Vacuum Pump Station Critique

[wmick]

I had a very similar situation yesterday. 100 taps on 3/16, 5gpm pump. No recirculation line. The vacuum would sit around 12", flow would start to come in, up to 22", sap coming in good. Then eventually there was not enough flow to sustain the vacuum and it would drop back to 12". Sap would flow backwards in the lines. Cycle repeated every 10 minutes. I swapped the 5gpm pump for a 3gpm Shurflo 4008, reasoning that the smaller pump would be better at holding a steady vacuum. Bingo, after that it held 22" steady for the rest of the day. I am thinking that my trees were not flowing well yet so the larger pump did not work well with the low flow. I want to try it again later in the season when sap is running hard to see if it makes a difference.

Dave

Thats interesting.... Thanks for the update... If you didn't have the smaller pump handy, I wonder if putting a valve on the output of the pump might work as well? Im guessing not, because air would flow through the valve much faster than liquid... Might not be able to maintain any consistency either...

Or another thought.... Rheostat speed control on the pump motor... DC motors are easy to speed control, by simply lowering the voltage... but I don't know if these pumps would take to it?

[HondoLane]

Here is a video of it today. Sap seems to be flowing better. I opened the needle valve all the way and it seems to run the best as in “pulls hard” but then it stalls, then pulls etc. I appreciate the help. I do t have any close maple friends that I can personally view setups etc so I rely a lot on the trader to help!!

https://youtu.be/j08Xny0afWk

[mainebackswoodssyrup]

That looks like it’s working OK to me.

[HondoLane]

Well... needless to say it is working. No leaks. It was just a case of sap not flowing from trees. In fact it’s working so well... last night everything froze outside but inside box and insulated recirculating lines, etc didn’t freeze. Today when pump kicked on... vacuum has shot up to and pegged my gauge trying to suck frozen exterior sap lines!!

E394311A-7202-4C8B-B33B-095FAAEAF7CA.jpg