Bk Mueller 511-376HN Malleable Iron Reducing Coupling

Product Description

The BK MUELLER 511-376HN is a malleable iron reducing coupling designed to connect threaded pipe of two different diameters in a single inline fitting. It transitions from a 1-1/2-inch pipe to a 1-1/4-inch pipe using standard threaded end connections. Rated at 300 psi for liquid and gas service and 150 psi for steam, this Class 150 fitting is built for demanding mechanical systems. A galvanized finish provides corrosion resistance in wet or exposed environments. It is installed by licensed plumbers and pipefitters working on gas distribution, water supply, and steam piping systems.

This reducing coupling is suited for residential and light commercial applications where a pipe run must be reduced in size between two threaded sections. Typical installations include natural gas branch lines, water distribution piping, compressed air systems, and low-pressure steam lines. The threaded connection style makes it compatible with standard NPT pipe threads, allowing straightforward installation without welding or specialized tooling.

Key Features

• Reduces from 1-1/2-inch to 1-1/4-inch pipe in a single inline fitting
• Rated 300 psi for liquid and gas service
• Rated 150 psi for steam service
• Class 150 malleable iron construction for durability and machinability
• Galvanized finish for corrosion resistance in wet or exposed environments
• Threaded end connections for tool-only installation without welding

Compatibility

Designed as an OEM-style replacement or new-installation fitting for Class 150 malleable iron threaded piping systems carrying liquid, gas, or low-pressure steam.

Installation Notes

Installation should be performed by a licensed plumber or pipefitter in accordance with applicable codes such as the IPC or IFGC. Shut off and depressurize the line before threading or removing any fitting. Apply an approved pipe thread sealant or PTFE tape to male threads before assembly. Do not overtighten; hand-snug plus wrench turns appropriate to the pipe size is standard practice.