Merit Brass XNL119-02 Brass Pipe Locknut 1/8 in Fnpt

Product Description

The MERIT BRASS XNL119-02 is a lead-free brass pipe locknut designed to secure fittings and threaded connections in piping systems. It features female NPT (FNPT) threading and a Class 125 pressure rating of 125 psi, making it suitable for low-pressure plumbing, gas distribution, and instrumentation lines. The locknut is machined from brass, offering corrosion resistance in both wet and dry service environments. Plumbers and pipefitters typically install this type of fitting to lock threaded nipples and bushings firmly in place on panels, manifolds, or fixtures. Its compact 1/8 inch size suits tight-space applications common in residential and light commercial installations.

This locknut is used wherever a 1/8 inch FNPT threaded connection requires mechanical securing. Typical applications include panel-mount fittings, gauge ports, manifold assemblies, water supply lines, and low-pressure gas line accessories. The lead-free construction meets requirements for potable water contact, making it appropriate for drinking water systems in addition to HVAC hydronic and refrigeration piping where 1/8 inch ports are common. A licensed plumber or pipefitter installs this fitting in both new construction and retrofit service work.

Key Features

• Lead-free brass construction meets potable water contact requirements
• FNPT threaded connection for standard NPT piping systems
• Class 125 rating at 125 psi working pressure
• 1/8 inch fitting size for compact port and gauge applications
• Corrosion-resistant brass material suitable for wet and dry service

Compatibility

Designed as an OEM-style replacement or new-installation locknut for standard 1/8 inch FNPT threaded piping systems rated at Class 125 or lower.

Installation Notes

Installation should be performed by a licensed plumber or pipefitter in accordance with applicable IPC or local plumbing codes. Shut off and depressurize the supply line completely before removing or installing any threaded fitting. Use appropriate pipe thread sealant or PTFE tape on the male threads before tightening. Do not overtighten brass fittings, as the material is subject to cracking under excessive torque.