1.5" Ball Valve Between Pans - Freezing Risk?

[snoskier16]

So I have a quick question regarding the proper use of a ball valve that connects the rear pan to the front pan. In theory, the sap should be concentrated enough that closing the valve at the end of a boil to try and conserve a gradient would work, but I'm concerned that normal overnight lows, say mid-20's, might damage the valve. Any experience or words of wisdom? I'd rather not blow out my valve, but would like to keep a gradient better between pans.

[tcross]

if you're worried about it expanding and breaking the valve you could always get some pan hole plugs and use them rather than shutting the valve. however, i've never had one break on me.

[ecolbeck]

A sweetened pan tends to get slushy rather than freeze solid. I assume you have a valve on your draw off as well? It would be subject to the same temps and I don’t think they are problematic.

[BAP]

If it’s a stainless steel ball valve, they are pretty rugged and take a lot to split open.

[raptorfan85]

If you're really worried about it you could use a gate valve. If they freeze they don't split apart like a ball valve.

[maple flats]

If you have boiled hard for at least 4 hours, the sugar will be high enough that it will not freeze enough to blow the valve.
However, before I had butterfly valves on my sap tanks, I used 2 valves, one behind the other. First I closed the valve closest to the tank, opened the second valve to drain it, then closed the then empty #2 valve and opened the #1 valve. An open ball valve will not burst if frozen, but if the ball is full of water (or sap) and it is closed, that sap is trapped, and freezing can blow the valve.

[blissville maples]

So I have a quick question regarding the proper use of a ball valve that connects the rear pan to the front pan. In theory, the sap should be concentrated enough that closing the valve at the end of a boil to try and conserve a gradient would work, but I'm concerned that normal overnight lows, say mid-20's, might damage the valve. Any experience or words of wisdom? I'd rather not blow out my valve, but would like to keep a gradient better between pans.

I wouldn't worry a bit. 4 nights of 20s with no boils in-between, that's a different story. But mid 20s for 8-10 hours is nothing especially if the evaporator has been used, since it will hold heat for a while.

[Russell Lampron]

You don't have to worry about the valve freezing at all. The sugar will keep the concentrated sap from freezing hard enough to break anything, even in temps below zero for an extended time. I've never drained mine between boils and let it sit like that for up to 3 weeks in freezing weather without a problem.

[TapTapTap]

We've had very cold days without a problem.

[MapleMark753]

Unfortunately I've had a couple of valves split, burst, whatever you want to call it. Thats after starting with 4-6 percent concentrate, then boiling a good amount of time maybe 3ish hours before shutdown time. Admittedly its only been when its gotten unexpectedly cold here, say when the forecast calls for 23 as a low, and then low and behold I wake up and its a crisp 15. Now, every time, evverryy time, its forecast 27 or lower than that I drain the pans into buckets at shutdown. Just a bit more time and work, but zero burst valves since I began doing that. I've tried to attach a pic of my two failures. I just keep the valves as a reminder to myself to do the right thing even when I'm tired at the end of the day.Valvesburst.jpg