3/4" PTFE Solenoid Valve for Chemical Dosing – UDC20TF
The UDC20TF is a 3/4" 2/2 way normally closed PTFE solenoid valve designed for controlling strong acids, strong alkalis and highly corrosive chemical fluids.
Featuring a PTFE valve body, PTFE sealing system and isolated dry-armature construction, the UDC20TF provides excellent resistance to aggressive chemicals.
The manufacturer specifies the PTFE UDC-TF body with corrosion resistance across approximately pH 0–14, making it the preferred version for applications where PVC may not provide sufficient chemical resistance.
The zero-pressure assisted-lift design operates from 0 Bar without requiring a minimum pressure differential. The larger UDC20TF incorporates a 13mm orifice providing 66.7 L/min water flow at 1 Bar pressure drop, with an operating pressure range of 0 to 0.5 Bar.
Valve Function & Operation
Function: 2/2 way normally closed
Operation: Assisted lift
Design: Isolated dry armature
Normal Position: Closed when de-energised
Energised Position: Open
Minimum Differential Pressure: 0 Bar
The UDC-TF family is specified as a normally closed, dry-armature assisted-lift design operating from zero differential pressure.
This allows the UDC20TF to operate in low-pressure and gravity-fed chemical systems where conventional pilot-operated solenoid valves requiring a minimum differential pressure may be unsuitable.
Ports & Connections
Port Size: 3/4" BSP
Optional Thread: NPT
The 3/4" connection combined with the larger 13mm internal orifice provides greater flow capacity than the smaller UDC-TF models, making the UDC20TF suitable for higher-flow chemical dosing and transfer applications.
Pressure & Performance
Operating Pressure: 0 to 0.5 Bar
Minimum Differential Pressure: 0 Bar
Orifice: 13mm
Water Flow: 66.7 L/min at 1 Bar pressure drop
Maximum Media Viscosity: 20 cSt
Vacuum: Not suitable
Construction & Materials
Body: PTFE
Seals: PTFE
Diaphragm: NBR with PTFE coating
Solenoid Tube: Stainless steel
Armature: 430F stainless steel
Shading Ring: Copper
Coil Housing: Resin or metal
The manufacturer specifies the PTFE-bodied UDC-TF range with approximately pH 0–14 corrosion resistance, compared with approximately pH 3–11 for the PVC-bodied UDC range.
Chemical & Media Compatibility
Suitable for compatible:
✓ Strong acids
✓ Strong alkalis
✓ Hydrochloric acid (HCl)
✓ Sulphuric acid (H₂SO₄)
✓ Chemical dosing fluids
✓ Water-treatment chemicals
✓ Corrosive process liquids
✓ Compatible gases
PTFE provides very broad chemical resistance, but compatibility should be confirmed for the complete wetted construction against the actual chemical, concentration and operating temperature.
Temperature
Media Temperature: -5°C to +80°C
Ambient Temperature: -10°C to +40°C
Maximum Media Viscosity: 20 cSt
Coil & Electrical
Coil Type: XL
Coil Power: 28 Watt
Insulation: Class F 155°C
Duty Rating: 80%
Protection: IP54
Electrical Connection: 30cm flying leads
AC Maximum ON Time: 2 hours
AC Minimum Cooling Time: 30 minutes
DC Maximum ON Time: 30 minutes
DC Minimum Cooling Time: 7.5 minutes
The manufacturer specifies an 80% duty rating with a maximum AC ON period of 2 hours and maximum DC ON period of 30 minutes before the required cooling interval.
Voltage Options
12V DC
24V DC
24V AC
110V AC
230V AC
AC versions are available for 50 or 60Hz operation.
Typical Applications
✓ Concentrated acid dosing
✓ Strong alkali dosing
✓ Chemical dosing systems
✓ Chemical transfer equipment
✓ Water treatment systems
✓ Chemical processing plants
✓ Corrosive process control
✓ OEM chemical equipment
Why Choose the UDC20TF?
The UDC20TF combines a highly corrosion-resistant PTFE body and sealing system with isolated dry-armature construction, true zero-pressure operation and increased flow capacity.
Its 13mm orifice provides 66.7 L/min water flow at 1 Bar pressure drop, while the PTFE body provides approximately pH 0–14 corrosion resistance. This makes the UDC20TF particularly suitable for aggressive chemicals where both high chemical resistance and a larger flow path are required.
For less aggressive chemical applications within the compatibility range of PVC, the equivalent PVC-bodied UDC20 provides a lower-cost alternative.
