Merit Brass K619-06 Pipe Locknut 3/8 in 316 Ss 150 Psi

Product Description

The MERIT BRASS K619-06 is a 3/8 inch pipe locknut manufactured from 316 stainless steel for use in threaded piping systems requiring corrosion resistance and reliable mechanical retention. The locknut features a Female National Pipe Straight Locknut (FNPSL) end connection and is rated to 150 psi, making it suitable for moderate-pressure fluid and gas service lines. At approximately 1-1/64 inches in length and weighing just 0.05 pounds, this is a compact, high-integrity fitting appropriate for plumbing, instrumentation, and process piping applications. Installation is performed by licensed plumbers or pipefitters working with stainless threaded systems.

This locknut is used to secure fittings, valves, and instrumentation ports in threaded pipe assemblies where stainless steel is required for corrosion resistance or sanitary compliance. Typical applications include chemical processing lines, marine plumbing, food-grade piping, and potable water systems where carbon steel fittings are not acceptable. The FNPSL connection type is designed for straight-thread locknut engagement. This fitting ships individually and is sold in a minimum quantity of one unit.

Key Features

• 316 stainless steel construction for superior corrosion resistance in wet and chemical environments
• FNPSL (Female National Pipe Straight Locknut) thread form for secure panel or bulkhead mounting
• 150 psi pressure rating suitable for moderate-pressure service
• Conforms to ISO standards for dimensional and performance consistency
• Compact form factor at 1-1/64 inches in length and 0.05 pounds

Compatibility

Designed as an OEM-style replacement or new-install component for 3/8 inch threaded pipe systems requiring an FNPSL locknut in 316 stainless steel.

Installation Notes

Installation should be performed by a licensed plumber or pipefitter familiar with threaded stainless steel fittings. Shut off and depressurize the system before removing or installing any fitting. Use appropriate thread sealant or tape as required by local plumbing codes and ISO standards. Avoid over-tightening, which can distort the locknut or damage the mating thread.