Series LFPV20CB is a direct sensed direct acting, diaphragm actuated Pressure Relief pilot. It is normally held closed by the force of the adjustable spring setting above the diaphragm. It modulates toward an open position when control pressure, exerting force below the diaphragm, exceeds the spring setpoint, and modulates toward a closed position when thecontrol pressure falls below the spring setpoint. The LFPV20CB senses upstream pressure through a tapped inlet port. The large diaphragm-to-seat ratio allows it to open and close within close pressure tolerances. Turning the adjustment screw clockwise raises the control setpoint. Turning the adjustment screw counterclockwise lowers the control setpoint.