tedln wrote:I have a lot more experience working with industrial pumps where you have "head" or pressure on the low pressure side of the pump. When you don't have water pressure on the low pressure side of the pump, the pump must be able to suck or create a vacuum to pull the water to it. The longer the line is on the inlet side and the lower in elevation the source is, the more difficult it is to actually pump. I am really curious what kind of pump LnG is using to pull water from the lake after the elevation drops ten feet. Centrifugal or reciprocating? Do you have to prime the pump with water in order to establish suction?
Ted, I do have to prime the pump each spring to get my irrigation going, and it takes awhile to get the air out of the line. I do not know enough about it to know centrifugal or reciprocating. It is one LONG pipe out into the water. I do not move it back or forth based on water level. Each winter I take off the intake valve and let it drain. So much of the pipe is exposed on the shore that it would freeze on me otherwise.
Before this pump I had another type that might be like you describe. I still had to prime it each spring, but it was two pipes running out into the water, one smaller than the other. I understood it to help with the intake at the valve, but I know little about pumps and pipes.
My lake neighbor has the same setup I have now, with the single pipe. But he is back in a slough and has to run his pipe a farther distance to stay in water. Back in 2007 we had a severe drought and the water level dropped almost 17 feet in July. So to water his yard he had to extend his pipe by almost 50 feet. So I know this method will pull water a LONG way.
Does that answer your question?