Namur Valves 3/2 way & 5/2 way

NAMUR solenoid valves 3/2 & 5/2‑way for pneumatic actuators – standard interface for reliable valve control

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pneumatic single acting drives

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Electric Part-Turn Actuator

J4C Typen Standard, Stellungsregler, BSR Akkupack, Stellungsregler + Akkupack, Drehmoment 10Nm - 300Nm, Befestigung in Standard und auf Anfrage (9mm - 22mm), Spannung 24V - 230V - 240V

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Norgren Magnetventile – Serie 9710000 Namur-Magnetventile

Die Norgren Namur Magnetventile der Serie mit der Artikelnummer 9710000305002400 sind kombinierte 5/2‑ und 3/2‑Wegeventile mit NAMUR‑Schnittstelle für pneumatische Automatisierungssysteme. Sie verfügen über ein robustes, eloxiertes Aluminiumgehäuse, eine mechanische Feder‑Rückstellung und eine manuelle Handhilfsbetätigung. Mit einem Durchfluss von bis zu 750 l/min und einem Betriebsdruck von 2 – 8 bar erfüllen diese Ventile anspruchsvolle Anforderungen in Industrie‑ und Automationsanwendungen. :contentReference[oaicite:0]{index=0}

Die Serie ist in Varianten mit 24 V DC und 230 V AC Spannung verfügbar, jeweils mit NAMUR Anschlussbild und G1/4" Anschlussgröße. Durch die einstellbare 5/2‑ oder 3/2‑Funktion können sie flexibel in pneumatische Schaltungen integriert werden.

FESTO Namur Solenoid Valves – VSNC‑FC‑M52‑MD‑G14 Series

Our FESTO Namur solenoid valves from the VSNC‑FC‑M52‑MD‑G14 series deliver versatile pneumatic switching solutions for automated systems. The VSNC‑FC‑M52‑MD‑G14‑F8‑3WB2 model is a convertible 5/2 or 3/2‑way solenoid valve with NAMUR interface, mechanical spring return, and a 230 V AC coil — designed for 2.5 – 10 bar pressure and up to 1,250 l/min nominal flow.

The VSNC‑FC‑M52‑MD‑G14‑F8‑1B2 model features similar functionality but with a 24 V DC coil, making it suitable for a wide range of pneumatic control circuits where DC operation is required.

The VSNC‑FC‑M52‑MD‑G14‑F8‑1AB2 variant includes a 24 V A/C coil option, offering flexibility across different voltage requirements, along with the NAMUR interface and monostable mechanical spring return.

For demanding industrial applications that require electrical safety and integrated connector options, the VSNC‑FC‑M52‑MD‑G14‑FN‑1A1‑EX4‑A model is ideal, combining the standard convertible 5/2 or 3/2 valve function with a 24 V DC coil and integrated plug (Form A).

Frequently Asked Questions – NAMUR Solenoid Valves

A NAMUR solenoid valve is an electropneumatic pilot valve that switches control air to a pneumatic part-turn actuator, converting an electrical control signal (24V DC, 24V AC, or 230V AC) into a pneumatic actuation command – and thereby opening or closing the process valve:

Electrical input signal (from a PLC/DCS output card or manual pushbutton) energises the solenoid coil of the valve
Pneumatic output: The solenoid valve switches the control air path to the actuator chamber – the actuator rotates the process valve to the commanded position (open/close)
Spring return: On power failure or signal loss, the solenoid valve returns to its de-energised position and drives the actuator to its fail-safe position (the process valve opens or closes depending on the actuator configuration – fail-open or fail-close)
NAMUR interface (VDI/VDE 3845 / IEC 60534-6): The solenoid valve mounts directly onto the standardised NAMUR hole pattern of the actuator – no external tubing or hose connections between solenoid valve and actuator; minimal dead volume, fast switching response

The NAMUR solenoid valve is the essential interface between the electrical control system (PLC/DCS/fieldbus) and the pneumatic valve actuation in any automated plant.

The choice between a 3/2-way and 5/2-way solenoid valve depends entirely on the type of pneumatic actuator being controlled:

3/2-way solenoid valve – for single-acting (spring-return) actuators (SA):

Ports: 3 ports (supply P, output A, exhaust R) and 2 switching positions
Function: Switches control air to one actuator chamber; the return stroke is provided by the internal spring of the actuator
Use with: All single-acting (spring-return) actuators – spring-to-close (Fail-Close / NC) or spring-to-open (Fail-Open / NO)
Fail-safe behaviour: On power failure the 3/2 valve exhausts the actuator chamber; the actuator spring drives the valve to its safe position – the preferred choice for emergency shutdown duty where a defined safe position is required
FERGO actuator code: Actuators designated SA (Single-Acting) or with spring-return require a 3/2-way solenoid valve

