We use a Leader WSE 2X6. We used to batch boil...hit syrup (or near syrup) and draw off through a cone filter. Then we would finish it on propane on the side using a thermometer and hydrometer. Then we filtered again through cone filters.
A few years back we picked up a filter press. We did the same as above and then filter pressed at the end of the season when bottling.
Now we draw off consistently. The first year we used cone filters. Last year it went straight into a 5 gallon drum without a filter. Then everything was run through a filter press at the end of the year. I think this year we will likely use a smaller quantity of cone filters, just to get the majority of the stuff filtered.
With the constant draw we usually can maintain a pencil sized flow of sap with a very few temperature swings. We reduce the draw off when re-fueling and sometimes have to open it a little more to catch up. We also have a RO and concentrate to about 7-8%.
Mike
Tapping since 1985 (four generations back to early to mid 1900s). 200-250 taps on buckets and then tubing in the mid 90s. 2013- 275 taps w/sap puller 25 gal. 2014-295 taps w/sap puller 55 ga. (re-tapped to vacuum theory) 2015-330 taps full vac. 65 gal, 2016-400 taps 105 gal, 2017-400 taps 95 gal. 2018-additional 800' mainline and maybe 400 new taps for a total near 800 taps. 2x6 Leader WSE (last year on it) supported by a 250 gph RO.