RSG 850B Red Brass Normally Open Direct Acting Solenoid Valve
The RSG 850B is a heavy-duty 2/2 way normally open direct acting piston solenoid valve designed for reliable control of liquids and gases from vacuum and zero differential pressure applications.
In its normal de-energised state the valve remains open, automatically closing when electrical power is applied. This makes the 850B particularly suitable for applications requiring unrestricted flow during normal operation or where a normally open valve function is required.
Unlike conventional pilot-operated solenoid valves, the direct acting piston design does not require a minimum pressure differential to operate, making the 850B suitable for low-pressure systems, vacuum applications and installations where inlet pressure can fall to zero.
Available from 1/2" to 2" BSP with large 15mm to 50mm nominal bores, the 850B combines high flow capacity with working pressures according to valve size and configuration.
The standard valve body is manufactured from corrosion-resistant red brass, with AISI 303 / 1.4305 stainless steel versions also available. NBR, EPDM or FKM seals can be selected according to the media and operating temperature, with a PTFE seat seal available as an option.
Suitable for air, water, oils, vacuum, compatible gases and other fluids with a viscosity below 50 cSt.
Function & Operation
Function: 2/2 way normally open
Operation: Direct acting piston valve
Normal Position: Open when de-energised
Energised Position: Closed
Minimum Differential Pressure: 0 Bar
Port Sizes: 1/2", 3/4", 1", 1 1/4", 1 1/2" and 2" BSP
Optional Connection: NPT thread
Nominal Bore: DN15 to DN50
Orifice: 15mm, 20mm, 25mm, 32mm, 40mm or 50mm according to valve size
Opening Time: 1 second maximum
Closing Time: 0.5 seconds maximum
Materials
Body: Red brass
Optional Body: AISI 303 / 1.4305 stainless steel
Internals: Stainless steel
Seal Options:
✓ NBR: -20°C to +90°C
✓ EPDM: -20°C to +130°C
✓ FKM: -10°C to +120°C
✓ PTFE seat seal available as an option
Ambient Temperature: Maximum +50°C
Pressure & Flow
Working Pressure: According to valve size, body material and configuration
Kv Flow Factor: 4.5 to 49.0 m³/h
Equivalent Flow: Approximately 75 to 817 L/min Kv
The valve requires no minimum differential pressure and can therefore operate from 0 Bar.
Coil & Electrical
Standard Coil: 30 Watt, 60mm diameter
Duty Rating: 100% continuous duty
Protection: IP65 with DIN connector fitted
Electrical Connection: DIN EN 175301-803 Form A
Standard Voltages: 24V DC and 230V AC 50Hz
Voltage Tolerance: ±10%
Special Voltages: Available on request
Installation: Solenoid preferably mounted vertically above the valve body
Media
Suitable for:
✓ Air and compressed gases
✓ Water
✓ Oils
✓ Vacuum applications
✓ Compatible liquids and gases
✓ Fluids with viscosity below 50 cSt
Options
✓ AISI 303 / 1.4305 stainless steel body
✓ NBR, EPDM or FKM seals
✓ PTFE seat seal
✓ Vacuum configuration
✓ Oil and grease-free version
✓ LED DIN connector
✓ 24V DC power-reduction connector
✓ Open / closed position indication
✓ Wall mounting brackets
✓ Explosion-proof version: II 2G Ex m II T4 / II 3D IP65 T130°C
Please note: maximum operating pressure is reduced by approximately 20% when supplied in the explosion-proof configuration.
The RSG 850B provides a robust high-flow normally open solution where conventional pressure-assisted solenoid valves are unsuitable, particularly for zero-pressure, vacuum and demanding industrial process applications.
Pressure:
0.02 Bar (20 mBar), 0.1 Bar (100 mBar), 0.2 Bar (200 mBar), 0.3 Bar (300 mBar), 0.4 Bar (400 mBar), 0.5 Bar (500 mBar), 0.6 Bar (600 mbar), 0.7 Bar (700 mBar), 0.8 Bar (800 mBar), 1 Bar, 1.2 Bar, 1.3 Bar, 1.4 Bar, 1.5 Bar, 1.6 Bar, 2 Bar, 2.5 Bar, 3 Bar, 3.5 Bar, 4 Bar, 4.5 Bar, 5 Bar, 5.5 Bar, 6 Bar, 6.5 Bar, 7 Bar, 7.5 Bar, 8 Bar, 8.5 Bar, 9 Bar, 10 Bar, 12 Bar, 13 Bar, 14 Bar, 15 Bar, 16 Bar
