Parker A4BU4-MG Bulkhead Union Fitting 1/4 Inch Od

Product Description

The PARKER A4BU4-MG is a push-to-connect bulkhead union tube fitting designed for tube-to-tube connections through a panel or wall. Constructed from polyoxymethylene (POM), a rigid engineering-grade thermoplastic, this fitting delivers a rated working pressure of 300 psi. The tan-colored body accepts 1/4-inch outside diameter tubing on both sides, providing a secure, tool-free connection. It is sized for compact installations where a straight-through union must pass through a bulkhead, partition, or enclosure wall. HVAC technicians, plumbers, and equipment service professionals use this type of fitting in instrument tubing runs, control line assemblies, and fluid transfer systems where a leak-free panel pass-through is required.

This fitting is suited for residential and light commercial applications involving pneumatic control lines, instrument air, water, and compatible fluid systems. The push-to-connect design allows tubing to be inserted and locked without additional tools, making it practical in tight or awkward installation locations. It is appropriate wherever a through-panel tube union is needed and the system fluid and pressure conditions are compatible with POM construction and a 300 psi pressure rating.

Key Features

• Push-to-connect design accepts 1/4-inch OD tubing on both ends with no tools required
• Polyoxymethylene (POM) body offers rigidity and chemical resistance suitable for instrument and fluid service
• Rated for 300 psi working pressure
• Bulkhead configuration allows tube-to-tube pass-through mounting in panels or enclosures
• Tan body color aids visual identification in multi-line installations

Compatibility

Designed as an OEM-style push-to-connect bulkhead union for use with 1/4-inch outside diameter tubing in pneumatic, instrument, and fluid transfer systems compatible with POM fitting materials and a 300 psi pressure rating.

Installation Notes

Installation should be performed by a qualified technician familiar with pneumatic or fluid piping systems. Depressurize and drain the system completely before removing or installing any fitting. Verify that the tubing material, fluid media, and operating temperature are compatible with POM construction before installation. Tubing should be cut cleanly and squarely, deburred, and inserted fully until it seats to ensure a leak-free connection.