It is not influenced by pipe size, number of fittings or viscosity. Static pressure is determined solely by fluid density and the difference in height between the pressure switch and the outlet of the pipe. 12 ft above the gauge, so static head is 12 ft, which exerts 5 psi of pressure. Friction pressure results from the flow of liquid through a pipe and is present only when the pump is running. It depends on flow rate, size and length of pipe, number of fittings and fluid viscosity.
Total pressure is the combination of static and friction pressure.
This pressure is observed directly by reading the gauge on the pump discharge. When the pump is idle, the gauge shows static pressure. When the pump is operating with flow present, the gauge shows total pressure. In the example in Figure 4, total pressure is 25 psi. For run dry protection, set the low pressure switch midway between the static and total pressure.