Low-Temperature Valves

Low-temperature pneumatic valves are used in compressed air systems where ambient or installation temperatures can fall to -50 °C. Selection is relevant for cold rooms, outdoor automation, machinery operating in cold climates, and industrial installations where standard elastomers, lubricants, or internal mechanical components may impair switching behavior and sealing performance.

This category includes Hafner valves for panel mounting, manual lever and push-pull valves, pneumatically actuated valves, solenoid valves, NAMUR valves, and NAMUR flow controls. Available functions include 3/2, 5/2, and 5/3 configurations, with normally closed or normally open logic, single or double pilot, single or double solenoid, spring return, air spring return, bistable operation, and centre positions such as centre closed, centre exhausted, or centre pressurized.

Typical technical data include an operating temperature range of -50 to +50 °C, port sizes M5, G 1/8, and G 1/4, flow rates from 40 to 1250 l/min depending on series, and operating pressure ranges of 0-10 bar, 1-10 bar, 2-10 bar, or 3-10 bar. Solenoid-operated versions are specified with 3 W / 5 VA coil consumption and manual override, which is useful during commissioning, fault finding, and functional testing in the field.

During installation, the quality and dryness of the compressed air should be verified, including dew point in relation to minimum ambient temperature, pilot pressure availability, exhaust routing, correct port assignment, and electrical protection of the coils. Moisture, condensate, or frozen particulate contamination in the circuit can result in delayed shifting, spool sticking, seat leakage, or incomplete actuator return. Valve selection should therefore consider low-temperature seal materials, lubricant suitability, pilot supply conditions, and maintenance access for inspection of leakage and switching response.