Merit Brass K419-48 Pipe Locknut 3 in 304 Ss Threaded

Product Description

The MERIT BRASS K419-48 is a 3-inch pipe locknut manufactured from 304 stainless steel for use in threaded piping systems. Locknuts are used to secure fittings, bushings, and other threaded components against a panel, bulkhead, or mating surface, preventing loosening under vibration or flow pressure. This locknut features a Female National Pipe Straight Locknut (FNPSL) end connection, a 150 psi pressure rating, and meets ISO standards. At 4-9/64 inches in length and weighing 1.08 pounds, it is a solid, corrosion-resistant component suited for plumbing, industrial piping, and mechanical system applications installed by licensed plumbers and pipefitters.

This locknut is appropriate for residential and commercial piping installations where a corrosion-resistant, threaded locknut is required at a panel or equipment penetration. The 304 stainless steel construction makes it well suited for wet environments, mild chemical exposure, and applications where galvanic corrosion from ferrous hardware is a concern. The FNPSL thread form provides a straight, non-tapered engagement, which is commonly used in applications requiring a flush or panel-mount seal against a gasket or fitting face.

Key Features

• 304 stainless steel construction for corrosion resistance in wet and industrial environments
• 3-inch fitting size with FNPSL (Female National Pipe Straight Locknut) thread form
• 150 psi pressure rating suitable for standard piping system pressures
• Meets ISO standards for dimensional and performance compliance
• Threaded connection type for straightforward installation with standard pipe tools
• Length of 4-9/64 inches provides adequate engagement depth for secure locknut seating

Compatibility

Designed as an OEM-style replacement or new-installation component for 3-inch threaded piping systems requiring a straight-thread locknut in stainless steel construction.

Installation Notes

Installation of pipe locknuts should be performed by a licensed plumber or pipefitter following applicable IPC and local plumbing code requirements. Depressurize and drain the affected piping section before disassembling any fittings or locknuts. Use appropriate pipe wrenches or strap wrenches sized for 3-inch fittings to avoid damaging the stainless steel surface. Do not over-tighten against plastic panels or soft gasket materials without verifying the rated compression load.