Merit Brass 618B-12 Hex Countersunk Pipe Plug 3/4 in Mnpt

Product Description

The MERIT BRASS 618B-12 is a hex countersunk pipe plug designed to close off threaded pipe ends and fittings in fluid and gas systems. Manufactured from 316/316L stainless steel, it offers strong resistance to corrosion, making it well suited for installations exposed to moisture, chemicals, or marine environments. The male NPT (MNPT) threaded end seats securely into standard female-threaded ports. Rated to 150 psi, this plug handles typical low-pressure piping applications. At 0.5 inches in length and 0.1 pounds, it is a compact, easy-to-install fitting for plumbers and pipefitters working in commercial and industrial settings.

This plug is used to cap or seal unused pipe outlets on 3/4 inch female-threaded ports in plumbing, process piping, and fluid handling systems. The countersunk hex drive allows installation with a socket or hex key where clearance is limited, making it practical for tight panel, manifold, or equipment body applications. It is appropriate for both new construction and maintenance work across a wide range of piping systems where stainless steel material compatibility is required.

Key Features

• 316/316L stainless steel construction for corrosion resistance in demanding environments
• MNPT threaded end for secure engagement with standard female NPT ports
• Hex countersunk drive allows installation in restricted-clearance locations
• 150 psi pressure rating suitable for standard low-pressure service
• Compact 0.5 inch length for use in tight or flush-mount applications

Compatibility

Designed as an OEM-style replacement or new-installation fitting for 3/4 inch female NPT threaded pipe ports in standard 150 psi rated piping systems.

Installation Notes

Installation is performed by licensed plumbers or qualified pipefitters. Shut off system pressure and drain the line before removing or installing any threaded pipe fitting. Apply thread sealant or PTFE tape appropriate for the service fluid before threading the plug into the port. Tighten using a hex key or socket to achieve a leak-free seal without over-torquing the stainless threads.