Parker A6EU5-MG Push-to-connect Union Fitting 3/8x5/16

Product Description

The PARKER A6EU5-MG is a push-to-connect union tube fitting designed to join two tubes of different outside diameters — 3/8 inch and 5/16 inch — without tools or threaded connections. Constructed from polyoxymethylene (POM), a rigid engineering-grade thermoplastic, this fitting delivers reliable sealing performance rated to 300 psi. The push-to-connect mechanism allows technicians to make fast, repeatable tube connections during installation or system repair. It is suited for plumbing, pneumatic, and fluid-handling applications where dissimilar tube sizes must be joined inline. HVAC, refrigeration, and pneumatic control technicians commonly install this type of fitting in low-to-medium pressure tube runs.

This union fitting is used in residential and light commercial applications involving 3/8 inch and 5/16 inch OD tubing. It is appropriate for pneumatic control lines, fluid distribution systems, and instrumentation tubing where a secure, leak-free inline connection is required. The push-to-connect design eliminates the need for compression sleeves, ferrules, or wrenches, making it practical for tight spaces and quick-turnaround service calls. Installers working on HVAC control circuits, pneumatic actuators, or similar tube-based systems will find this fitting well-suited to those environments.

Key Features

• Joins 3/8 inch OD and 5/16 inch OD tubing in a single inline union
• 300 psi rated working pressure
• Polyoxymethylene (POM) construction for chemical resistance and dimensional stability
• Tool-free push-to-connect installation — no ferrules or compression sleeves required
• Tan color for visual identification in multi-line systems

Compatibility

Designed as an OEM-style push-to-connect union fitting compatible with 3/8 inch and 5/16 inch OD tubing in pneumatic, fluid, and light-pressure instrumentation systems.

Installation Notes

Installation is performed by licensed HVAC technicians, plumbers, or pneumatic system technicians. Before installing or replacing this fitting, depressurize and isolate the tube run completely. Ensure tube ends are cut cleanly and squarely with a proper tube cutter — ragged or angled cuts will compromise the push-to-connect seal. Verify tube OD matches the fitting port size before insertion; do not force mismatched tubing into the fitting body.