5/2-way solenoid valve – for double-acting actuators (DA):

Ports: 5 ports (supply P, 2× outputs A/B, 2× exhausts R/S) and 2 switching positions
Function: Switches control air alternately between the two actuator chambers; both the opening and closing strokes are pneumatically powered
Use with: All double-acting actuators (DA); higher torque available in both directions; no spring influence on output torque
Fail-safe behaviour: On power failure the double-acting actuator remains in its last position (no defined fail-safe position without additional measures) – for safety-critical shutdowns, a single-acting actuator with 3/2 solenoid valve is therefore preferred
FERGO actuator code: Actuators designated DA (Double-Acting) require a 5/2-way solenoid valve

Combination valve (Norgren 9710000): The Norgren 9710000 is available as a combined 5/2 and 3/2-way valve with a spare adapter plate – one housing covers both actuator types, simplifying spare parts inventory.

FERGO stocks NAMUR solenoid valves from Norgren and Festo, plus approved ATEX versions:

Norgren solenoid valve 9710000 (combined 5/2 + 3/2):

Type: Combined 5/2- and 3/2-way valve with spare adapter plate – one housing, both actuator types
Connection: G¼"; NAMUR hole pattern per VDI/VDE 3845
Operating pressure: 2–8 bar; flow rate: 750 l/min
Housing: Anodised aluminium; spring return; manual override with detent as standard
Available in: 24V DC (coil 3050) and 230V AC (coil 3050), each with DIN plug 43650 B

Festo NAMUR solenoid valve MSSD-F / VSNC-FC (5/2 or 3/2 reversible):

Type: Monostable, pilot-operated 5/2- or 3/2-way valve, mechanically reversible by spring
Connection: G¼"; NAMUR hole pattern; MSSD-F plug socket
Operating pressure: 2.5–10 bar; nominal flow: 1,250 l/min (significantly higher than Norgren)
Medium temperature: −20°C to +60°C
Available in: 24V DC, 24V AC (50–60 Hz), 230V AC (50–60 Hz)

Air-spring versions (3/2 and 5/2, standard + ATEX):

Housing: Anodised aluminium; internals: brass and plastic; spool: stainless steel; seals: NBR
Connection: G¼"; operating pressure: 1.5–10 bar (standard) or 2–8 bar (ATEX); protection class: IP65
ATEX version: Solenoid coil Ex II 2 G/D, Ex ia IIC T6 (intrinsic safety); ATEX plug; NAMUR intermediate plate ZPN 5A (5 mm) included; supply only from certified intrinsically safe circuits (U ≤ 28V, I = 25–115 mA)

All valves are available directly from the FERGO webshop. For project quantities or special voltages: shop@fergo-valve.com | +49 21 31 / 15 39 28-0.

NAMUR (Normenarbeitsgemeinschaft für Mess- und Regeltechnik in der chemischen Industrie – the German process instrumentation standards body) defined the standardised mounting and port geometry for solenoid valves on pneumatic part-turn actuators in recommendation VDI/VDE 3845 (equivalent to IEC 60534-6). This NAMUR hole pattern is now the global standard for valve automation in the process industries.

Advantages of direct NAMUR mounting:

No external tubing or hose connections: The solenoid valve bolts directly onto the actuator; the control air ports are integrated into the NAMUR hole pattern – no external pipework between solenoid valve and actuator required
Short air paths and minimal dead volume: Control air travels the shortest possible distance, resulting in fast switching times and precise actuator response
Fewer leak points: No pipe fittings between solenoid valve and actuator; reduced maintenance and increased operational reliability
Universal interchangeability: Any NAMUR-standard solenoid valve fits any NAMUR-standard actuator – regardless of manufacturer; simplified spare parts supply and system integration
Compact integrated unit: Actuator + solenoid valve + (optional) limit switch box form an integrated, cabinet-ready unit mounted directly on the process valve

NAMUR hole pattern dimensions: The standard defines bolt spacing, thread size (typically M5), and the air channel geometry for supply (P), outputs (A/B), and exhaust (R/S). All FERGO actuators carry the NAMUR hole pattern – all solenoid valves stocked in the shop mount directly without adapters.

