NAMUR Interface Valves by Automatic Valve

Key Features and Design Advantages

Automatic Valve NAMUR interface valves incorporate several engineering features that set them apart in demanding industrial environments. The solenoid pilot design uses full air line pressure to shift the valve, ensuring fast and reliable actuation while the solenoid itself is guaranteed against burnout. Weather-proof coils are hermetically sealed as an integral, water-tight molded unit, enabling robust performance in rugged outdoor and industrial environments.

The proprietary bidirectional tapered Tee-Seal is a signature feature of Automatic Valve products. This seal design eliminates sticking problems commonly encountered in conventional spool valves. The Tee-Seal has been tested tough and proven reliable according to SAE specifications, enduring rust and water injection every 864,000 cycles over a 20-million-cycle life test. Manual override capability allows operators to use the valve manually in case of electrical failure or for quick cycle testing, with push non-locking, push turn-locking, and extended turn-locking options available.

Additional design advantages include field-convertible external pilot supply, DIN EN 175301-803 Form A and Form B electrical connectors, M12 connectors, molded coil with 18-inch flying leads, and half-inch conduit coils with 30-inch leads. Enclosure ratings of NEMA 4X and IP65 ensure reliable protection against water and dust ingress in virtually any installation environment.

Specifications and Operating Conditions

Automatic Valve NAMUR interface valves are engineered for broad operating flexibility. Standard temperature models operate from -20 degrees F to 123 degrees F (-29 degrees C to 50 degrees C), high temperature models handle 0 degrees F to 180 degrees F (-18 degrees C to 82 degrees C), and low temperature models extend down to -40 degrees F to 123 degrees F (-40 degrees C to 50 degrees C). For temperatures below 40 degrees F, air must be free of water vapor to prevent ice formation.

Operating pressure ranges are tailored to each valve function. The D06 Series 3/2 valves operate from 0 to 150 psig (0 to 10.3 bar), while D20 Series 3/2, 5/2, and 5/3 valves require minimum pressure of 35 to 50 psig depending on function. External pilot supply pressure is available for all valve functions. Solenoid options include DC voltages of 12V and 24V with power consumption as low as 0.7 watts for energy-efficient installations, and AC options at 120V and 240V at 60 Hz.

Construction materials include aluminum bar stock and stainless steel (Grade 303 and Grade 316) valve bodies, Polyamide 66 solenoid bodies, and aluminum spools. Seal options include Buna-N for general purpose applications and Fluoroelastomer for chemical resistance. Port connections are available in NPT and G thread configurations, and all valves accept standard 5 mm NAMUR fasteners with optional 10-24 and 10-32 mounting kits.

Available Valve Functions and Series

The NAMUR interface valve line from Automatic Valve covers three primary valve functions to address diverse pneumatic control requirements. The 3/2 normally closed valve is available in both D06 and D20 series, offering single solenoid actuation with top, left, or right pilot mounting positions. These three-way valves are ideal for controlling single-acting pneumatic actuators and spring-return applications.

The 5/2 valve configuration provides five-way, two-position directional control for double-acting actuators. Available exclusively in the D20 series, these valves feature single solenoid (left or right pilot) and double solenoid actuation options. With Cv 1.8 (1,800 Nl/min) flow capacity and 1/4-inch ports, the 5/2 NAMUR valve is suited for medium-duty actuator control in process automation.

For applications requiring a center position, the 5/3 valve offers closed center, open center, and power center configurations. These double solenoid valves maintain a stable center position when both solenoids are de-energized, providing an additional layer of safety and control flexibility. All valve functions are available in standard, high, and low temperature variants, with model number configurators that allow engineers to specify every option from valve body height and coil type to seal material and port thread.

NAMUR Mounting Accessories

Automatic Valve offers a comprehensive range of NAMUR mounting accessories designed to extend the functionality and versatility of every NAMUR interface valve installation. The Speed Control Valve (Model A7106-554) mounts between the directional control valve and the actuator on the NAMUR pad, functioning as a dual-port flow control with easily adjustable needle valves for precise speed regulation. Operating pressure ranges from 35 to 150 psig.

