Sigma 811080605 Galvanized Pipe Coupling 1 in Fnpt 150 Lb

Product Description

The SIGMA 811080605 is a Figure 3121 malleable iron pipe coupling designed for threaded pipe assemblies in plumbing, mechanical, and industrial piping systems. The coupling features female NPT (FNPT) end connections on both sides and is rated for 150 lb service, making it suitable for low-pressure gas, water, and steam applications. Constructed from galvanized malleable iron, it resists corrosion in exposed or mildly corrosive environments. The 1-inch nominal size fits standard Schedule 40 threaded pipe. Licensed plumbers and pipefitters install this fitting as part of standard threaded pipe runs, unions, or branch assemblies.

This coupling is intended for use in residential and light commercial piping installations where threaded malleable iron fittings are specified. Typical applications include water supply lines, hydronic heating systems, compressed air distribution, and low-pressure gas piping. The galvanized finish provides added protection in damp or outdoor-adjacent environments. It is commonly used wherever a straight inline connection between two threaded pipe sections is required.

Key Features

• Figure 3121 full coupling with FNPT ends on both sides for standard threaded pipe connections
• 150 lb pressure rating suitable for water, steam, and low-pressure gas service
• Malleable iron construction provides strength and impact resistance in threaded fittings applications
• Galvanized finish for corrosion resistance in exposed or damp environments
• 1-inch nominal size compatible with standard Schedule 40 threaded pipe

Compatibility

Designed as an OEM-style replacement or new-installation fitting for 1-inch nominal threaded pipe systems using 150 lb malleable iron fittings per ANSI/ASME B16.3 standards.

Installation Notes

Installation should be performed by a licensed plumber or pipefitter in accordance with applicable local plumbing codes and the International Plumbing Code (IPC) or International Fuel Gas Code (IFGC) where gas service applies. Shut off the relevant water, gas, or compressed air supply and relieve system pressure before disassembling or installing threaded fittings. Apply an approved thread sealant or PTFE tape to the male threads before making up the joint. Do not over-tighten, as malleable iron fittings can crack under excessive torque applied without measurement.

Technical Specifications

• Figure Number: 3121
• Nominal Size: 1 inch
• End Style: FNPT (Female National Pipe Thread) both ends
• Pressure Rating: 150 lb
• Material: Malleable Iron
• Finish: Galvanized

Standard Information

• Brand: SIGMA
• Manufacturer Part Number: 811080605