Overview
The Keystone F79U 065 double acting pneumatic actuator (part number 221 952 065 79U 000) is a compact, industrial-grade quarter-turn actuator engineered for high-cycle valve automation applications. This actuator delivers reliable torque output in both air-to-air and spring-return configurations, making it suitable for remote control of ball, butterfly, damper, and rotary plug valves across process control, HVAC, and fluid handling systems.
Key Features
- Double Acting Design: Air-operated in both directions for responsive control and full stroking capability
- Adjustable Travel Stops: Standard on sizes 065 through 181 for 7° undertravel and 5° overtravel adjustment
- High Torque Output: 13,444 lb.in. double acting torque at 120 psig rated supply pressure
- Quarter-Turn Operation: 90-degree rotation ideal for on/off and modulating valve control
- Mounting Flexibility: Direct mounting compatible with Keystone and Namur standard valve stems; optional adaptor plates for various bolt patterns
- Broad Accessory Support: Compatible with solenoid valves, limit switchboxes, positioners, and manual overrides
Technical Specifications
Key operational parameters for the F79U 065 actuator:
- Rated Supply Pressure: 120 psig (827 kPa)
- Maximum Supply Pressure: 150 psig (1034 kPa)
- Double Acting Torque Output @ 120 psig: 13,444 lb.in. (1,517 N·m)
- Spring End Torque @ 100 psig: 4,943 lb.in. (558 N·m) [spring-return models only]
- Operating Temperature Range: −20°F to 210°F (−30°C to 100°C) standard; optional ranges up to −40°F to 160°F available
- Stroke Time @ 90 psig (no load): Approximately 3.6 seconds (double acting)
- Body Material: Extruded aluminum, hard-anodised per BS 1474 6063
- Shaft Mounting: Keystone standard (CAF/CAG/CAH) or Namur compatible
- Air Consumption: Adjustable via speed controls, pilot valves, or quick-exhaust accessories
Typical Applications
The Keystone F79U 065 is specified for:
- HVAC damper control in large commercial buildings
- Process water and steam isolation valve automation
- Modulating control in pharmaceutical and food manufacturing
- Pneumatic ball and butterfly valve actuation in compressed air systems
- Emergency shut-off valve control requiring fail-safe operation
- Industrial blending and diversion valve applications
Compatibility & Replacements
Compatible With
- Keystone butterfly, ball, plug, and damper valves
- Namur-mounted quarter-turn valves
- Pneumatic solenoid valve systems (2/2, 3/2, 4/2, 4/3 configurations)
- Pilot-operated control systems with oversized and quick-exhaust valves
- Integral limit switchboxes and electro-pneumatic positioners
- Industrial automation networks using pneumatic control signals
Replaces / Drop-In Replacement For
- F79U-065 previous generation models
- Generic pneumatic quarter-turn actuators in the 065 size class
- Equivalent Pentair/Keystone F79U platform models
Works With
- Compressed air systems (40–150 psig operating range)
- Pneumatic solenoid valve pilot circuits
- Flow control and speed controller accessories
- Manual override gearboxes (declutchable models available)
- Position indicator and feedback systems
- ATEX, IEC, CSA, and InMetro certified control packages (verify specific configuration)
