Midland Industries LF39-4 Flare Plug 1/4 in 45 Deg Brass

Product Description

The MIDLAND INDUSTRIES LF39-4 is a lead-free brass flare plug designed to cap or seal 45-degree flared tubing connections in refrigeration, HVAC, and plumbing systems. It threads onto a 7/16-20 flare fitting to terminate a line or block a port during service or installation. Constructed from lead-free brass, this plug meets material requirements for potable water and refrigerant applications. Its rated operating range spans -40 to 250 degrees F, making it suitable for both low-temperature refrigerant lines and hot-water plumbing circuits. Plumbers, HVAC technicians, and refrigeration mechanics typically carry this fitting as a standard service component.

This plug is intended for use with aluminum, brass, copper, or steel tubing in 45-degree flare configurations. Common applications include capping unused ports on manifolds, sealing service valves during pressure testing, and terminating branch lines in refrigeration or hydronic systems. The 1/4-inch connection size fits standard quarter-inch flare tubing commonly found in residential and light commercial HVAC and refrigeration equipment.

Key Features

• Lead-free brass construction for compliance with low-lead material requirements
• 45-degree flare connection type for a leak-resistant mechanical seal
• 7/16-20 thread for standard quarter-inch flare fittings
• Compatible with aluminum, brass, copper, and steel tubing
• Rated from -40 to 250 degrees F for broad application coverage
• Lightweight at 0.018 pounds for easy field carry and inventory

Compatibility

Designed for use with aluminum, brass, copper, or steel tubing in 45-degree flare systems with a 1/4-inch connection size and 7/16-20 thread.

Installation Notes

This fitting is typically installed by licensed plumbers or HVAC technicians. Depressurize and isolate the line before removing or installing any flare fitting. Hand-tighten first, then use a flare nut wrench to snug the connection without overtightening, which can crack the flare seat. Verify the mating flare is properly formed and free of burrs before seating the plug.