+ Reply to Thread
Page 2 of 2 FirstFirst 12
Results 11 to 14 of 14

Thread: Pressure Switch for Small RO

  1. #11
    Join Date
    Mar 2018
    Location
    Vermont
    Posts
    51

    Default

    Pressure switch works okay, but I've found its not perfect because many times if you spring a leak, the pressure doesn't actually drop enough to shut the system down. If it's a shut off when your tank is empty that you are after, a bilge pump float mounted in the bottom of the feed tank works better - it takes a long time for the pressure in the membranes to drop so the pump is running dry for a while until the low pressure switch triggers - a float shuts off immediately. I have two switches wired in series on mine - Low pressure or empty tank will shut the system down. Build in a bypass switch so you can override the system when you start up and the pressure is under the low pressure switch or when you want to empty the lines when the tank is empty.
    Last edited by Msboucha; 10-20-2019 at 01:28 PM.
    Season Totals
    • 2019 - 24 Taps / 11.5 Gal. Syrup
    • 2018 - 24 Taps / 20 Gal. Syrup
    • 2017 - 18 Taps + 7 Taps added Mid-Season / 15 Gal. Syrup
    • 2016 - 18 Taps added Mid-Season / 5.25 Gal. Syrup
    Current Equipment
    • Off-grid solar/battery powered home-built RO and "Sugar House"
    • Homebuilt 34x17 Propane Evaporator

  2. #12
    Join Date
    Feb 2013
    Location
    Freedom, IN.
    Posts
    141

    Default

    I also had problems with residual pressure on the membranes being too high to allow the low pressure switch to open. I thought about going the float switch route, but wanted to drain the sap tank as low as possible, and a float just wouldn't allow a complete drain down. this season I'm going a different route...I've installed a normally open vacuum switch on the intake side of the RO pump. Upon testing, it looks like exactly what I needed. It closes at 1.5" of vacuum, and will open as soon as the intake pipe in the sap tank gets a gulp of air. It leaves less than a half gallon of liquid in the tank. I do have a bypass switch in the circuit, which I hold closed until vacuum closes the switch. Paid less than $20 dollars for it If I recall.

  3. #13
    Join Date
    Mar 2019
    Location
    CT
    Posts
    27

    Default

    Can you post a link to the vacuum switch you used?
    2019 - First Season with a Late Start. 10 taps on buckets, block arch and 2.5 gallons of syrup.

  4. #14
    Join Date
    Feb 2013
    Location
    Freedom, IN.
    Posts
    141

    Default

    I used this:
    https://www.powerwash.com/mtm-hydro-...r-control.html

    I made sure to mount it higher than the level of sap in the tank, so sap will never contact the membrane in the switch.

+ Reply to Thread
Page 2 of 2 FirstFirst 12

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts