B K/mueller Inds(import) 521-802HN 3/8 Inch Black Plug

Product Description

The B K/MUELLER INDS(IMPORT) 521-802HN is a 3/8-inch black pipe plug used to seal open pipe ends and fittings in plumbing, gas, and mechanical piping systems. This plug provides a secure, pressure-rated closure for threaded pipe ports and is a standard component in residential and light commercial installations. Licensed plumbers and pipefitters install this type of fitting during system assembly, maintenance, and pressure testing. Sold in a pack of 10, this plug is well suited for jobs requiring multiple closures or for stocking a service van with commonly needed sizes.

The 521-802HN is appropriate for use in black iron pipe systems commonly found in natural gas lines, propane distribution, steam systems, and general fluid-handling applications where a threaded 3/8-inch male plug is required. The black finish is standard for gas-rated black iron fittings. Contractors and service technicians use this plug to cap unused tees, close test ports, and blank off branch lines during system modifications or expansions.

Key Features

• 3/8-inch thread size for standard pipe fitting compatibility
• Black finish consistent with black iron gas and fluid piping systems
• Sold in a 10-piece pack for multi-point or van-stock applications
• Threaded male plug design for sealing open female-threaded ports
• Lightweight at 0.48 pounds per pack

Compatibility

Designed as a standard threaded plug for use in 3/8-inch female NPT fittings in black iron pipe systems typical of residential and light commercial gas and fluid piping installations.

Installation Notes

Installation of gas-line fittings must be performed by a licensed plumber or gas fitter in accordance with the International Fuel Gas Code (IFGC) and applicable local codes. Shut off the gas or fluid supply and relieve system pressure before threading in the plug. Apply an appropriate pipe thread sealant or PTFE tape rated for the intended media. Pressure-test the fitting after installation to confirm a leak-free seal.