Usually there is a pressure differential of 20 PSI. Generally, the pressure switch turns on at 40 PSI and off at 60 PSI, which with a properly sized pressure tank; you will get about a minute of pump run time, which is required in a conventional pump system.
Kellner LLC has always relied on top of the line Gould's GS series submersible pumps for use in a conventional system. We have been installing them for over 30 years. Gould's pumps are designed for residential and small municipal water supply as well as light irrigation applications. They are constructed with a cast 303 stainless steel discharge head and motor adapter, superior sand handling capability, built-in stainless steel check valve, lexon impellers, and a Centripro motor designed for continuous operation. Gould's offers many size pumps ranging from 5 GPM to several 100 GPM.
Kellner, LLC stocks a wide range of Goulds pumps that will fit almost any application so that when you run out of water, we can quickly get you back up and running.
If the jet pump sounds as thou it is not very efficient, that's because it is not. Before the submersible pump, the jet pump was better than pumping by hand, but with new technology we have come a long way with efficiently.
We at Kellner, LLC believe that although jet pumps do have a place, a submersible pump is far superior to it. Submersible pumps are quieter, more efficient, cost less to operate, easier to troubleshoot, and in many cases, would be less expensive that a jet pump to install.