Legris 3666 04 08 Push-in Reducer Fitting 435 Psi

Product Description

The LEGRIS 3666 04 08 is a push-to-connect plug-in reducer fitting designed for tube-to-stem connections in pneumatic and fluid handling systems. Constructed from nickel-plated brass, it reduces between a 4 mm and 8 mm outside diameter tube in a single inline connection. The fitting holds a maximum working pressure of 435 psi and operates across a wide temperature range, from -4 degrees F up to 302 degrees F. The FKM o-ring seal provides reliable performance with both liquid and gas media. Installation requires no tools beyond hand pressure to seat the tubing — a standard push-in mechanism locks the line securely. This fitting is used by mechanical contractors, pneumatic system technicians, and industrial maintenance trades.

This reducer fitting is suited for inline pneumatic circuits, instrumentation tubing runs, and light fluid distribution systems where a tube outside diameter reduction from 8 mm to 4 mm is needed at a stem connection point. It is compatible with liquid and gas service, making it applicable in compressed air lines, process gas distribution, and low-pressure hydraulic instrumentation circuits. The compact form factor and short overall length of 1.4 inches allow installation in tight panel or manifold spaces where a standard union reducer would not fit.

Key Features

• Push-to-connect design — no tools required for tube insertion
• Reduces 8 mm OD tube to 4 mm OD tube in a single fitting body
• Nickel-plated brass construction for corrosion resistance in air and gas service
• FKM o-ring seal rated for liquid and gas media
• Wide temperature range: -4 degrees F to 302 degrees F
• Compliant with RoHS, REACH, ATEX, PED, ISO 14743, and FDA 21CFR standards

Compatibility

Designed as a push-to-connect reducer for pneumatic and fluid lines using 4 mm and 8 mm outside diameter tubing in tube-to-stem fitting applications.

Installation Notes

Installation is performed by pneumatic system technicians or mechanical contractors. Depressurize and isolate the line completely before removing any existing fitting. Cut tubing squarely and deburr the end before insertion to ensure a proper seal. Verify tube outside diameter matches the fitting before seating — do not force mismatched tubing into the collet.