pipe sizing for a preheater

[CrossBroMaple]

any ideas or suggestions for pipe sizing for a pre heater in a 6 foot back Pan. I'm thinking 1 inch

[village idiot]

According to the Proctor UVM paper (http://www.uvm.edu/~uvmaple/sappreheaters.pdf), 20 feet of 3/4" should be fine.

It's listed on Table 4 (the last one in the paper)

[BreezyHill]

I would go with the one inch to get as much heat in the sap as possible.

I use a stainless 1.5" that is in steam for a distance of 11' of a 2x4 flue pan on a 2x6. The sap enters in at the low thirties and hits the float box at 180+ when the rig is running. Previously we ran 20' of 1.5" copper with the same results. Switched to stainless when the copper pitted and had a pin hole leak. Stainless is easier to clean and no soldier or brazing needed. Easy to clean also.

3/4 will give you the flow you need as long as it doesn't steam, where 1" gives more surface area and a n area for sap to flow under the steam if you get the system to hot. This is why our original system had the 1.5" copper. We steamed the 1" and nearly burned the flue pan; but our preheated forces the steam to flow along the pipe for 11' before exiting the system.

9358

This is a pic of my system during the remodeling. Next season it will have plexi on the front for tours to see the steam at work.

Good Luck!