Float box question

[mol1jb]

Hi all,

When adding a float box to a sap pan, how high should I put the outlet going from the box into the pan?

Jacob

[psparr]

It needs to be at least as low as you plan on running the pan.
Also the bottom of the float box should be below the bottom of the pan to allow the float to actually float.

[mol1jb]

Thanks for the info. And what would be a good size for the outlet?

[psparr]

Personally I would do 1" you could get away with smaller, but if you need to flood the pan quick you want a bigger opening.

[Big_Eddy]

psparr provides good information.

Make sure the bottom of your float box is at least the thickness of your float plus 1-2" BELOW your expected sap level, so the float can sink and open wide, and have a nice big opening between the float box and the pans so the float will react quickly. I have a 1" connection and I feel it's too small.

After building mine and learning it's weaknesses, I strongly believe it's better to have a float valve that is either wide open or tightly closed, rather than one that opens more or less based on evaporation. Mine is more the latter, and my float box sometimes "gets behind" my evaporation rate when things are really boiling. This results in the overall depth in the pans dropping well below my target 1" and more than one quick dump of safety sap from the OSB. On the flip side - if things slow down it will keep letting in a trickle of sap, raising the level above where I want it to be.

Redesigning it is on my to-do list.

[RollinsOrchards]

On my evaporator the float box is in two parts. The box that the float is in is hooked to the evaporator by a 2" tri-clamp fitting. When the level goes down to trigger the float then the fresh sap drops into a different compartment of the float box, which is connected to the opposite corner of the flue pan also by a 2" tri-clamp fitting. This keeps the surge from the valve opening from giving a false reading to the float.