Capitol Manufacturing 12203313 Square Head Plug 1-1/4

Product Description

The CAPITOL MANUFACTURING 12203313 is a 1-1/4 inch square head plug used to cap and seal threaded pipe openings in plumbing, HVAC, and piping systems. Square head plugs are installed into female-threaded fittings or ports to block flow, pressure-test lines, or permanently close unused outlets. This plug is sold as a single unit and is a standard component in trade plumbing and mechanical installations where a secure, wrench-driven closure is required.

This square head plug is suited for residential and commercial piping applications where threaded closures are needed on pipe ends or branch outlets. The square head profile provides a reliable grip point for standard wrenches, making it a practical choice for technicians working in tight or overhead spaces where a traditional hex plug may be harder to torque. Plumbers and pipefitters typically use plugs of this type during pressure testing, system modifications, or when capping off inactive lines.

Key Features

• 1-1/4 inch size fits standard female-threaded pipe fittings of that diameter
• Square head design allows positive wrench engagement during installation and removal
• Sold individually as a single unit
• Suitable for use as a permanent or temporary threaded closure in piping systems

Compatibility

Designed as an OEM-style replacement or standard drop-in fit for 1-1/4 inch female-threaded pipe connections in residential and commercial plumbing and mechanical systems.

Installation Notes

Installation is performed by licensed plumbers or pipefitters following applicable IPC and local plumbing code requirements. Shut off system pressure and drain the line before removing or installing any threaded plug. Apply appropriate thread sealant or PTFE tape to the threads before installation. Do not overtighten - use a properly sized wrench on the square head to achieve a leak-free seal without damaging the fitting.