Thoughts and experiences with check valve spouts

[madmapler]

I've been using cv spouts starting with the 2nd year of drops. Although I understand and believe the theory behind them, I've heard it said several times that if you run vac. 24/7 or until everything freezes solid, their use is basically pointless which bears some merit IMO. I have to admit I'm also a little disappointed to see how many are not functioning at the end of the season whether they be plugged with debris (you don't always get a clean hole especially with guys tapping for you) or simply not sealing closed when you try to suck them shut. I expect opinions will lean in favor of them but would like any ones honest thoughts or experiences. Thanks.

[nymapleguy607]

I have used them in the past but I cant justify the added cost, I do use the seasonal non check valve spouts and I have had good luck with them.

[Brian]

I think they are great if you have a manual releaser,other than that I can't justify them eather.

[PCFarms]

We have decided to try them out this year - we have the health spouts and replace annually. Ill let you know our experience!
See the data below - The clear winner is spout replacement, once you do that, CV spout had the best result. The chart compares what is done with the spile and then the dropline. Interesting that a new CV spout plus used drop is better than new spout and new drop.

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[PCFarms]

Here is the original report, click on "2014 15 Maple Tubing Research Report"

http://blogs.cornell.edu/cornellmaple/downloadable-publications/

[DrTimPerkins]

See the data below - The clear winner is spout replacement, once you do that, CV spout had the best result. The chart compares what is done with the spile and then the dropline. Interesting that a new CV spout plus used drop is better than new spout and new drop.

My first comment is where did you get this graph? Perhaps I posted it earlier.

Other than that, I believe you need to look more closely. Spout replacement is NOT the clear winner. It is rather important to note that what this figure shows is the net profits (which is gross profit from sap yield for certain sanitation approaches at a given sap value MINUS the cost of implementing that strategy, including cost of materials and cost of labor) for several different sanitation strategies. Sap yields alone can be misleading, as it is possible to achieve extremely high sap yields, but to expend so much $ doing it that the net profit is poorer than a strategy that produces less sap but is cheaper. What you see is that the cleaning strategies (those bars in yellow) as a group (class) produce lower outcomes (in terms of net profit) than replacement strategies (those bars in green) and about the same as the blue bars (tubing cleaning + spout replacement strategies).

These are averages of trials done for two separate seasons at both UVM Proctor Maple Research Center (Dr. Tim Perkins & Dr. Abby van den Berg) and at Arnot Forest (Steve Childs, Cornell Maple Program). It was a study funded by NESARE. Steve, Abby and I have presented the results a few times, but the final report is not yet complete. It is also important to note that these studies were done with VACUUM.

What the figure shows is that spout replacement, use of CV, and drop replacement almost always produce the highest net profits for any type of sanitation strategy. The highest net profits are gained through the use of CV, while spout replacement alone or dropline replacement (including a new spout) tend to achieve about the same result, but slightly lower (in terms of net profit) than use of CV spouts or adapters. This does NOT mean that CV adapters produce the highest sap yields. On average they tend to produce slightly less than a new drop does, however the high cost of materials plus the cost of labor to make and deploy new drops each year results in a lower net profit.

One aspect that isn't well represented on this particular figure is that CONTACT time is critical in achieving any reasonable level of sanitation when using chemical sanitizers (bleach, isopropyl alcohol -- which is NOT legal in the U.S.A., hydrogen peroxide, water). Most of these sanitizers require several minutes of contact with the material being cleaned (the spout and/or drop) to be effective. Simply sucking in a small amount of solution with the vacuum on will not result in adequate microbial kill efficacy -- the solution just isn't there long enough to do much. It might help a small amount, but is not really that good in terms of increasing yields (and thus increasing net profits). The more effective way is to either flood the system with sanitizer (which uses more sanitizer and thus ups the cost), or to remove the drops and bring them in to submerge them in sanitizer (which is very time consuming).

The final report, hopefully including a spreadsheet tool to allow producers to estimate the effects in their own operations, should be out within the next six months.

[madmapler]

When I look at the graphs on page 4 entitled "Total sap per tap" and the graph next to it, it actually shows the regular spout out performed the CV slightly in total sap per tap. If this was the case then the cost of the CV spout in relation to a regular spout would have put the CV spout at a serious disadvantage. If I'm misinterpreting this then I want to know.

[DrTimPerkins]

Ok. I see what you are talking about.

The graph posted earlier is the overall averages from ALL years at all sites. The figure you are talking about is ONE site for ONE year I think, with some extra stuff tossed in. Yes, new spouts on old drops did uncharacteristically well in that one instance, and caused us all to scratch our heads a bit about it. This is a great example of why it is important that we have replication and do studies over multiple years. In all other sites and years (and in multiple previous studies), new spouts didn't do nearly that well.

Since a new spout costs $0.15 and a new CV adapter (what Steve used) is $0.35, and the cost to implement them is the same, the new spout would beat the CV by $0.20 for that case. Overall though, for all studies over all years, the CV came out ahead in terms of highest net profit achieved per tap.