Constant Pressure Systems / Variable Frequency Drives

Constant pressure systems are similar to conventional systems in that they require a pump, a pressure tank and a pressure switch or sensor.  The pressure sensor monitors a system’s pressure and sends a signal to the control panel for the pump. A controller then signals the pump to perform at a rate required to maintain an optimized pressure and volume. The pressure setting may be adjusted at either the pressure sensor or motor controller depending on the system.
Constant Pressure System
Pressure Tank
A pressure tank in a constant pressure system is typically much smaller than in a conventional system.  In a constant pressure system, the tank stores very little water acting primarily as a buffer to prevent pressure fluctuations.
Back Camera
Pumps used in a constant pressure system are basically the same as those used in a conventional submersible system.  The difference is the motor attached to the pump runs at variable speeds depending on water demand.  The motor speed is controlled by a variable frequency drive controller.  Depending on the specific system, the motor could be a single or three phase unit.


Benefits of a Constant Pressure System

  • System maintains steady pressure instead of cycling with a 20 pound differential.
  • Ideal for multiple uses, including sprinkler and drip irrigation systems.
  • Requires a much smaller pressure tank, saving space in what typically is a confined mechanical room, pump house or pit.
  • Soft starts and stops equating to less wear on the pump and motor. On units operating a three phase motor, wire size can be smaller which means less cost in applications when a pump depth is deep.