G+_Roy Z Posted January 20, 2017 Share Posted January 20, 2017 KH279 plant watering system: If the valve they were using actually needed 3 psi to open, it would not work on a 5 gallon bucket. One foot of water is only about 0.43 psi. A full bucket would provide less than 1psi. Surprised no one did the math! Link to comment Share on other sites More sharing options...
G+_Jon Papai Posted January 21, 2017 Share Posted January 21, 2017 Also, how about that 3/4 inch hole. Maybe 1 3/4 inches? Link to comment Share on other sites More sharing options...
G+_Fr. Robert Ballecer, SJ Posted January 21, 2017 Share Posted January 21, 2017 It works....So... You know... Link to comment Share on other sites More sharing options...
G+_Roy Z Posted January 21, 2017 Author Share Posted January 21, 2017 Not sure how valves are rated Found this in an ASCO PDF - "Minimum Operating Pressure Differential: The minimum operating pressure differential is that which is required to open the valve and keep it open. For 2-way valves with floating piston or diaphragm, the valve will start to close below the minimum differential pressure." Thus appears the valve is partially open and never fully open? Link to comment Share on other sites More sharing options...
G+_Peter Harpur Posted January 22, 2017 Share Posted January 22, 2017 Cool project Padre. What if you were to connect the bucket to some tubing before the solenoid valve? This would allow the bucket to be elevated above the valve to create whatever head pressure required. This might help solve the problem of the "unusable bottom third" of the bucket. Just a thought. This youtube does a great job of explaining hydrostatics: Link to comment Share on other sites More sharing options...
G+_David Wiggins Posted January 23, 2017 Share Posted January 23, 2017 I was watching the episode on the projector at work during lunch, and one of the engineering instructors suggested a tall, 6 in (I believe) PVC with the same volume to assist in any pressure difficulties. Granted, this breaks the whole 'things you have lying around' part of the build. She did these kinds of builds to assist in testing water around power plants in the 80's and 90's. Link to comment Share on other sites More sharing options...
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