I agree. It sounds like you don't have a needle valve after the membrane on the concentrate side only. Never put any restriction on the permeate side of the membrane. You should be able to generate all the pressure you need using a needle valve with the existing feed pump. If you can't generate pressure with the needle valve then something else is probably wrong, such as damaged o-rings, damaged membrane or some issue with the plumbing. The 100 psi is not meant as a maximum operating pressure...it's just used as a basis for sizing. You will need to run 200-250 psi on cold sap to get good performance.
Last edited by bowhunter; 03-30-2019 at 07:05 AM.
Leader 1/2 pint - Kawasaki Mule - Smoky Lake Filter Bottler
24 GPH RO, 2 1/2 x 40 NF3 (NF270), 140 GPH (Brass with no relief valve ) ProCon pump
2013 - 44 taps - 16 gallons syrup, 2014 - 109 taps - 26 gallons syrup
2015 - 71 taps - 13.5 gallons syrup, 2016 - 125 taps - 24.25 gallons syrup
2017 - 129 taps - 17.5 gallons syrup, 2018 - 128 taps- 18 gallons syrup
2019 -130 taps - 18.5 gallons syrup, 2020 ~125 taps-19.75 gallons syrup