Well Terminology (Flow Rate VS Water Pressure)

[Flipperman2a2w]

I have a few questions about the terminology used, when it comes to well yield:

Can anyone explain the correlation between flow rate and water pressure? From what I understand, flow rate is the well’s ability to replenish water, and pressure is what pushes that water through the plumbing. People seem to interchange flow rate and water pressure when they’re talking about issues of water supply in their homes, though. Assuming your pressure tank is good, you should always have as much water pressure as you need in the house, right? If there isn’t enough water coming out of the tap, though, that has everything to do with the flow rate, right?

I’ve also read that the FLOW RATE is the crucial factor when it comes to LIFTING the sand in my iron filter for regular backwash cleaning, but it seems like the WATER PRESSURE would be the determining factor when it comes to the power of LIFTING the heavy filter sand?

Hypothetically, if my well gets 10GPM, but I have a 5GPM pump, I’ll never get more flow in the house than 5GPM, right? If my iron filter requires 8GPM to backwash, I won’t be able to properly backwash that filter?

 

[Valveman]

As far as the pump is concerned, flow and pressure are inversely related. The lower the pressure, the more flow the pump will deliver. The higher the pressure, the less flow the pump will deliver. 5 GPM is the middle of the flow range for a 5 GPM pump. If the pressure is low enough, a 5 GPM pump will produce 8 GPM. You need to look at a pump curve. Not a chart, but a real curve. It will make more sense to you that way.

 

[Sponsor]

 

[LLigetfa]

Hypothetically, if my well gets 10GPM, but I have a 5GPM pump, I’ll never get more flow in the house than 5GPM, right? If my iron filter requires 8GPM to backwash, I won’t be able to properly backwash that filter?

Valveman said it well. How much the pump produces at what pressure depends on variables not known. How high the pump needs to lift will affect the GPM. Also, if you have a micronizer, depending on how much bypass is allowed, it too will limit GPM. You can plot the curve on your pump by measuring the GPM at the draincock of your tank at various pressures.

Before I replaced my pump and developed my well, I was not getting enough GPM to effectively backwash my iron filter.