Valves with NAMUR-Interface - Flow-regulator plate | Hafner

Hafner NAMUR Flow Control Plates

Hafner DRN flow regulators are intermediate plate-type devices designed for installation between a NAMUR valve and a pneumatic rotary actuator. They enable adjustment of process valve opening and closing speeds without the need for additional external tubing, supporting compact actuator assemblies in industrial automation.

Variants

• DRN 3 601: For 3/2 NAMUR valves, manual adjustment, DN 5, 650 l/min, 0.5–10 bar, NAMUR 1/4”.
• DRN 3 611: Same function, screwdriver adjustment for tamper resistance.
• DRN 3 128: NAMUR 1/2”, DN 8, 1500 l/min, suitable for larger single-acting actuators.
• DRN 5 601 / 611: For 5/2 or 5/3 NAMUR valves, DN 5, 650 l/min, 0.5–10 bar.
• DRN 5 128: NAMUR 1/2”, DN 8, 1500 l/min.

Function in Actuator Assemblies

DRN 3 plates regulate supply air to single-acting actuators and exhaust air from the spring chamber. DRN 5 variants independently control opening and closing speeds in double-acting actuators. Series 601 allows manual knob adjustment; 611 uses screwdriver adjustment to prevent unauthorized changes.

Selection Criteria

Selection is based on:

• Single-acting or double-acting actuator type
• Valve type: 3/2, 5/2, or 5/3 NAMUR
• NAMUR interface size: 1/4” or 1/2”
• Required opening/closing time
• Instrument air pressure
• Manual or tamper-resistant adjustment requirement

Applications and Maintenance

Suitable for butterfly valves, ball valves, and dampers with pneumatic actuators. Maintenance includes inspection of NAMUR O-rings, mounting screws, air cleanliness, adjustment stability, and stroke time symmetry after intervention on the valve or actuator. Compatible with standard instrument air; check for media compatibility and sealing integrity in critical applications.