B K/mueller Inds(import) 521-405HN Black Pipe Cap 1 Inch

Product Description

The B K/MUELLER INDS(IMPORT) 521-405HN is a 1-inch black pipe cap designed to terminate the end of a threaded black iron pipe run. It threads onto a male-threaded pipe end to seal the line, prevent contamination, and cap off unused outlets or temporary service ends. At 3.06 pounds per package of 10 units, each individual cap is a solid, heavy-duty fitting suited for gas, air, and other compatible piping applications. Plumbers, pipefitters, and gas service technicians install these in residential and light commercial systems where a clean, secure pipe termination is required.

This cap is used wherever a male-threaded black iron pipe end needs to be closed off. Common applications include capping unused gas outlet stubs, sealing temporary or future branch connections, and closing off test ports on gas distribution piping. The black iron material makes it appropriate for natural gas and propane piping systems as well as compressed air and steam lines, consistent with standard black iron pipe fitting use in residential and commercial mechanical rooms.

Key Features

• 1-inch female threaded opening fits standard 1-inch male NPT pipe ends
• Black iron construction suitable for gas, air, and compatible piping systems
• Sold in a package quantity of 10 units
• Provides a clean, secure termination for unused or capped pipe runs
• Threaded connection for tool-assisted tightening without welding or soldering

Compatibility

Designed as an OEM-style replacement and standard-fit cap for 1-inch male NPT threaded black iron pipe fittings in residential and commercial gas, air, and compatible mechanical piping systems.

Installation Notes

Installation is performed by licensed plumbers or gas fitters in accordance with the International Fuel Gas Code (IFGC) or applicable local codes. Shut off and depressurize the line before installation. Apply an appropriate thread sealant or pipe tape rated for the service medium before threading the cap onto the pipe end. Do not overtighten with power tools, as this can crack or distort the fitting threads.