Series-265

Supported Applications

The Dwyer Series 265 PRECISOR® II positioners are designed for the rotary operation of pneumatic valve actuators, specifically controlling ball and butterfly valves. The series supports both single-acting and double-acting actuator configurations using either an analog electrical controller or a pneumatic control system.

These devices modulate valve positions based on input signals from industrial automation systems:

• Pneumatic Control (Series 265NR): Accepts output signals of 3 to 15 psig (0.2 to 1 bar) or split ranges.
• Electro-Pneumatic Control (Series 265ER): Accepts analog electrical output signals of 4-20 mA DC or split ranges.

Operating Conditions & Performance

The Series 265 positioners operate within a supply air pressure range of 20 to 101 psig (1.4 to 7.0 bar). The devices feature an IP66 enclosure rating and are constructed from aluminum diecasting or available in 316 SS for harsh environments.

Performance specifications include:

• Linearity: ±2% FS
• Hysteresis: 1% FS
• Sensitivity and Repeatability: ±0.5% FS
• Air Consumption: 0.10 SCFM (3 LPM) at 20 psig (1.4 bar) supply
• Flow Capacity: 28 SCFM (80 LPM) at 20 psig (1.4 bar) supply

Ambient temperature limits vary by model configuration: -4 to 158°F (-20 to 70°C) for standard and stainless steel versions, and 4 to 140°F (-20 to 60°C) for the FM-rated version. The positioners provide a stroke of 0 to 90°.

Configuration Options

The series offers configurable options across input types, lever configurations, and enclosure materials:

• Housing Materials: Aluminum diecasting or 316 SS (stainless steel).
• Lever Types: NAMUR standard mounting bracket included.
• Action Selection: Field-selectable cam design supports Direct Action, Reverse Action, and Split Ranges.
• Connections:
• Air Supply: 1/4" NPT
• Gage Connection: 1/8" NPT
• Electrical (265ER only): Screw terminal with 1/2" NPT female conduit connection.
• Certifications: CE marking is available for the Series 265ER electro-pneumatic models.

Key Product Differences

The series distinguishes between pneumatic and electro-pneumatic operation through two primary model families, with specific dimensional differences based on input type and material:

• Series 265NR (Pneumatic): Designed for 3 to 15 psig inputs. Dimensions are approximately 7-1/4" [184.00] wide x 6-1/2" [165.51] high x 3-1/4" [83.01] deep, weighing 3.1 lb (1.7 kg).
• Series 265ER (Electro-Pneumatic): Designed for 4-20 mA DC inputs with an input impedance of 250 ±15 Ω. Dimensions are approximately 8-25/32" [223.04] wide x 6-9/16" [166.69] high x 4-3/8" [111.13] deep, weighing 6.2 lb (2.8 kg).

Additional accessories include a stainless steel flex hose (Model A-228) and brass adaptors (Model A-332). The series includes features such as no resonance in the 5 to 200 Hz range, easy zero/span adjustment, and protection against hunting effects via output orifice options for small actuators.