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View Full Version : Check Valves On Main Lines?



MERIDIAN MAPLES
05-06-2010, 07:47 AM
I was reading a Northern Tool catalog last night, and they had 1" and 1 1/4" stainless check valves. As I saw them I thought about the check valve adapters. Would putting check valves on your main lines do what the check valve adapters are doing? Right now I'm using the stubby spouts with just the standard insert.

DrTimPerkins
05-06-2010, 08:15 AM
I was reading a Northern Tool catalog last night, and they had 1" and 1 1/4" stainless check valves. As I saw them I thought about the check valve adapters. Would putting check valves on your main lines do what the check valve adapters are doing? Right now I'm using the stubby spouts with just the standard insert.

It would only partially do the same thing. It would mitigate against the releaser-induced backflow (small, frequent pulses of sap moving backwards caused by releaser dumps). It would not solve other problems (leaks, refreezing pulling sap from drops, etc.). So it would not really greatly reduce the amount of microbial contamination moving from the tubing/spout into the taphole. Thus the benefit of putting a CV in the mainline is fairly minimal compared to putting it as close to the taphole as you possibly can. Hence the reason the CV was put in the adapter.

Russell Lampron
05-06-2010, 06:18 PM
When a single mechanical releaser dumps the flapper to the secondary chamber is the check valve. Adding one to the mainline wouldn't do much to stop the back flow. It might also create a restriction that could freeze and cause flow problems.

DrTimPerkins
05-06-2010, 06:57 PM
When a single mechanical releaser dumps the flapper to the secondary chamber is the check valve. Adding one to the mainline wouldn't do much to stop the back flow. It might also create a restriction that could freeze and cause flow problems.

Correct, however it isn't a perfect seal. A certain amount of air is leaked into the upper chamber and creates pulses. If you are going to add a CV to your mainline (and I assume your releaser is inside a heated room), I'd put the mainline CV inside the heated room also to prevent freezing up. Either way, it won't function the same way the CV adapter does because it is only addressing one part of the problem, not the entire problem.

Russell Lampron
05-06-2010, 07:25 PM
My releaser is outside 900' away from the sugar house and heat. Freezing is a big enough headache without adding more potential problems. I didn't do 100% cv adapters this past season but plan to next year. From the back flow and freezing that I have seen the tap hole is the best place for the check valve.

collinsmapleman2012
01-27-2011, 07:41 PM
now if you had a sap sucker pump(pump with no releaser) i think this would be beneficial because when these pumps are shut off you can hear the sap rushing back, and i think that vacuum could be kept on the lines until it goes out at the other end, therefore preventing sap from going far back in the lines. just a thought