Bk Mueller 511-203HN Malleable Iron Pipe Coupling 1/2 in

Product Description

The BK MUELLER 511-203HN is a Class 150 malleable iron pipe coupling designed for threaded pipe connections in liquid, gas, and steam service lines. Rated at 300 psi for liquid and gas applications and 150 psi for steam, this galvanized fitting delivers reliable mechanical integrity in demanding service environments. The 1/2-inch threaded end connection makes it compatible with standard NPT piping systems. Plumbers, pipefitters, and mechanical contractors install this type of coupling when joining two sections of threaded pipe in a straight run, particularly in commercial and industrial piping assemblies.

This coupling is suited for residential and light commercial plumbing, gas distribution piping, and steam systems where a Class 150 malleable iron fitting is required. The galvanized finish provides corrosion resistance in exposed or moisture-prone installations. Typical applications include natural gas supply lines, hydronic heating systems, compressed air distribution, and general-purpose liquid piping. Its threaded end connection allows for tool-based installation without welding or soldering.

Key Features

• 300 psi liquid and gas pressure rating for high-demand service lines
• 150 psi steam pressure rating suitable for low-pressure steam systems
• 1/2-inch threaded (NPT) end connection for standard pipe fitting
• Class 150 malleable iron construction for strength and durability
• Galvanized finish for corrosion resistance in wet or exposed environments
• Straight coupling design joins two pipe sections in a continuous run

Compatibility

Designed as an OEM-style replacement and standard-fit coupling for 1/2-inch NPT threaded malleable iron pipe systems in liquid, gas, and low-pressure steam service.

Installation Notes

Installation should be performed by a licensed plumber or pipefitter in accordance with applicable local mechanical and plumbing codes. Shut off all gas or liquid supply and depressurize the line completely before disassembling or replacing any fitting. Apply an appropriate thread sealant or PTFE tape to the male threads before assembly, and tighten using pipe wrenches to achieve a leak-free joint. Do not over-tighten malleable iron fittings, as the material can crack under excessive torque.