B K/mueller Inds(import) 521-003HC Black Cross Fitting

Product Description

The B K/MUELLER INDS(IMPORT) 521-003HC is a 1/2-inch black malleable iron cross pipe fitting used to join four sections of pipe at a single junction point. This four-way fitting is a standard component in low-pressure piping systems, including gas distribution, compressed air lines, and black iron plumbing runs. Its threaded ends accept standard NPT pipe connections, making it compatible with conventional threaded pipe assemblies. Licensed plumbers and pipefitters install this fitting during new construction and retrofit work where a branch connection is needed in multiple directions from one central point.

This cross fitting is suited for residential and light commercial piping applications where black iron pipe is the specified material. Common install scenarios include natural gas supply lines, propane distribution headers, and workshop air distribution systems. The 1/2-inch size is frequently used for branch feeds off a main trunk line. The package quantity of 45 units makes this SKU appropriate for contractors stocking out a job or maintaining shop inventory.

Key Features

• 1/2-inch four-way cross configuration for multi-directional pipe branch connections
• Black iron malleable construction suited for gas and air service
• Threaded NPT ends for standard pipe assembly without special tooling
• Sold in a package quantity of 45 units for job-lot or inventory stocking

Compatibility

Designed as an OEM-style replacement and standard-service fitting for 1/2-inch black iron threaded pipe systems in residential and light commercial gas, air, and fluid distribution applications.

Installation Notes

Installation is performed by a licensed plumber or pipefitter following applicable local codes and IFGC requirements for gas piping systems. Shut off the gas supply or depressurize the air line completely before disassembling existing connections. Apply an approved thread sealant or PTFE tape rated for the service medium to all threaded joints before assembly. Do not over-torque the fitting, as malleable iron threads can crack under excessive force.