Bk Mueller 521-341HC Black Reducing Coupling 3/4x1/4

Product Description

The BK MUELLER 521-341HC is a black malleable iron reducing coupling rated for Class 150 service and designed to connect a 3/4-inch pipe to a 1/4-inch pipe using female iron pipe (FIP) threaded connections on both ends. Rated to 300 psi, this fitting handles both liquid and gas pressure service. The black finish is standard for gas distribution piping and similar industrial applications. It is installed by licensed plumbers, pipefitters, and HVAC technicians working with threaded iron pipe systems in residential, light commercial, and industrial environments.

This reducing coupling is suited for gas supply lines, water distribution, and compressed air applications where a reduction in pipe size is required between a 3/4-inch and 1/4-inch run. The FIP thread standard ensures compatibility with standard NPT-threaded pipe and fittings. It is a common component in gas appliance rough-in work, boiler piping, and mechanical room installations where threaded black iron pipe is specified.

Key Features

• Malleable iron construction for strength and durability in threaded piping systems
• Black finish standard for gas service piping applications
• Class 150 rated with 300 psi liquid and gas pressure rating
• Female iron pipe (FIP) threads on both ends for standard NPT compatibility
• Reduces from 3/4 inch to 1/4 inch in a single compact fitting

Compatibility

Designed as an OEM-style replacement or new-installation fitting for standard threaded black iron pipe systems using NPT-compatible fittings in Class 150 service.

Installation Notes

Installation is performed by licensed plumbers, pipefitters, or qualified HVAC technicians. Shut off the gas or water supply and depressurize the line before threading any fittings. Apply an approved pipe thread sealant or PTFE tape to male threads before assembly; do not apply sealant to female threads. Verify all connections with a leak test before returning the system to service, following applicable local codes and IFGC requirements for gas piping.