water won't draw from pond

[jhs]

I drilled a 2" hole in my basement, dug an 80' foot trench to a pond abutting our property, and connected 80' of 2" inch pvc pipe, with minimal joints, to a 1 hp jet pump in basement, with a foot valve at the end of the pvc pipe, which is in the pond. I prime the pvc pipe, but when I turn The pump on, no water comes through the pipe. Elevation over the 80 feet is minimal, maximum 2 feet. All joints are air tight, no leaks. Should I put a check valve befor the foot valve?

 

[Bob NH]

It is very hard to prime a long suction pipe.

It is even harder if the suction pipe is not RISING slightly, with no high spots or humps, from the suction end to the pump.

If there are any humps (high point followed by a lower point) between the inlet and the pump, then air will be trapped at the high point and the pump will not prime.

The only way to fix it is to get all of the air out. If you can, try applying a wet/dry shop vacuum, through a valve, to the line at the pump end until you get a good flow of water. Then turn off the valve to keep from losing the prime.

Then start the pump.

If you have a hump and you know where it is, you can fix it. One way is to run the pipe on a rising grade. Another way is to put a tee in the line at the high spot, with a ball valve, so you can prime the pump and vent the air at the high spot. I would resort to that only if you can't get it to prime with the shop-vac.

 

[Sponsor]

 

[Speedbump]

If you put all the water in the pump that it will take, then don't tighten the priming plug which must be on top of the pump. Leave it very loose to let the air bubbles out. You said this is a jet pump and they are all self priming. Some better than others though. It may take several more fillings with water before it catches, but it will eventually. Unless of course the impeller is broken or plugged with debris.

bob...

 

[jhs]

Thank's guy's. Irrigation system, and pump shut down for the fall, and coming winter. I'll let you know how I make out in the spring.