Intake Piping System
The pump is best piped into the intake system using clear, flexible but crush resistant reinforced PVC hose with a minimum ¾” diameter. If you choose to hard plumb it make sure no high stresses are imparted on the pump manifolds. Note the arrows on top of the pump manifolds. These show the flow of the water internally. I find it best to use a see- through hose so you can ascertain water flow and check for vacuum leaks. If you see bubbles in the hose, you have air leaks! Almost all wells leak some air, but too much and the pump simple can’t create enough vacuum to lift the water. I’ve installed a vacuum gage in the input manifold of the pump. The pump will create between 20” and 25” of vacuum. If you find the device won’t pump then close off the suction line where it enters the pump. Start the pump. The gage should read over 20”. This will tell you that the pump is operating correctly. If you have that, open the suction line to the well. Start the pump, and if you’re still not pumping water and you’re reading less than 20” after a minute or so then you have too much air entering the line somewhere preventing proper vacuum from forming. Remember, even if you have a perfect well and suction line it will take the pump some time to evacuate the air from the line. As more and more air is evacuated in the suction line the higher the vacuum gage should climb. It will continually climb as the water comes up to fill the suction line. IF THE VACUUM DOESN’T CLIMB, IT’S NOT THE PUMP THAT’S THE PROBLEM!!! Fix your leaks. Install the pump as close to ground level as possible. The less distance the pump has to lift the better it will pump. If you have a 15’ deep well and you have the pump 5’ above ground then for all intents and purposes you have a 20’ deep well. The pump’s intake valves act as check valves, but you SHOULD install your own check valve, the best would be a foot valve at the bottom of the well. In lieu of a true foot valve, put the check valve as close to the wellhead as possible. The least effective place to install it is right before the pump intake. Think of the old straw experiment where you put the straw in the cup and then put your finger on the straw opening. Pull the straw out, and almost magically the water will stay up in the straw. It seems its vacuum that’s holding the water in the straw, but rather its atmospheric pressure PUSHING the water up into the straw. Vacuum is really just lack of pressure. When you cap the top of the straw you block off the pressure at the top of the water column, leaving the pressure at the bottom of the straw to push up on the water. As we all know, water is more viscous (thicker) than air. Air will leak into a less than perfect seal easier than water will seep out of the leak. Therefore, if you depend on vacuum holding the water column in the suction line to the pump, you’ll have less luck than just blocking the water from coming out the bottom by using a foot valve. Water is thicker than air. The thicker the substance, the fewer the leaks you’ll have. See the image here of a foot valve. Many pump problems result from a suction line that is too small in diameter, or too long. Suction piping should be as follows to provide a smooth transition of fluid flow and result in reduced piping friction losses:
-Be short and direct -Be 1 to 2 sizes larger than pump suction connection. Avoid possible vapor pockets. -Contain a minimum number of turns. Accomplish necessary turns with a long radius elbows or laterals.
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