Bk Mueller 521-403HN Black Iron End Cap 1/2 in Threaded

Product Description

The BK MUELLER 521-403HN is a threaded malleable iron end cap with a black finish, designed to close off the end of a pipe run in low-pressure gas and liquid piping systems. Sized at 1/2 inch with female iron pipe (FIP) threads, it carries a Class 150 rating and a liquid and gas pressure rating of 300 psi. Malleable iron construction provides the toughness needed in commercial and industrial piping environments as well as residential gas and water distribution. This fitting is installed by licensed plumbers and pipefitters working with threaded black iron pipe systems.

This end cap is suited for use in residential and light commercial applications where threaded black iron pipe is the standard, including natural gas supply lines, steam systems, and general plumbing distribution. The 1/2 inch size fits common branch and supply line terminations. The black finish is appropriate for gas piping installations where code requires identification of non-potable or gas service lines.

Key Features

• Malleable iron construction for durability in gas and liquid service
• Black finish for standard black iron pipe system compatibility
• FIP threaded connection for straightforward hand-and-wrench assembly
• 300 psi pressure rating supports a wide range of piping applications
• Class 150 classification meets standard fitting specifications for low-pressure systems

Compatibility

Designed as an OEM-style replacement and standard-stock fitting for 1/2 inch threaded black malleable iron pipe systems rated at Class 150.

Installation Notes

Installation should be performed by a licensed plumber or pipefitter in accordance with applicable local plumbing and mechanical codes, including IFGC requirements for gas piping. Shut off the gas or water supply and relieve system pressure before threading the fitting onto the pipe. Apply an appropriate pipe thread sealant or PTFE tape rated for the service medium before making up the threaded connection. Do not overtighten with power tools, as malleable iron threads can crack under excessive torque.