Brasscraft 66-4-4X Tube Adapter 1/4 in Compression X Fnpt

Product Description

The BRASSCRAFT 66-4-4X is a brass tube adapter designed to connect 1/4-inch compression tubing to a female NPT threaded fitting. This fitting is a standard transition piece used in plumbing, HVAC, and refrigeration systems where a compression line must terminate into a threaded port. The all-brass construction provides corrosion resistance and durability in both wet and pressurized service environments. Licensed plumbers and HVAC technicians install this adapter when transitioning between tubing runs and threaded components such as valves, manifolds, and equipment ports.

This adapter is suited for residential and light commercial applications involving copper or compatible soft tubing lines. Typical install scenarios include refrigerant-side plumbing connections, water supply lines to appliances, and instrument tubing hookups where a leak-free mechanical seal is required without soldering. The compression-by-FNPT configuration makes it a practical choice in tight spaces where torch work is restricted or undesirable.

Key Features

• 1/4-inch compression inlet to female NPT outlet transition
• All-brass construction for corrosion resistance in plumbing and HVAC service
• Domestically manufactured fitting
• Compression end eliminates the need for soldering at the tube connection
• Female NPT thread accepts standard male NPT fittings and equipment ports

Compatibility

Designed as an OEM-style replacement or standard-service fitting for residential and light commercial plumbing and HVAC systems requiring a 1/4-inch compression to female NPT adapter.

Installation Notes

This fitting is installed by licensed plumbers or HVAC technicians following applicable IPC or IFGC guidelines for the system type. Shut off the water or refrigerant supply and relieve system pressure before making any connections. Hand-tighten the compression nut onto the tubing and follow with wrench tightening per standard compression fitting practice — do not overtighten, as brass compression fittings can crack or deform with excessive force. Apply thread sealant or PTFE tape to the male NPT threads being inserted into the FNPT end before final assembly.

Technical Specifications

• Connection Type: Compression x FNPT
• Size: 1/4 inch
• Material: Brass
• Origin: Domestic

Standard Information

• Brand: BRASSCRAFT
• Manufacturer Part Number: 66-4-4X