Eaton 661X4 Compression Tube Connector 1/8 Inch Fnpt

Product Description

The EATON 661X4 is a straight compression tube connector designed for joining tubing to female NPT threaded ports in fluid and pneumatic systems. It features a compression inlet on one end and a 1/8 inch FNPT threaded connection on the other, providing a leak-resistant mechanical seal without soldering or brazing. Constructed from brass, it is rated for a maximum working pressure of 2000 psi and operates across a wide temperature range down to -65 degrees F. Licensed trades including plumbers, HVAC technicians, and instrumentation specialists use this fitting in control tubing runs, instrument lines, and low-volume fluid circuits where reliable sealing at small diameters is required.

This fitting suits residential and light commercial applications where 1/8 inch FNPT ports are present, such as pressure sensing lines, pneumatic control circuits, and refrigeration instrument connections. Its compact straight profile at 0.925 inches overall length allows installation in tight spaces. It is sold individually and is appropriate wherever a durable, pressure-rated compression-to-female-NPT transition is needed in a brass-compatible system.

Key Features

• Straight compression-to-FNPT configuration allows direct connection from tubing to threaded female ports
• Brass construction provides corrosion resistance and compatibility with a wide range of fluids and gases
• 2000 psi maximum working pressure supports demanding instrument and control line service
• Rated to -65 degrees F minimum temperature for low-temperature service environments
• NPTF thread standard ensures pressure-tight engagement with standard NPT female ports
• Compact 0.925 inch overall length suits confined installation areas

Compatibility

Designed as an OEM-style replacement or new-installation fitting for systems requiring a 1/8 inch compression-to-FNPT straight connector in brass with NPTF thread standard.

Installation Notes

Installation should be performed by a licensed plumber, HVAC technician, or qualified instrumentation mechanic. Depressurize and isolate the system completely before removing or installing any compression fitting. Hand-tighten the compression nut first, then follow the fitting manufacturer's standard procedure for the tubing material being used. Verify all connections are leak-free under system pressure before returning the circuit to service.