In plants where explosive atmospheres may be present (flammable gases, vapours, or dusts), all electrical equipment – including solenoid coils – must be approved for use in the relevant hazardous zone. FERGO's ATEX NAMUR solenoid valves are designed for these requirements:

ATEX certification of FERGO NAMUR solenoid valves:

Marking: Ex II 2 G/D Ex ia IIC T6
Equipment category 2 → suitable for Zone 1 (gas) and Zone 21 (dust) as well as Zone 2 / Zone 22
Protection type: Intrinsic safety (Ex ia) – the highest-integrity Ex protection type; the coil is powered from a certified intrinsically safe circuit so that no ignition-capable energy can be released under fault conditions
Gas group IIC → suitable for the most hazardous gases including hydrogen (H₂), acetylene (C₂H₂), and carbon disulphide (CS₂)
Temperature class T6 → maximum surface temperature 85°C; suitable for gases with ignition temperature > 85°C

Electrical requirements for intrinsic safety:

Supply exclusively from a certified intrinsically safe circuit (Zener barrier or galvanic isolator)
Operating voltage U ≤ 28V; current I = 25–115 mA (depending on coil variant)
Included in delivery: ATEX plug and NAMUR intermediate plate ZPN 5A (5 mm spacer plate for correct mounting on NAMUR hole pattern)

Typical ATEX NAMUR valve applications: Chemical and petrochemical plants; refineries; gas pipelines; solvent processing plants; ATEX zones in pharmaceutical and food production; any installation where automated process valves operate in hazardous areas.

The correct solenoid valve voltage depends on the control system architecture of the plant:

24V DC – the PLC standard:

By far the most common specification in modern industrial plants; PLC/DCS digital output cards deliver 24V DC control signals as standard
Low power consumption; safe operation in wet or hazardous environments (also usable in ATEX Ex ia intrinsic safety circuits)
Recommendation: First choice for all new installations with PLC/DCS control; mandatory for ATEX Ex ia applications

24V AC (50–60 Hz):

For plants with 24V AC control circuits (less common in new plants; more frequent in legacy installations and certain regional standards)
Festo MSSD-F version available; same mechanical specification as 24V DC

230V AC (50–60 Hz) – for direct mains switching:

Direct supply from mains voltage without a control transformer; suitable for simple relay-based panels without a PLC, manual switch operation, or retrofits in legacy installations
Both the Norgren 9710000 and Festo MSSD-F are available in 230V AC
Not suitable for ATEX intrinsic safety applications (Ex ia requires low voltage ≤ 28V)

Selection tip: Always specify 24V DC for new installations – PLC-compatible, low power, ATEX-capable. For existing plants, check the available control voltage and order the matching coil. All FERGO solenoid valves have a field-replaceable coil, so if the voltage needs to change during a retrofit, only the coil needs to be swapped.

The NAMUR solenoid valve is one module in a standardised, fully integrated automation assembly that FERGO supplies as a complete, factory-assembled package on any process valve. The typical build of an automated valve station:

Process valve (e.g. butterfly valve, ball valve, knife gate valve) – the pipeline valve with ISO 5211 actuator mounting flange
Pneumatic part-turn actuator (DA or SA) – direct-mounted on the ISO 5211 flange of the process valve; carries the NAMUR hole pattern on top
NAMUR solenoid valve (3/2 for SA, 5/2 for DA) – direct-mounted on the NAMUR hole pattern of the actuator; electrical connection via DIN plug
Limit switch box (Switchmaster) – also mounted on the NAMUR hole pattern or side flange; provides position feedback (open/closed) to the PLC/DCS; available in IP67, ATEX, with mechanical microswitches or inductive sensors
Compressed air supply – supply line to port P of the solenoid valve (typically 4–7 bar)
Electrical wiring – PLC/DCS output → DIN plug solenoid valve (command signal); limit switch box → PLC/DCS input (position feedback)

FERGO supplies these assemblies factory-assembled and tested – process valve + actuator + solenoid valve + limit switch box as a ready-to-install unit. Contact shop@fergo-valve.com for project configurations.

The manual override (also manual override button or HHB – Handhilfsbetätigung) is a mechanical override function that allows the solenoid valve – and therefore the pneumatic actuator – to be operated manually, independently of the electrical control signal. On the Norgren 9710000, the manual override with detent is included as standard; all other FERGO solenoid valves also carry a manual override as standard.

Main applications of the manual override:

Commissioning and function testing: Before the electrical control system is energised, the complete actuator mechanism – solenoid valve, actuator, process valve – can be manually cycled to verify correct operation and end positions, without requiring the PLC/DCS to be live
Maintenance and fault diagnosis: In the event of electrical faults or PLC failure, the actuator can be driven manually to the working position to maintain process continuity, or to open/close a valve for maintenance access
Emergency operation: In emergencies (control failure, cable break), on-site personnel can manually position the valve without requiring the electrical control system or any external tools
Override types: Without detent (push and hold, self-resetting) or with detent (latches in manual position for sustained operation; released by rotating or pressing again) – the detent version is standard on the Norgren 9710000 and the air-spring variants

Important note: After maintenance or functional testing, always confirm the manual override has been returned to the normal (non-latched) position before resuming automatic operation. If the override remains latched, the actuator will no longer follow the electrical control signal.

Electrically & Pneumatically Operated Namur Valves