Parker 639C-4 Compression Tube Plug Brass

Product Description

The PARKER 639C-4 is a brass compression tube plug designed to seal the open end of a compression fitting or tubing line. It terminates a compression connection without requiring a threaded mate, making it useful for capping unused ports or temporarily or permanently closing off a line. Rated to 30 psi maximum working pressure, the 639C-4 is built to SAE J-512 standards and handles a wide temperature range, from -65 degrees F up to 250 degrees F. Licensed plumbers, HVAC technicians, and fluid-system mechanics install this fitting type in hydraulic, pneumatic, fuel, and refrigerant-adjacent tubing circuits.

This plug is suited for residential and light commercial applications where a reliable, leak-free compression termination is needed. Common install scenarios include capping a spare port on a manifold, decommissioning a tubing branch, or closing off a line during staged system build-out. The SAE J-512 compression end connection is the termination style, and the NPTF thread standard applies to the fitting interface. Its brass construction makes it compatible with copper and compatible soft-metal tubing commonly found in HVAC, plumbing, and fluid-distribution systems.

Key Features

• Brass construction provides corrosion resistance and durability in fluid-handling applications
• SAE J-512 compression end connection for standardized, reliable sealing
• Rated to 30 psi maximum working pressure
• Wide operating temperature range: -65 degrees F to 250 degrees F
• NPTF thread standard for leak-resistant thread engagement
• Sold individually; no special tooling required beyond standard compression fitting tools

Compatibility

Designed as an OEM-style compression tube plug conforming to SAE J-512, suitable for use in compression tubing systems requiring a standard brass plug termination.

Installation Notes

Installation should be performed by a licensed plumber, HVAC technician, or qualified fluid-systems mechanic. Before installing, shut off and depressurize the system completely and verify there is no residual fluid pressure in the line. Use appropriate compression fitting tools to seat the ferrule and plug without over-tightening, which can deform the ferrule and cause leaks. Follow applicable codes including IPC or IFGC as relevant to the system type.