B K/mueller Inds(import) 521-404HN Black Pipe Cap 3/4 in

Product Description

The B K/MUELLER INDS(IMPORT) 521-404HN is a 3/4-inch black pipe cap designed to terminate or seal threaded black iron pipe ends. Pipe caps thread onto male NPT pipe ends, stopping flow and protecting threads from damage, debris, or corrosion during storage, transport, or permanent installation. This part ships in a package quantity of 25 units, making it suited for contractors and service professionals who work with black iron piping systems regularly. Plumbers, pipefitters, and gas service technicians commonly use black pipe caps on fuel gas distribution systems, fire suppression rough-in work, and general black iron piping applications.

Black pipe caps in the 3/4-inch size are used across residential and light commercial installations. Common applications include capping unused branch outlets on gas manifolds, sealing off rough-in piping during pressure testing, and providing permanent end closures on black iron supply lines. The 25-piece package quantity is appropriate for stocking a service van or completing multi-outlet rough-in jobs without repeated orders.

Key Features

• 3/4-inch size fits standard 3/4-inch male NPT threaded black iron pipe
• Black iron construction is compatible with natural gas and propane piping systems
• Threaded cap design installs without special tools — standard pipe wrench or strap wrench applies
• Packaged in quantities of 25 units per package for trade-volume purchasing
• Protects threads and seals pipe ends during pressure testing or permanent closure

Compatibility

Designed as an OEM-style replacement and standard-stock fitting for 3/4-inch male NPT threaded black iron pipe systems.

Installation Notes

Installation is performed by licensed plumbers or gas fitters in jurisdictions where black iron pipe is used for fuel gas distribution. Shut off the gas supply and verify zero pressure at the line before installing or removing any pipe fittings. Apply an approved pipe thread sealant or PTFE tape rated for gas service to the male threads before threading the cap on. Tighten with a pipe wrench to a snug, leak-free fit and perform a pressure test per applicable code — IFGC or local authority having jurisdiction requirements apply.