4-Way Solenoid Valves
4-way solenoid valves (typically 4/2 or 5/2 with four working ports plus exhaust) provide pressure to one side of a double-acting cylinder or actuator while exhausting the other, then reverse both connections to drive it back. This makes them the standard directional-control element for double-acting pneumatic actuators on automated ball and butterfly valves, and for reciprocating cylinders in machinery. A single-coil 5/2 valve toggles between two positions; a double-coil (bistable) version latches in the last commanded position; 5/3 variants add a centre position (closed, exhausted or pressured) for mid-stroke holding.
Function is defined by the position/port count and centre condition. The construction is direct-acting (small pilot duty, zero differential) or, more commonly for actuator service, internally pilot-operated, where the coil opens a pilot that uses supply air to shift the main spool — giving high flow from a small coil. NAMUR-mount 5/2 valves bolt directly to a double-acting actuator's NAMUR interface, porting both cylinder chambers through the mounting face without external tubing; sub-base and manifold mounting suit machine builds.
Materials are aluminium, brass or SS316 bodies with NBR, FKM/Viton, EPDM or PTFE seals selected for the media (usually clean, dry, lubricated or non-lubricated instrument air) and temperature. Coils are 24 VDC or 110/230 VAC in IP65/IP67 or ATEX/IECEx Ex d/Ex m enclosures for hazardous areas, with manual override for commissioning.
Because actuation is electrical, configuration centres on coil voltage, function (5/2 single/double-coil, 5/3 centre condition), direct-acting vs pilot-operated, NAMUR vs sub-base mounting, and enclosure/Ex rating rather than mechanical actuators — along with the spool's fail/last position for the double-acting actuator. Himalay's MSME partners manufacture 4-way solenoid valves with electrical and leak testing, IP/ATEX-IECEx documentation where specified, material traceability, and PED-CE (EU), SABER (Saudi Arabia), and NACE MR0175 (sour service) coordinated as part of the standard order flow.
