Description
1/8"–1/4" BSP Proportional Solenoid Valve 24V DC – GEM-PR
The Baccara GEM-PR is a compact 2/2 way normally closed proportional solenoid valve designed for precise, adjustable flow control of water, neutral gases, light oils and other compatible fluids. Unlike conventional on/off solenoid valves, the GEM-PR provides continuously variable valve opening in response to electrical coil current, making it ideal for industrial automation, process control, dosing systems and specialist OEM equipment.
Available in 1/8" and 1/4" BSP female threaded connections, the GEM-PR features a direct acting design that operates from technical vacuum up to 16 bar, depending on the selected orifice diameter. With seven orifice options from 0.8mm to 4.0mm, the valve can be configured to balance flow capacity, pressure capability and proportional control performance.
The 24V DC solenoid operates with a controlled coil current of 100–500mA, allowing precise adjustment of the valve opening using a suitable proportional valve driver or PWM controller.
Proportional Flow Control & Operation
The GEM-PR is a 2/2 way normally closed direct acting proportional solenoid valve.
With no electrical current applied, the return spring holds the valve closed.
As electrical current increases, the solenoid generates a magnetic force that acts against the return spring, progressively moving the valve plunger and increasing the valve opening.
Reducing the coil current decreases the magnetic force, allowing the spring to reduce the valve opening.
Power OFF → Valve normally closed.
Increasing Current → Valve opening increases.
Reducing Current → Valve opening decreases.
The relationship between electrical current and flow depends on the selected orifice, differential pressure and operating conditions.
For best proportional regulation, the manufacturer recommends a suitable PWM control unit operating at 500Hz with a controlled coil current.
Port Sizes & Valve Construction
The GEM-PR Series is available with:
- 1/8" BSP female threaded ports
- 1/4" BSP female threaded ports
- Optional 1/8" NPT connections
- Optional 1/4" NPT connections
Body material options include:
- Brass
- 316 stainless steel
- Aluminium
Internal solenoid operator components are manufactured from 300/400 series stainless steel, with PTFE guide rings.
Available seal materials:
The choice of body and sealing materials allows the valve to be configured for different industrial fluids and operating environments.
Orifice Sizes, Pressure Ratings & Flow
The GEM-PR is available with seven orifice options, each offering a different maximum operating pressure and flow coefficient.
0.8mm Orifice
- Maximum Pressure: 16 bar
- Kv Flow: 0.6 L/min
1.2mm Orifice
- Maximum Pressure: 12 bar
- Kv Flow: 1.1 L/min
1.6mm Orifice
- Maximum Pressure: 10 bar
- Kv Flow: 1.7 L/min
2.0mm Orifice
- Maximum Pressure: 8 bar
- Kv Flow: 2.5 L/min
2.4mm Orifice
- Maximum Pressure: 6 bar
- Kv Flow: 3.5 L/min
3.0mm Orifice
- Maximum Pressure: 3.5 bar
- Kv Flow: 4.5 L/min
4.0mm Orifice
- Maximum Pressure: 2 bar
- Kv Flow: 5.0 L/min
The valve operates from technical vacuum up to the maximum pressure rating of the selected orifice.
Larger orifices provide greater flow capacity but have lower maximum pressure ratings. Correct selection is essential for reliable proportional regulation.
Pressure & Temperature Specifications
The GEM-PR Series is designed for compatible industrial fluids within the following operating conditions:
- Pressure Range: Technical vacuum to 2–16 bar, depending on orifice
- Media Temperature: -10°C to +80°C
- Ambient Temperature: -10°C to +55°C
- Maximum Media Viscosity: 21mm²/s (21 cSt)
- Suitable Media: Neutral gases, water and compatible oils
Fluid compatibility must be confirmed against the selected body and seal materials.
Electrical Control & Performance
The GEM-PR uses a 24V DC proportional solenoid operator.
Electrical specifications:
- Nominal Supply Voltage: 24V DC
- Operating Coil Current: 100–500mA
- Recommended PWM Frequency: 500Hz
- Ingress Protection: IP65 with connector
- Electrical Connection: DIN 43650 Form A
- Alternative Connection: 2 × 18AWG flying leads, 300mm long
Proportional control performance, measured at constant differential pressure:
- Hysteresis: Less than 5% of full scale
- Repeatability: Less than 3% of full scale
- Sensitivity: Less than 2% of full scale
The coil current must be controlled using suitable electronics. Applying an uncontrolled voltage is not an appropriate substitute for a proportional current driver.
Selection & Installation Guidelines
For effective proportional flow regulation, the manufacturer recommends careful consideration of the valve pressure drop and selected Kv value.
The pressure drop across the valve should preferably represent at least 30–50% of the total system pressure drop.
Where the valve is operated without a dedicated control unit, the manufacturer recommends a maximum pressure approximately 1.2 times the working pressure to improve regulation performance.
The valve includes an adjustable upper screw for setting the opening threshold. Inlet pressure should remain as constant as possible during operation.
Mounting is permitted in any position, although upright installation is preferred.
Because proportional flow control is sensitive to operating conditions, technical assistance is recommended when selecting the valve for specialist applications.
Typical Applications
- Industrial proportional flow control
- Water flow regulation
- Gas flow control systems
- Dosing and dispensing equipment
- Laboratory automation
- Medical equipment and OEM systems
- Process control machinery
- Test and measurement equipment
- Automated fluid distribution
- Specialist low-flow control systems
Technical Specification
Manufacturer: Baccara
Series: GEM-PR
Valve Type: 2/2 way normally closed
Operation: Direct acting proportional
Port Sizes: 1/8" and 1/4" BSP
Optional Connections: NPT
Body Materials: Brass, 316 stainless steel or aluminium
Solenoid Internals: Stainless steel
Seal Options: NBR, FKM or EPDM
Guide Rings: PTFE
Orifice Sizes: 0.8–4.0mm
Maximum Pressure: 2–16 bar depending on orifice
Minimum Pressure: Technical vacuum
Kv Flow Factor: 0.6–5.0 L/min
Suitable Media: Neutral gases, water and compatible oils
Maximum Viscosity: 21 cSt
Media Temperature: -10°C to +80°C
Ambient Temperature: -10°C to +55°C
Nominal Voltage: 24V DC
Operating Current: 100–500mA
Recommended PWM Frequency: 500Hz
Hysteresis: Less than 5% F.S.
Repeatability: Less than 3% F.S.
Sensitivity: Less than 2% F.S.
Ingress Protection: IP65 with connector
Electrical Connection: DIN 43650 Form A
Mounting: Any position, preferably upright
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