Midland Industries 266X4X4 Brass Female Adapter Fitting

Product Description

The MIDLAND INDUSTRIES 266X4X4 is a brass female adapter fitting that connects 1/4 inch compression tubing to a 1/4 inch female NPTF threaded port. It is designed for use in fluid and gas distribution systems where a reliable, leak-resistant transition between compression and NPTF threads is required. The fitting is rated to 300 psi and handles temperatures from -65 to 250 degrees F. Thread dimensions are 7/16-24 on the compression side and 1/4-18 NPTF on the female port. Licensed plumbers, HVAC technicians, and refrigeration mechanics install this fitting in both residential and light commercial applications.

This fitting is suited for installations involving copper, aluminum, or thermoplastic tubing where a compression-to-female NPTF connection is needed. Common applications include refrigeration line sets, pneumatic control tubing, fuel systems, and instrument air lines. The all-brass construction resists corrosion and holds up in environments with moderate vibration or thermal cycling. The 0.68 inch hex size accommodates standard open-end or adjustable wrenches for secure installation without overtightening.

Key Features

• 1/4 inch compression inlet connects to copper, aluminum, and thermoplastic tubing
• 1/4 inch female NPTF outlet provides a pressure-tight threaded seal
• Rated to 300 psi working pressure
• Operating temperature range of -65 to 250 degrees F
• 0.68 inch hex for wrench access during installation
• Brass construction for corrosion resistance and durability

Compatibility

Compatible with copper, aluminum, and thermoplastic tubing at 1/4 inch compression size. Threads are 7/16-24 compression and 1/4-18 NPTF.

Installation Notes

Installation should be performed by a licensed plumber or qualified mechanical technician following applicable IPC and IFGC guidelines. Shut off system pressure and bleed the line before removing or installing any fitting. Use a calibrated torque wrench or follow manufacturer torque guidance when tightening NPTF connections - do not overtighten, as brass threads can gall or crack under excessive force. Inspect compression ferrules for seating and deformation after tightening to confirm a leak-free connection before returning the system to service.