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Starting Member


Thursday, September 13th 2018, 10:32am

Friction in reverse. Small pipe to large question

I understand the concept of friction when going from a larger pipe diameter to small. However, what happens in reverse?

For example, I have a well pump that has a 1 inch output and I have 1 1/4 sprinkler lines coming of that 1 inch pipe.

Since the well pump has 1 inch output does that mean i will never get to use the extra friction room that a 1 1/4 pipe gives over a 1 inch pipe?

Basically it goes: suctions up the well water via the pump at 1 1/4 then goes through the pump and discharges out of the pump orriface at 1 inch. It gets imediatley converted to a 1 1/4 pvc going to all the heads

Thanks all


Supreme Member

Posts: 5,331

Location: Metro NYC


Friday, September 14th 2018, 12:50am

Pump suction inputs are often larger than the outputs, since a pump might be lifting water through the suction line, where friction losses could actually stop the pump from working. Lifting water is more complicated than pushing water.

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