Pneumatically Actuated Valves - Quick-exhaust valves | Hafner

Hafner Quick Exhaust Valves

Hafner SE series quick exhaust valves are pneumatic devices designed to reduce decompression time in cylinders and pneumatic chambers. Installed close to the actuator, they allow local venting of air through port R, bypassing the main control valve and return piping. The series operates with compressed air and is intended for in-line installation.

Available Types

• SE 501: G 1/8”, flow rate 564 l/min, pressure range 0.3–10 bar.
• SE 801: G 1/4”, flow rate up to 1188 l/min, pressure range 0.3–10 bar.
• SE 121: G 1/2”, flow rate up to 3600 l/min, pressure range 0.3–10 bar.

Flow rates are specified at P1 = 6 bar, ΔP = 1 bar. Valve bodies are aluminum. Standard temperature range is -10…+50 °C.

Operation in Circuit

In standard operation, the valve supplies air from P to A and rapidly exhausts from A to R when supply pressure drops. It can also function as a check valve (with R plugged) or as a pneumatic OR element with supply to P and R, output from A.

Selection Criteria

Selection is based on:

• cylinder volume and required exhaust time,
• pipe diameter and thread size (G 1/8”, G 1/4”, G 1/2”),
• available operating pressure,
• permissible exhaust noise and silencer requirements,
• installation position—preferably as close as possible to the actuator.

Applications

Used in pneumatic cylinders, presses, clamping systems, packaging machines, grippers, and automation where exhaust delay affects cycle time.

Maintenance

Inspect for seat contamination, leakage at port R, blocked silencers, air moisture, and mechanical stress at connections. For contaminated air, install a filter upstream of the circuit.