 3/16" Leader stubbies with checkvalves! Absolute garbage! A complete failure on Leader's part! The lines fill up when it freezes all the way to the drops and the stubbies then pop off. When it happens night, after night, after night, you just want to pull your hair out. I have never had much of an issue with the standard 5/16" stubbies and spouts doing this. The 3/16" Leader stubby system is an absolute piss poor design and a complete failure that they are still trying to sell. Note: I am switching all of mine out for 3/16" to 5/16" CDL drops.