Core Technical Advantages
-
Field-Proven Spool Valve: The 3720 utilizes a mechanical spool valve architecture. This design is intentionally simple to ensure high reliability, fast response times, and an exceptionally long cycle life in demanding throttling service.
-
Environmental Resilience: Engineered for survival, the 3720 uses materials designed for harsh environments. When configured with EPDM O-rings and specialized diaphragms, the unit remains fully operational in extreme low-temperature applications.
-
Industry-Specific Compliance: For sensitive industries like food and beverage, pharmaceuticals, and tobacco, the positioner can be outfitted with specialized gasket materials (Fluorocarbon or EPDM) to meet purity and chemical compatibility requirements.
-
Stable Calibration: The internal feedback and pilot mechanisms are designed to resist drift. Fluctuations in plant air supply pressure or ambient temperature swings have minimal impact on the valve’s setpoint accuracy.
-
Modular Maintenance: By removing the cover, technicians gain full access to all internal components. Its modular nature means users can easily upgrade or repair specific sections of the assembly without replacing the entire unit.
Technical Specifications
| Feature | Details |
| Input Signal | DC Current (4-20mA standard) |
| Output Action | Single-acting or Double-acting |
| Actuator Type | Rotary (Diaphragm or Piston) |
| Operating Temp | Standard or Low-Temp (with EPDM components) |
| Pilot Type | Spool Valve |
| Diagnostics | Compatible with external connectors for FlowScanner testing |
Applications and Industry Sectors
The 3720 is a workhorse positioner found in diverse process environments:
-
Petrochemical & Oil: Managing rotary valves in outdoor skids where high vibration and temperature extremes are common.
-
Food & Pharma: Throttling sanitary valves where material compatibility and washdown resistance are essential.
-
Pulp & Paper: Operating high-cycle V-ball valves for consistency control and stock flow.
-
Power Generation: Accurate positioning of dampers and cooling water rotary valves.
Xi’an Yunrui Trading Co., Ltd. Technical Support
Xi’an Yunrui Trading Co., Ltd. is a specialized supplier of original Fisher and Emerson automation solutions. We provide deep technical expertise to ensure your Fisher 3720 is correctly configured for your specific rotary actuator—including selecting the appropriate seal materials and action type (single or double-acting). Through our optimized supply chain, we deliver these high-performance positioners with a significant pricing advantage.
If you are upgrading a purely pneumatic 3710 to an electro-pneumatic 3720, or if you need to verify mounting kit compatibility for a specific third-party actuator, please contact our technical team for assistance.
