What is the function of a pressure limiting valve relative to a pressure relief valve?
Pressure reducing valves limit the pressure that can pass through the valve. The valve remains open and fluid flows freely to downstream devices until the pressure in the valve reaches the pressure (adjustable) set-point. At the set-point pressure, the valve closes blocking further flow and pressure rise to the downstream devices. If there is sufficient down stream pressure loss, the PRV will re-open and allow flow to pass through the valve until the pressure returns to the valve set-point. Pressure relief valves (sometimes known as pressureregulating valves) are intended to guard against excess pressure. When a circuit builds beyond the setting of a pressure relief valve, it opens and excess fluid is returned to tank through a return line. If a relief valve is set below the pressure adjustment of a pump, the pump will kick on and off frequently. Incorrect adjustment of a pressure relief valve can cause expensive damage to your pump.
