Midland Industries 18080 Reducing Union 3/8x5/16 Compression

Product Description

The MIDLAND INDUSTRIES 18080 is a brass reducing union designed to connect two different tube sizes using compression fittings on both ends. The larger end accepts 3/8 inch compression connections and the smaller end accepts 5/16 inch compression connections, allowing a straight inline transition between mismatched tubing diameters. Rated to 200 psi and serviceable across a temperature range of -65 to 250 degrees F, this fitting suits demanding plumbing, HVAC, and refrigeration applications. Plumbers, HVAC technicians, and gas service professionals install this type of fitting when tube sizing changes within a run. The hex dimension measures 0.56 inches and the center-to-center length is 0.94 inches.

This reducing union is intended for use with copper, aluminum, and thermoplastic tubing. It is a common choice in residential and light commercial service work where a tube diameter change must be made without soldering or specialized tools. Typical install scenarios include fuel gas supply lines, refrigerant line sets where code permits compression connections, and potable or process water systems that require a quick, reliable inline reducer.

Key Features

• Reduces 3/8 inch compression to 5/16 inch compression in a single inline fitting
• Rated to 200 psi working pressure
• Operating temperature range of -65 to 250 degrees F
• Compatible with copper, aluminum, and thermoplastic tubing
• 9/16-24 thread specification with 0.56 inch hex for standard wrench engagement
• Brass construction for corrosion resistance and long service life

Compatibility

Designed for use with copper, aluminum, and thermoplastic tubing. Suitable as an OEM-style compression reducing union in residential and light commercial plumbing, HVAC, and refrigeration tubing systems.

Installation Notes

Installation is performed by licensed plumbers or HVAC technicians in accordance with applicable local codes and IPC or IFGC requirements. Shut off and depressurize the supply line fully before disassembling or installing any compression fitting. Use two wrenches when tightening to avoid twisting the tubing, and verify that tubing ends are cut square and deburred before seating the compression ferrule. Do not overtighten compression nuts, as this can deform the ferrule and cause leaks.