The Interposed Lockout and Vent Valve (Model D20-106) mounts between the solenoid valve and actuator to prevent unintended air flow during maintenance operations. This energy isolation device adds a critical safety layer to any NAMUR valve installation. The 1/4 NPT NAMUR Adapter (Model D20-114) provides standard 1/4 NPT connections for mounting remote control valves and accessories, while the 90-degree Mounting Plate (Model A8022-438) allows horizontal installation with the valve orientated 90 degrees to the actuator.

Additional accessories include the NAMUR Quick Exhaust (Model D20-111, available in aluminum or stainless steel) for improved closing speed and protection against corrosive atmospheres, the Dual Flow Control (Model D20-112) for speed control of double-acting actuators, the Dual Function Flow Control (Model D20-113) for independently controlling opening and closing speeds of spring-return actuators, and a Transition Plate (Option P, Model A8021-339) for installations where the solenoid valve sealing face extends beyond the mounting surface.

Ordering and Model Number Configuration

Automatic Valve uses an intuitive model number configurator system that allows engineers and procurement teams to specify exactly the NAMUR valve configuration required for their application. Each model number encodes the series (D06 or D20), valve body height, valve function, actuation type, solenoid location, voltage, seal material, pilot supply, coil type, dustproof options, body material, port thread, manual override, mounting kit, and transition plate options.

For example, a model number such as D2013GAWR-DB indicates a D20 series, 1-inch body height, 3/2 normally closed, single solenoid with top-mounted AWR actuation, and 24V DC power. Option codes are added in alphabetical order, and only one coil type can be selected per valve. Engineers can reference the product catalog or contact Automatic Valve directly for assistance with complex configurations or custom requirements.

Downloadable CAD models are available for all NAMUR interface valves, enabling seamless integration into plant design and engineering workflows. The comprehensive product catalog provides detailed dimensional drawings for every series and model variant, including D2003 and D2013 configurations for both single and double solenoid valves.

Frequently Asked Questions About NAMUR Interface Valves

What is a NAMUR interface valve and how does it work?

A NAMUR interface valve is a solenoid pilot controlled directional control valve designed to mount directly to pneumatic valve actuators according to the VDI/VDE 3845 standard. The valve uses air pressure directed by the solenoid pilot to shift an internal spool, which routes compressed air to and from the actuator ports. Automatic Valve NAMUR valves feature a balanced spool construction with a proprietary Tee-Seal that eliminates sticking and ensures reliable operation over millions of cycles.

What SIL rating do Automatic Valve NAMUR valves achieve?

Automatic Valve NAMUR interface valves are certified by SGS-TUV Saar in accordance with IEC 61508. They achieve Safety Integrity Level 2 (SIL 2) in singular application with HFT equal to 0, and SIL 3 with Performance Level e in redundant application with HFT greater than or equal to 1. This makes them suitable for safety-critical process automation applications where functional safety is required.

What temperature ranges are available for NAMUR valves?

Automatic Valve offers three temperature ranges for NAMUR interface valves. Standard temperature models operate from -20 degrees F to 123 degrees F (-29 degrees C to 50 degrees C). High temperature models handle 0 degrees F to 180 degrees F (-18 degrees C to 82 degrees C). Low temperature models extend down to -40 degrees F (-40 degrees C). For temperatures below 40 degrees F, the air supply must be free of water vapor to prevent ice formation.

Can NAMUR valves be configured with stainless steel bodies?

Yes, Automatic Valve NAMUR interface valves are available with stainless steel valve bodies in Grade 303 and Grade 316 options. Stainless steel is ideal for corrosive environments, washdown applications, and installations where material compatibility is critical. Note that stainless steel is not available in the D20 1-1/4 inch valve body height option 03 configuration.

What accessories are available for NAMUR valve installations?

Automatic Valve offers a full range of NAMUR mounting accessories including the Speed Control Valve for adjustable flow regulation, the Interposed Lockout and Vent Valve for maintenance safety, the NAMUR Quick Exhaust for improved closing speed, the Dual Flow Control and Dual Function Flow Control for actuator speed management, the 1/4 NPT NAMUR Adapter for remote mounting, the 90-degree Mounting Plate for horizontal installation, and the Transition Plate for surface-offset mounting situations.