Merit Brass 3611HD-20 Half Coupling 1-1/4 in 316 Ss Fnpt 3000 Psi

Product Description

The MERIT BRASS 3611HD-20 is a 1-1/4 inch pipe half coupling machined from 316/316L dual-certified stainless steel. A half coupling provides a single female-threaded socket used to branch off a run of pipe or cap a pipe end, accepting a male-threaded pipe on one side only. Rated to 3,000 psi, this fitting is built for high-pressure fluid and gas distribution systems where corrosion resistance is critical. The female national pipe taper (FNPT) thread creates a pressure-tight mechanical seal when assembled with a compatible male-threaded pipe. Licensed plumbers, pipefitters, and industrial maintenance technicians are the typical installers.

This half coupling is suited for use in plumbing, process piping, chemical handling, and marine or coastal installations where exposure to corrosive media demands stainless steel over carbon steel or brass. The 316/316L material grade provides enhanced resistance to chlorides, making it a practical choice for saltwater systems, chemical process lines, and sanitary or food-grade piping where pitting and crevice corrosion are concerns. It fits standard 1-1/4 inch NPT pipe in both residential and commercial applications.

Key Features

• 316/316L dual-certified stainless steel construction for superior corrosion resistance
• 3,000 psi pressure rating suitable for high-pressure piping systems
• FNPT end connection for standard tapered pipe thread assembly
• 1-1/4 inch fitting size covers a common pipe diameter in commercial and industrial systems
• Half coupling design allows single-end branch connections without a full coupling

Compatibility

Designed as an OEM-style replacement or new-installation fitting for 1-1/4 inch NPT threaded pipe systems in plumbing and industrial piping applications.

Installation Notes

Installation is typically performed by a licensed plumber or pipefitter in accordance with the International Plumbing Code (IPC) or applicable local codes. Depressurize and isolate the piping system completely before cutting in or replacing any threaded fitting. Apply an appropriate thread sealant or PTFE tape to the male threads before assembly to achieve a leak-free joint. Do not overtighten; hand-snug plus the appropriate number of turns per NPT thread engagement guidelines is sufficient to seat the tapered thread.