Merit Brass K419-16 Pipe Locknut 1 in 304 Ss Fnpsl 150 Psi

Product Description

The MERIT BRASS K419-16 is a 1-inch pipe locknut designed to secure fittings and bushings against panel walls, enclosures, and bulkheads in piping systems. Constructed from 304 stainless steel, it delivers corrosion resistance suitable for wet, chemical-exposure, and outdoor environments. The female NPT straight locknut (FNPSL) thread form provides a reliable threaded engagement for locking a fitting in place. Rated at 150 psi, this locknut is appropriate for low-to-medium pressure fluid and gas piping applications. Plumbers, pipefitters, and mechanical contractors install this hardware as a standard component when passing pipe or fittings through a panel or tank wall.

This locknut is suited for residential and light commercial plumbing, process piping, and mechanical system installations where a panel-mount connection must be secured. It is commonly used when installing fittings through control panels, enclosures, or tank walls in water supply, irrigation, and industrial fluid systems. The 304 stainless steel construction makes it a practical choice in applications where mild corrosive conditions or moisture exposure are present. At 1-13/16 inches in length, it accommodates standard 1-inch threaded pipe fittings.

Key Features

• 304 stainless steel construction for corrosion resistance in wet and mildly corrosive environments
• 1-inch fitting size with FNPSL thread form for secure bulkhead and panel-mount applications
• 150 psi pressure rating suitable for low-to-medium pressure piping systems
• 1-13/16 inch length accommodates standard 1-inch threaded pipe fittings
• Sold individually, making it practical for single-point repairs or retrofit installations

Compatibility

Designed as an OEM-style replacement or new-installation locknut for standard 1-inch threaded pipe fittings in residential and commercial plumbing and mechanical piping systems.

Installation Notes

Installation is typically performed by licensed plumbers or pipefitters. Before installation, shut off the water or fluid supply and depressurize the line completely. Thread the locknut onto the fitting by hand first to confirm proper engagement, then tighten with an appropriate pipe wrench or spanner to avoid cross-threading the stainless steel threads. Follow applicable IPC and local plumbing code requirements for pressure ratings and material compatibility at the point of installation.