Description
1/4" PVC or PTFE Acid & Alkali Solenoid Valve – RSG 148
The RSG Type 148 is a 2/2 way normally closed plastic solenoid valve designed for controlling aggressive liquids where conventional brass or stainless steel valves may not provide suitable chemical resistance.
Available with a PVC or PTFE valve body, the Type 148 uses a direct acting design with an isolating PTFE bellows. The bellows separates the solenoid operating mechanism from the process medium, making the valve particularly suitable for acids, alkalis and other chemically aggressive fluids compatible with the selected materials.
Valve Function & Operation
Function: 2/2 Way Normally Closed
Operation: Direct Acting
Design: Seat Valve with PTFE Bellows
Minimum Differential Pressure: 0 Bar
The Type 148 is direct acting and therefore does not require process pressure or a minimum pressure differential to operate.
When the solenoid coil is de-energised, the valve remains closed. Energising the coil lifts the valve mechanism and opens the process flow path.
Isolating PTFE Bellows Design
A key feature of the RSG 148 is its PTFE bellows isolation system.
Rather than relying on a conventional dynamic plunger seal exposed directly to the process fluid, the PTFE bellows isolates the solenoid mechanism from the controlled medium.
This provides important advantages for corrosive fluid applications:
✓ Process Media Isolation
✓ Excellent Chemical Resistance
✓ No Dynamic Stem Seal
✓ Reduced Solenoid Contamination
✓ Suitable for Aggressive Fluids
✓ PVC or PTFE Body Options
Ports & Connections
PVC Body:
✓ 1/4" BSP Thread
✓ 12mm Solvent Cement Socket
PTFE Body:
✓ 1/4" BSP Thread
NPT and special connection configurations can be supplied where available.
Pressure, Orifice & Flow
The Type 148 is available with four nominal orifice sizes. Maximum operating pressure reduces as the orifice increases:
DN2 – 0 to 6 Bar – 1.8 L/min
DN4 – 0 to 4 Bar – 6.5 L/min
DN6 – 0 to 2 Bar – 8.0 L/min
DN8 – 0 to 1 Bar – 9.0 L/min
The maximum operating pressure is reduced by approximately 20% with DC operation.
This choice of orifice allows the valve to be configured according to the required balance between flow capacity and operating pressure.
PVC or PTFE Construction
Two principal body materials are available:
PVC
A practical chemical-resistant thermoplastic widely used for acids, alkalis, water treatment chemicals and industrial dosing systems where the specific medium is compatible with PVC.
PTFE
Provides substantially broader chemical resistance for demanding applications involving aggressive acids, alkalis and other corrosive process media.
Body Material:
✓ PVC
✓ PTFE
Seal Materials:
✓ EPDM
✓ FKM
✓ PTFE
Acid & Alkali Service
The RSG 148 is particularly suited to applications where metallic wetted components are undesirable.
Typical media can include:
✓ Acids
✓ Alkalis
✓ Chemical Solutions
✓ Water Treatment Chemicals
✓ Cleaning Chemicals
✓ Dosing Fluids
✓ Corrosive Process Liquids
✓ Laboratory Process Fluids
✓ Compatible Industrial Chemicals
Chemical suitability must always be checked against the body, PTFE bellows and selected sealing materials, taking concentration, temperature and operating conditions into account.
Seal Selection
EPDM, FKM and PTFE sealing options allow the valve to be adapted to different chemical applications.
EPDM can provide good compatibility with many water-based chemicals, acids and alkalis.
FKM provides resistance to many oils, hydrocarbons and chemical media.
PTFE provides very broad chemical resistance and is particularly useful for aggressive chemical applications.
Seal selection should be based on the exact chemical, concentration and operating temperature rather than chemical type alone.
Temperature
Ambient Temperature: 0°C to +50°C
The permissible media temperature depends upon body material, operating pressure and selected elastomer rather than having one universal maximum temperature.
This is particularly important with the PVC version because allowable pressure changes with operating temperature. The manufacturer's specification therefore refers to its pressure/temperature and elastomer temperature data rather than assigning one temperature rating to every configuration.
Solenoid Coil & Electrical Specification
The Type 148 uses a DIN Form A solenoid system designed for continuous industrial operation.
Connection: DIN EN 175301-803 Form A
Duty Cycle: 100% ED
Protection: IP65 with plug fitted
Voltage Tolerance: ±10%
Mounting: Solenoid preferably upright
Coil specification 8W at 24V DC and 11VA at 230V AC, with an integrated rectifier for AC operation.
Connexion can also configure the valve with the Nass Magnet System 13/30 15W operator where required.
Voltage Options
Available coil voltages include:
✓ 12V DC
✓ 24V DC
✓ 48V DC
✓ 110V DC
✓ 220V DC
✓ 12V AC
✓ 24V AC
✓ 48V AC
✓ 110V AC
✓ 230V AC
✓ 380V AC 50/60Hz
Special voltages can also be supplied according to application requirements.
ATEX Hazardous Area Option
An explosion-protected solenoid operator is available for hazardous-area installations.
Available protection includes:
Ex mb IIC T4 Gb
Ex mb tb IIIC T130°C Db
This provides an explosion-protected solenoid solution for suitable gas and dust hazardous areas.
Explosion-protected electrical option operating pressure is reduced by approximately 20% with the Ex configuration.
Vacuum & Clean Service Options
The Type 148 manufacturer coding also provides dedicated options for:
✓ Vacuum Service
✓ Oil & Grease-Free Service
These can be useful for specialist process, laboratory and chemical-handling installations where cleanliness or low-pressure operation is required.
Optional Features & Accessories
Available options include:
✓ PVC Body
✓ PTFE Body
✓ EPDM Seals
✓ FKM Seals
✓ PTFE Sealing
✓ 12mm Solvent Socket
✓ Special Connections
✓ Vacuum Version
✓ Oil & Grease-Free Version
✓ Mounting Bracket
✓ LED DIN Connector
✓ M12 Connector
✓ Moulded Cable Connector
✓ 24V DC Power Reduction
✓ ATEX Solenoid Operator
Typical Applications
✓ Acid Dosing Systems
✓ Alkali Dosing Systems
✓ Chemical Processing
✓ Water Treatment
✓ Chemical Transfer Systems
✓ Laboratory Equipment
✓ Cleaning Systems
✓ Dosing Equipment
✓ Process Machinery
✓ Chemical Skids
✓ OEM Chemical Equipment
✓ Corrosive Fluid Control
Why Choose the RSG Type 148?
The RSG 148 provides a specialist alternative to conventional metallic solenoid valves where chemical resistance and isolation of the operating mechanism from the process fluid are important.
Its combination of PVC or PTFE construction, isolating PTFE bellows, direct acting zero-differential operation and EPDM, FKM or PTFE seal options makes it particularly useful for acid, alkali and chemical dosing applications.
With DN2 to DN8 orifices, pressures up to 6 Bar, multiple electrical configurations and options for ATEX, vacuum and oil/grease-free service, the Type 148 can be configured around a wide variety of chemical-control applications.
Available Versions
Type 148 PVC – PVC Body
Type 148 PTFE – PTFE Body
Orifice: DN2, DN4, DN6 or DN8
Connection: 1/4" BSP
PVC Option: 12mm Solvent Socket
Function: Normally Closed
Pressure: 0–6 Bar according to orifice
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