3000-series Phillips 3-Way Valves

The 3000N (3/4") and 3000AN (1-1/4") Automatic 3-Way valves are configured with three external ports. The high pressure port (marked "HP") is the inlet for pressurized gas. The low pressure port (marked "LP") is the vent port. The center "common" port is open to either the HP or LP port, depending on the position of the internal pistons, as described below.

The 3-Way valves are typically used on gas-pumped liquid transfer or recirculating systems. The valve's common port is connected to the top of the pumper drum (dump trap). The LP port is connected to the suction accumulator, above the level of the liquid but below the suction connection on the accumulator. High pressure gas is fed to the HP port.

With the 3-Way valve connected as described above and the solenoid de-energized, the pathway between the common and LP (vent) ports is held open. This is accomplished by high pressure gas and an internal spring which hold the smaller (HP) piston closed against the HP seat. The LP port is open. This "vent" position allows the pumper drum to vent to the suction accumulator while it fills with liquid.

When the solenoid is energized, high pressure gas is directed internally to the space above the larger (LP) piston. This causes the pistons to move in unison, closing the LP seat and the path between the LP and common ports while simultaneously opening the HP seat and the path between the HP and common ports. This is the 'high pressure" position. The high pressure gas, now flowing into the pumper drum through the common port, can push the liquid to another location in the system. Typically, the high pressure gas should be regulated to 10 to 20 psi above the liquid destination pressure. This may need to be increased for long pipe distances. However, unnecessarily high pressure can lead to premature valve wear.

The 3000N Series valves incorporate a manual opening stem below the solenoid. When this stem is screwed in completely, the valve will automatically switch from the vent to the high pressure position when the solenoid coil is energized. Opening the stem 1/2-turn will manually cause the valve to switch from vent to high pressure.