B K Mueller 521-702HN Black Union 3/8 in Brass Iron 5 Pack

Product Description

The B K Mueller Industries 521-702HN is a 3/8-inch black union fitting constructed from brass and iron. Unions allow a pipe section to be disconnected and reconnected without disturbing the surrounding piping, making them a standard component in gas and plumbing distribution systems. This fitting ships in a package of five units, making it a practical choice for contractors stocking jobsite inventory or servicing multiple connections in a single visit. The black finish is typical of gas-service fittings used in residential and light commercial applications.

This union is suited for use in low-pressure gas piping, black iron pipe distribution systems, and similar applications where a removable threaded connection is required. Plumbers and gas fitters install these fittings during appliance rough-in, service disconnects, and system modifications. The 3/8-inch size is common at appliance drops and branch connections serving furnaces, water heaters, dryers, and similar equipment.

Key Features

• 3/8-inch fitting size for standard branch and appliance connections
• Black finish consistent with gas-service piping conventions
• Brass and iron construction for durability in threaded pipe systems
• Removable union design allows service disconnect without cutting pipe
• Packaged in quantities of five for multi-connection jobs

Compatibility

Designed as an OEM-style replacement or service fitting for standard 3/8-inch threaded black iron pipe systems in residential and light commercial gas or plumbing applications.

Installation Notes

Installation should be performed by a licensed plumber or gas fitter in accordance with applicable codes including the IFGC and local amendments. Shut off the gas supply and verify zero pressure at the line before disassembling or installing any union fitting. Apply appropriate thread sealant rated for gas service to all male threads before assembly. Do not over-tighten; follow standard trade practice for threaded iron fittings and leak-test all connections after installation.

WARNING: This product can expose you to chemicals including lead, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.