Sump pump discharge line

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redman407

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Professional Handyman here. Have stayed away from any major plumbing and electrical for years. There has been up surge in new home construction in my area. So I've been doing sump pump installs but mostly just the discharge lines. I've installed about 60 in the last three years. This most recent discharge line we rushed to get it done because of incoming rain and storm. I use a freeze protection and discharge to daylight with 3" SDR35. That's what's used in the area northern Ontario Canada. Because the homeowner was very concerned about rodents and we were in a rush. Plus could not find a proper outlet that was small enough for rodents. I made a small dry well. Angled the outlet with a 90 to one side, capped it and drilled a dozen 1/4in holes. Filled it with river rock. Tested the pump with 3 buckets of water and water discharged with no problems. The storm never came only rain off and on for a few days. In a few days we are to go back to install proper outlet. Home owner reports the pump does not come on. Still raining off and on. No flood in basement nor does the pit fill with water. Before install discharge line, pump would cycle off and on repeatedly with the slightest bit of rain. Once I go back what should I check to ensure proper operation.? Thoughts and advice appreciated.
 
Have you restricted the flow like this before, you could have used stainless mesh and either rolled it up so it would fiit into the pipe or put it over the end and bent rtherest back and used hose clamps to secure it, I think it stopped running because it wasn't able to pump properlyi can't say why it's not filing
The way it was
 
Have you restricted the flow like this before, you could have used stainless mesh and either rolled it up so it would fiit into the pipe or put it over the end and bent rtherest back and used hose clamps to secure it, I think it stopped running because it wasn't able to pump properlyi can't say why it's not filing
The way it was
No I've never done it like this before. We used what we had available.
 
I did something like this to keep rodents out of my generator just cut s.s mesh to size and rolled it up to plug open air vent holes I think it would work with pipe as long as it's s.s it won't rot away
 
The question is, is there water flowing into the sump?

It is a little strange that the pump was cycling prior to this during a rain and now it isn't, assuming it was "always" happening. So, the first thing to check is that the pump is functioning. Check the electrical to the pump and then check that the pump operates.

I would find it very surprising that the pump has failed because the discharge was restricted. As long as the pump has some meager amount of flow, a restricted discharge will simply lower the flow rate through the pump, moving the operating point back on the pump curve. I would expect that you would have to deadhead the pump for it to fail. And the thermal reset would likely return the pump back into operation once it cooled off.
 
The question is, is there water flowing into the sump?

It is a little strange that the pump was cycling prior to this during a rain and now it isn't, assuming it was "always" happening. So, the first thing to check is that the pump is functioning. Check the electrical to the pump and then check that the pump operates.

I would find it very surprising that the pump has failed because the discharge was restricted. As long as the pump has some meager amount of flow, a restricted discharge will simply lower the flow rate through the pump, moving the operating point back on the pump curve. I would expect that you would have to deadhead the pump for it to fail. And the thermal reset would likely return the pump back into operation once it cooled off.
Thanks for this. I will confirm the pump is operational. The homeowners states that the pump would repeatedly 5 or 6 times an hour. Likely because the discharge was 5 feet away from the house and being dumped onto the lawn.


Can you Explain this further

"moving the operating point back on the pump curve"
 
Here is a typical pump/system curve.

1698683436280.png

The system curve (labeled System Characteristic on the table above) is the pressure required to produce the flow through the piping system at the listed flows. It includes the friction drop through the pipe and fittings, as well as the inlet and outlet pressures, and the elevation difference between the inlet and outlet. The higher the flow, the more pressure is required to "push" the fluid though the system. The pressure drop can be calculated if the piping system is well defined.

The pump curve (labeled Performance Curve on the table above) is what the pump is capable of producing. Let's assume a valve is in the discharge line and it is closed. The pressure the pump produces is the maximum pressure it is capable of. Let's then slowly open that valve. As flow is allowed to increase, the pressure the pump can produce decreases. Once the valve is totally open, the pump curve will meet the system curve which is the operating point for the system. Each pump has its own curve, so this is just an example.

When you added a cap at the end of the discharge pipe, that was like a closed valve until you drilled the holes in it. For every hole you drilled, that decreased the pressure required to "push" the fluid through the system, lowering the system curve, and allowing the pump to move out further on its operating curve. So, with more restrictions in the discharge line, the pump pumps less "moving the operating point back on the pump curve". With a more opened ended discharge line, there will be less restriction in the system, and the pump will move out on the pump curve pumping at a higher flow rate, but at a lower pressure. Again, where the pump curve and the system curve meet will be the operating point for the pump system.
 

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