Sigma 810081018 Malleable Iron Pipe Coupling 1-1/2 in Fnpt 150 Lb

Product Description

The SIGMA 810081018 is a FIG 3121 malleable iron pipe coupling designed for threaded pipe assemblies in commercial and residential plumbing, HVAC, and mechanical piping systems. This fitting features a 1-1/2 inch nominal female NPT (FNPT) thread on both ends and is rated for 150 lb service. The black oxide finish provides a baseline level of corrosion resistance suitable for dry or interior applications. Licensed plumbers and pipefitters install this coupling to join two lengths of threaded pipe in straight-run configurations. The malleable iron construction offers reliable strength and thread integrity under the pressure and temperature demands typical of standard pipe systems.

This coupling is suited for use in low-pressure gas, water, and steam distribution lines where threaded malleable iron fittings are specified. It is commonly found in commercial mechanical rooms, residential utility piping, and industrial process lines. The 1-1/2 inch nominal sizing makes it a frequent choice for branch and main distribution runs in plumbing and HVAC hydronic systems. It is installed wherever a standard threaded straight coupling is called for in a 150 lb rated malleable iron fitting assembly.

Key Features

• 1-1/2 inch nominal FNPT end style on both ends for standard threaded pipe connections
• 150 lb pressure rating suitable for typical plumbing and mechanical piping service
• Malleable iron construction provides strength and ductility for threaded fittings
• Black oxide finish for corrosion resistance in interior and dry applications
• FIG 3121 pattern — a widely recognized standard malleable iron coupling configuration

Compatibility

Designed as an OEM-style replacement or new-installation fitting for 1-1/2 inch nominal threaded malleable iron pipe systems rated at 150 lb service class.

Installation Notes

Installation should be performed by a licensed plumber or pipefitter in accordance with applicable IPC or IFGC requirements. Shut off and depressurize the line before removing or installing any threaded fitting. Apply an approved thread sealant compound or PTFE tape to the male threads before engagement. Do not over-torque the fitting, as malleable iron threads can be damaged by excessive force.

Technical Specifications

• Nominal Size: 1-1/2 inches
• End Style: FNPT (Female National Pipe Thread) both ends
• Pressure Rating: 150 lb
• Material: Malleable Iron
• Finish: Black Oxide
• Figure Number: FIG 3121

Standard Information

• Brand: SIGMA
• Manufacturer Part Number: 810081018