3/8 in. x 1/4 in. Compression Adapter, Tube to Female NPT
Overview
The Champion Brass 66A-6B is a brass compression-to-female-pipe adapter that lands 3/8 in. compression tubing onto a 1/4 in. FPT (female NPT) connection. It accepts copper, aluminum, and thermoplastic tubing and seals on the ferrule, so no soldering or flaring is needed to connect a tube line to a male-threaded fitting, valve, or pump nipple.
Technical Specifications
| Part Number (MPN) | 66A-6B |
| Fitting Type | Female Adapter (Tube to FPT) |
| Connection 1 | 3/8 in. Compression |
| Connection 2 | 1/4 in. Female NPT (FPT) |
| Thread Size | 9/16-24 x 1/4-18 |
| Hex Size | 0.68 in. |
| Pressure Rating | 200 psi |
| Temperature Rating | -65°F to 250°F |
| For Use With | Copper, aluminum, and thermoplastic tubing |
Materials of Construction
| Body | Brass |
| Sleeve / Ferrule | Brass |
Typical Applications
Use the 66A-6B to connect 3/8 in. tubing to a 1/4 in. male NPT nipple on metering pumps, injection quills, calibration columns, and inline accessories in water treatment, cooling tower, and boiler chemical-feed systems where a female-pipe termination is required.
Cross-Reference and Interchange
We did not find published competitor cross-references for this exact part. Replacing another brand's 3/8 in. compression x 1/4 in. FPT adapter? Send us your part number and we will confirm the interchange by matching nominal size, connections, and rating.
Sizing and Installation Resources
- Compression Fitting Sizing Chart
- NPT Thread Tightening: Turns Past Hand Tight
- Teflon Tape vs. Pipe Dope
- Metering Pump Chemical Compatibility Chart
- Chemical Compatibility Chart for Fluid Handling
Frequently Asked Questions
Which end is the tube?
The 3/8 in. compression end takes the tube; the 1/4 in. FPT end accepts a male NPT thread.
What tubing can I use?
Copper, aluminum, and thermoplastic tubing at 3/8 in. OD.
Do I seal the threads?
Apply PTFE tape or pipe dope to the male NPT thread entering the FPT side; never on the compression ferrule.
What pressure can it hold?
Rated to 200 psi; keep within your tubing and system limits.
⚠ WARNING: This product can expose you to chemicals including lead, which is known to the State of California to cause cancer and reproductive harm. For more information go to www.P65Warnings.ca.gov.