Parker 6-4 Hlo-s Compression Tube Union Orfs Steel

Product Description

The PARKER 6-4 HLO-S is a compression tube union with O-Ring Face Seal (ORFS) end connections, manufactured from steel for use in high-pressure hydraulic and fluid power systems. It connects two tube lines of differing outside diameters — 3/8 inch and 1/4 inch — using a compression fitting design with UNF thread standard. Rated to a maximum working pressure of 9200 psi, this union is built for demanding service environments where leak-free performance is critical. Hydraulic technicians and fluid power specialists specify this fitting when reducing or joining tube runs in tight plumbing assemblies.

This union is used in hydraulic systems, mobile equipment, and industrial fluid power applications where ORFS connections are specified for reliable, vibration-resistant sealing. The dual-diameter tube connection makes it suitable for installations requiring a transition between 3/8 inch and 1/4 inch tubing within the same line. Typical install scenarios include machine tool plumbing, off-highway equipment, and industrial hydraulic circuits where tube unions must hold pressure without weeping.

Key Features

• ORFS end connections provide a leak-free metal-to-metal seat with O-ring backup for high-pressure reliability
• Maximum working pressure rated at 9200 psi for demanding hydraulic service
• Connects 3/8 inch and 1/4 inch outside diameter tubing in a single union body
• UNF thread standard ensures compatibility with standard hydraulic fittings and adapters
• Steel construction offers strength and durability in high-pressure fluid power circuits

Compatibility

Designed as an OEM-style replacement or service fitting for hydraulic and fluid power tube assemblies using O-Ring Face Seal connections with UNF threading. Verify tube outside diameter and working pressure requirements before installation.

Installation Notes

Installation should be performed by a qualified hydraulic technician or fluid power specialist. Depressurize and drain the hydraulic circuit completely before disassembly or fitting replacement. Inspect the O-ring seating surface for nicks or contamination prior to assembly, and ensure the O-ring is properly seated to achieve a reliable seal. Consult applicable industry standards and equipment service documentation for proper assembly procedures.