B K/mueller Inds(import) 521-224HC Black Merchant Coupling

Product Description

The B K/MUELLER INDS(IMPORT) 521-224HC is a 3/4-inch black merchant coupling designed for joining threaded pipe sections in plumbing, gas distribution, and mechanical piping systems. Black iron merchant couplings are a standard fitting for low-pressure gas lines, water distribution, and general industrial piping where malleable or black iron construction is appropriate. This fitting ships in a package quantity of 80 units, making it practical for contractors and supply houses stocking for ongoing installation work. Licensed plumbers and pipefitters are the primary installers for this type of fitting.

This black merchant coupling is suited for residential and light commercial applications where threaded black iron pipe connections are required. Common installation scenarios include natural gas and propane supply lines, compressed air distribution, fire suppression systems, and general mechanical piping. The 3/4-inch size is one of the most frequently specified pipe sizes in residential gas and water service roughing work.

Key Features

• 3/4-inch pipe size for standard threaded iron pipe connections
• Black iron finish suitable for gas line and mechanical piping applications
• Merchant coupling style provides a full-engagement, straight threaded joint
• Packaged in quantities of 80 units per package for job-site or shop stocking

Compatibility

Designed as an OEM-style replacement and standard-stock fitting compatible with 3/4-inch NPT threaded black iron pipe systems.

Installation Notes

Installation should be performed by a licensed plumber or pipefitter in accordance with applicable local mechanical and plumbing codes, including the IFGC for gas applications. Shut off all gas or water supply and verify the line is fully depressurized before cutting into or threading pipe. Apply an approved pipe thread sealant or PTFE tape rated for the service medium to all male threads before assembly. Tighten to snug-plus-hand-tight using proper pipe wrenches; do not over-torque threaded iron fittings.