PFA Straight Union Reducer

PFA straight union reducer is a fluoropolymer tube fitting designed to connect two PFA tubes with different outside diameters in a straight fluid line.

The reducer uses a flared tube connection to create a clean, reliable joint without adhesives. It is suitable for chemical delivery, semiconductor wet-process equipment, high-purity fluid handling and industrial systems where corrosion resistance, cleanliness and temperature performance are important.

The fitting body is manufactured from PFA and is designed for use with compatible flared fluoropolymer tubing. Equal-size straight unions and reducing-size configurations are available.

Standard reducing combinations include tube outside diameters from 1/4 inch to 1-1/2 inches, with custom configurations available according to system requirements.

Key Features

• Connects two different tube outside diameters
• PFA construction for corrosive fluid service
• Flared connection without adhesive
• Smooth internal flow path
• Low moisture absorption
• Suitable for high-purity fluid systems
• Resistant to many acids, alkalis and process chemicals
• Straight compact configuration
• Easy installation and replacement
• Equal and reducing sizes available
• Compatible tube assemblies available
• Custom size combinations can be evaluated

Product Structure

The fitting consists of:

• PFA fitting body
• Large tube connection end
• Small tube connection end
• Flared sealing interface
• Compression nut or compatible locking structure

The tube end is flared and secured to the fitting to form the connection.

Final fitting construction may vary according to tube size and application requirements.

Standard Dimensions

Large Tube O.D.	Small Tube O.D.	Orifice	A	B	C	Hex
3/8 in	1/4 in	3.81 mm	69.09 mm	32.26 mm	29.46 mm	17.46 mm
1/2 in	1/4 in	3.81 mm	71.63 mm	34.54 mm	29.46 mm	23.81 mm
1/2 in	3/8 in	6.35 mm	74.17 mm	34.54 mm	32.26 mm	23.81 mm
3/4 in	1/4 in	3.81 mm	75.18 mm	38.61 mm	29.46 mm	30.16 mm
3/4 in	3/8 in	6.35 mm	77.98 mm	38.61 mm	32.26 mm	30.16 mm
3/4 in	1/2 in	9.65 mm	80.52 mm	38.61 mm	34.54 mm	30.16 mm
1 in	1/2 in	9.65 mm	85.85 mm	43.94 mm	34.54 mm	36.51 mm
1 in	3/4 in	16.76 mm	89.66 mm	43.94 mm	38.61 mm	36.51 mm
1-1/4 in	3/4 in	16.76 mm	97.00 mm	45.70 mm	38.61 mm	49.80 mm
1-1/4 in	1 in	22.35 mm	104.00 mm	45.70 mm	43.94 mm	49.80 mm
1-1/2 in	1/2 in	9.65 mm	103.00 mm	49.00 mm	32.26 mm	67.60 mm
1-1/2 in	3/4 in	16.76 mm	106.00 mm	49.00 mm	38.61 mm	67.60 mm
1-1/2 in	1 in	23.35 mm	114.00 mm	49.00 mm	43.94 mm	67.60 mm
1-1/2 in	1-1/4 in	27.94 mm	122.00 mm	49.00 mm	45.70 mm	67.60 mm

Dimensional note: The table is for reference. Final dimensions and tolerances should be confirmed using the approved production drawing.

Available Size Combinations

Equal Straight Unions

• 1/4 in × 1/4 in
• 3/8 in × 3/8 in
• 1/2 in × 1/2 in
• 3/4 in × 3/4 in
• 1 in × 1 in

Straight Union Reducers

• 1/4 in × 3/8 in
• 1/4 in × 1/2 in
• 3/8 in × 1/2 in
• 3/8 in × 3/4 in
• 1/2 in × 3/4 in
• 1/2 in × 1 in
• 3/4 in × 1 in
• Additional sizes subject to evaluation

For website presentation, it is better to show dimensions in the order:

Large Tube O.D. × Small Tube O.D.

Example:

1/2 in × 1/4 in PFA Straight Union Reducer

Typical Applications

Semiconductor Equipment

Suitable for chemical delivery and high-purity fluid lines in:

• Wet-process systems
• Chemical cabinets
• Wafer-cleaning equipment
• Chemical distribution units
• Process tool connections

Chemical Processing

Used for transferring selected:

• Acids
• Alkalis
• Solvents
• Cleaning chemicals
• Corrosive process liquids

Pharmaceutical and Laboratory Systems

Suitable for selected analytical, dosing and process-fluid installations requiring clean, corrosion-resistant connections.

Water Treatment

Can be used in ultrapure water, chemical dosing and filtration equipment.

Industrial Fluid Handling

Suitable for pumps, valves, instruments and process equipment requiring transition between different tube sizes.

Material Advantages

Chemical Resistance

PFA provides excellent resistance to many corrosive chemicals. Compatibility must be confirmed according to the exact medium, concentration, temperature and exposure time.

High Purity

The smooth PFA surface and low moisture absorption make the fitting suitable for demanding clean-fluid systems, subject to material grade and cleanliness requirements.

Temperature Performance

PFA can operate over a broad temperature range, but the allowable fitting temperature and pressure depend on:

• Tube size
• Connection structure
• Operating medium
• Working pressure
• Thermal cycling
• Installation conditions

Smooth Flow Path

The reducer is designed to provide a controlled transition between different tube diameters, helping reduce abrupt flow disturbance.

Installation Guidance

1. Cut the tube end square and cleanly.
2. Ensure the tube surface is free from contamination.
3. Flare the tube using suitable tooling.
4. Insert the fitting into the flared tube end.
5. Tighten the nut using the recommended method.
6. Avoid excessive tightening.
7. Perform a leakage or pressure test after installation.

For semiconductor or high-purity applications, use clean tools, gloves and suitable packaging procedures.