Solenoid Valves - 2/2-way valves | Hafner

Hafner 2/2 Solenoid Air Valves

The Hafner 2/2 series comprises monostable solenoid valves for on/off control of compressed air in industrial automation. MH variants are normally closed (N.C.) and include manual override for commissioning, circuit testing, and maintenance without PLC activation.

Types and Operation

• MH 211 012 / MH 211 015: Direct-acting, spring return, M5 or G 1/8” ports, flow rate 40–50 l/min, coil consumption 3 W DC or 5 VA AC. Operating pressure range -0.9…10 bar, suitable for technical vacuum applications.
• MH 211 305 / MH 211 309: Direct-acting, 3 mm orifice, G 1/8” or G 1/4” ports, flow rate 200 l/min, pressure 0…7 bar, coil 7.5 W DC or 8.5 VA AC. Industry B 22 mm connector; cable options available.
• MH 210 501 / MH 210 701: 2/2 N.C., actuated by continuous electrical signal with pneumatic return. G 1/8” or G 1/4” ports, flow rates 650 and 1250 l/min, operating pressure 2…10 bar.

Valve Selection Criteria

Selection is based on available pressure, required flow rate, port size, and coil voltage. For pilot lines, small signals, or vacuum pick-up, MH 211 012/015 are recommended. For higher flow in main air lines, MH 210 501/701 are preferred, provided minimum 2 bar supply pressure is available.

Industrial Applications

Typical uses include:

• Pneumatic machine automation
• Isolation or venting of auxiliary air lines
• Control of small actuators
• Packaging, assembly, and material handling systems
• Auxiliary functions in automation panels

FAQ

When is a direct-acting valve selected?
When operation is required without minimum pilot pressure or in low-flow circuits.

What does N.C. mean?
Valve remains closed without electrical supply and opens when the coil is energized.

What is checked during maintenance?
Air cleanliness, coil condition, seat tightness, orifice contamination, and correct supply voltage.