Parker 4 Hlo-s Tube Union O-ring Face Seal 1/4 in 9200 Psi

Product Description

The PARKER 4 HLO-S is a compression tube union with an O-Ring Face Seal (ORFS) end connection, designed for high-pressure hydraulic and fluid power lines. Constructed from steel, this union joins two tube ends of equal outside diameter in a straight-run configuration. The ORFS design provides a leak-free metal-to-metal seat combined with an O-ring seal, making it well suited for systems where vibration, pressure spikes, or fluid compatibility are concerns. It accepts 1/4-inch outside diameter tubing and is rated to a maximum working pressure of 9200 psi. The UNF thread standard ensures compatibility with standard SAE ORFS fittings used across hydraulic systems.

This union is used in mobile hydraulic equipment, industrial fluid power systems, and high-pressure plumbing circuits where a reliable inline tube connection is required. Typical applications include construction equipment hydraulics, agricultural machinery, and industrial presses where tube routing requires a straight union junction. It is installed by hydraulic technicians and fluid power specialists working on both OEM builds and field service repairs.

Key Features

• O-Ring Face Seal (ORFS) end connections for leak-free performance under high pressure
• Maximum working pressure of 9200 psi for demanding hydraulic applications
• Steel construction provides durability in industrial and mobile equipment environments
• UNF thread standard ensures broad compatibility with SAE ORFS hardware
• Accepts 1/4-inch outside diameter tubing
• Overall length of 1.08 inches for compact inline installation

Compatibility

Designed as an OEM-style replacement or new-installation fitting for hydraulic and fluid power systems using 1/4-inch OD tubing with SAE O-Ring Face Seal connections and UNF thread standard.

Installation Notes

Installation should be performed by a qualified hydraulic technician. Depressurize and bleed the hydraulic system completely before disconnecting any lines or fittings. Inspect the O-ring seating surface for nicks or contamination before assembly, and ensure the O-ring is properly seated and lubricated with a compatible fluid prior to torquing. Follow the equipment manufacturer's torque specifications and applicable fluid power system standards during final assembly.