ATEX Ex ia Bi-Stable NAMUR Solenoid Valve – Rotex 57450V02IS-6
The Rotex 57450V02IS-6 is an ATEX and IECEx Ex ia intrinsically safe 5/2 way bi-stable NAMUR solenoid valve designed for hazardous-area pneumatic actuator control where the actuator must remain in its last commanded position after the electrical signal is removed.
Featuring double-solenoid bi-stable operation with internal pilot control, the valve mounts directly onto compatible NAMUR pneumatic actuators, reducing external pipework and simplifying hazardous-area valve automation installations.
Available with a hard-anodised aluminium or 316 stainless steel body, the 57450V02IS-6 operates from 2 to 8 Bar and uses low-power 24V DC, 2.3W intrinsically safe solenoid operators.
Valve Function & Operation
Function: 5/2 way bi-stable
Actuation: Double solenoid
Operation: Internally piloted
The Rotex 57450V02IS-6 is designed primarily for direct control of double-acting pneumatic actuators.
Energising one solenoid switches the valve and actuator in one direction. Energising the opposite solenoid switches the valve back.
Unlike a monostable spring-return NAMUR valve, the bi-stable design maintains its last switched position when the electrical signal is removed. This makes it particularly useful where actuator position must be maintained without continuously energising a solenoid.
Operating pressure: 2 to 8 Bar
NAMUR Mounting & Connections
The valve is designed for direct NAMUR actuator mounting, eliminating much of the external pneumatic tubing normally required between a separate solenoid valve and actuator.
Pneumatic connection:
1/4" BSP
1/4" NPT
Orifice: 6mm
This compact arrangement is particularly advantageous on automated process valves, actuator packages and process skids.
Construction & Materials
Body options:
Hard-anodised aluminium
316 stainless steel
Internals:
Aluminium
Brass
316 stainless steel
Available seat/seal materials:
NBR
FKM (Viton®)
EPDM
Fluorosilicone
Media:
Air
Inert gases
Valve temperature range: -25°C to +75°C
The 316 stainless steel body option is particularly useful for installations requiring greater external corrosion resistance or more demanding environmental protection.
Manual Override
Manual override is provided for commissioning, maintenance and local actuator operation.
Available functions include:
Push – momentary manual operation
Push and turn – mechanically retains the selected manual position
With a bi-stable valve, this provides useful local control of the actuator during commissioning or when an electrical control signal is unavailable.
Intrinsically Safe Solenoid
Coil size: III 14mm
Voltage: 24V DC
Power: 2.3 Watts
Insulation: Class H
Protection: IP67
The Ex ia enclosure incorporates integrated electrical terminals and is available in:
Powder-coated aluminium
316 stainless steel
Conduit entry:
1/2" NPT
M20 × 1.5
ATEX & IECEx Intrinsic Safety
The Rotex 57450V02IS-6 solenoid operators are certified for intrinsically safe hazardous gas and dust applications.
Approvals: ATEX & IECEx
IECEx certificate: IECEx BAS 12.0128X – Issue 1
ATEX certificate: Baseefa12ATEX0243X – Issue 1
Gas marking:
Ex ia IIC T5 Ga
-60°C ≤ Ta ≤ +75°C
Ex ia IIC T6 Ga
-60°C ≤ Ta ≤ +60°C
Dust marking:
Ex ia IIIC T200 125°C IP67 Da
-60°C ≤ Ta ≤ +75°C
The valve's stated operating temperature is -25°C to +75°C; the wider values above relate to the certified Ex ia operator's ambient marking and should not be interpreted as extending the valve's media or mechanical temperature range.
Intrinsically Safe Parameters
Minimum operating parameters:
Voltage: 10V
Current: 20mA
Power: 0.20W
Entity parameters:
Ui: 32V DC
Ii: 230mA
Pi: 2.3W
Li: 0
Ci: 0
The associated intrinsically safe barrier or galvanic isolator must be selected to comply with these certified entity parameters and the requirements of the complete Ex ia circuit.
Typical Applications
The Rotex 57450V02IS-6 is particularly suited to hazardous-area double-acting pneumatic actuator control in oil and gas installations, petrochemical plants, chemical processing, offshore equipment, tank farms, refineries, process skids and automated process valve assemblies.
Why Choose the Rotex 57450V02IS-6?
The main advantage of the 57450V02IS-6 is the combination of direct NAMUR mounting, Ex ia intrinsic safety and bi-stable positional control.
Unlike the monostable 51450V02IS-6, the 57450V02IS-6 retains its last commanded position rather than automatically spring-returning when the electrical signal is removed. This makes it the better choice where a double-acting actuator needs to stay in its last position on loss of the control signal.
With 24V DC low-power 2.3W solenoids, IP67 protection and aluminium or 316 stainless steel construction, it provides a robust solution for critical hazardous-area actuator automation.
