Pneumatic actuator - DP | ARI

Pneumatic Linear Actuator ARI-DP

The ARI-DP actuator converts a pneumatic control signal into linear stem movement for control and shut-off valves. Series variants include DP30, DP32, DP33, DP34, DP34T, DP34Tri, and DP35, supporting strokes up to 120 mm and supply air pressures up to 6 bar, depending on model.

Operation and Selection

• Rolling diaphragm design provides linear force over extended strokes.
• Spring return function ensures fail-safe positioning on air loss.
• Available as spring-extend or spring-retract, depending on process safety requirements.
• Selection based on required seating force, valve stroke, available instrument air pressure, and fail-safe position.

Operating Conditions

Standard ambient temperature range: -10 to +80 °C. Special versions available for lower temperatures, requiring dry instrument air at sub-zero conditions. C5-M construction available for environments with increased corrosion protection requirements.

Materials and Sealing

Stem materials: X20Cr13 / 1.4021 or 1.4571. Sealing via NBR O-rings, PTFE + 25% C guides, and EPDM50 or 42CR stem bellows. This configuration minimizes ingress of contaminants and reduces actuator maintenance frequency.

Automation Accessories

Available options: handwheel, 3/2 solenoid valves, stroke time throttle valves, lock-up valve for air failure, filter-regulator with gauge, limit switches, inductive sensors, analog position indicator, pneumatic or electro-pneumatic positioner. Accessory mounting per DIN IEC 60534-6.

Applications

Used on control valves for steam, water, condensate, thermal oil, glycol, gases, and auxiliary industrial networks. Media compatibility and PN/ANSI pressure classes are determined by the valve body, seat, and sealing—not by the actuator.

Frequently Asked Questions

When to select DP34T or DP34Tri?
For applications requiring higher closing force or longer stroke than standard DP32–DP34 variants.

What should be checked during maintenance?
Air pressure and quality, filter-regulator condition, pneumatic line leakage, O-ring, bellows, and guide condition, and correct zero/stroke adjustment.