Midland Industries 18171LF 3/8 Compression X 1/2 Sweat Adapter

Product Description

The MIDLAND INDUSTRIES 18171LF is a lead-free brass adapter fitting designed to transition a 3/8-inch compression connection to a 1/2-inch sweat (solder) connection. This type of fitting is commonly installed in potable water supply lines, hydronic systems, and refrigeration tubing runs where a mechanical compression end meets a copper sweat joint. The lead-free brass construction meets modern plumbing code requirements for drinking water applications. Thread dimensions are 9/16-24 on the compression side and 1/2-14 on the sweat side. Licensed plumbers and HVAC technicians are the primary installers of this fitting in both residential and light commercial settings.

The 18171LF adapter is suited for use with copper, aluminum, or plastic tubing on the compression side, making it a versatile transition fitting in mixed-material piping systems. Typical applications include connecting supply lines to fixtures, appliances, or equipment where a compression fitting meets an existing sweat-connected copper line. The fitting is rated for temperatures ranging from -40 degrees F to 250 degrees F, covering most standard hot and cold water and low-pressure hydronic applications.

Key Features

• Lead-free brass construction meets current potable water codes
• 3/8-inch compression inlet x 1/2-inch sweat outlet transition
• Thread specification: 9/16-24 compression x 1/2-14 sweat
• Compatible with copper, aluminum, or plastic tubing on the compression side
• Rated -40 degrees F to 250 degrees F operating temperature range
• Compact profile: 1.15 inches height, 0.7 inches width and length

Compatibility

Designed for use with copper, aluminum, or plastic tubing on the compression side, transitioning to a 1/2-inch sweat copper connection. Suitable for lead-free compliant plumbing systems in residential and light commercial installations.

Installation Notes

Installation should be performed by a licensed plumber or qualified HVAC technician in accordance with applicable local plumbing codes and the IPC. Shut off the water supply and relieve system pressure before beginning work. The sweat end requires standard soldering technique with lead-free solder on the copper connection; the compression end should be hand-tightened then snugged with a wrench - do not overtighten, as brass compression fittings can crack under excessive torque. Inspect both connections for leaks after restoring pressure.