Sigma 810080606 Fig 3121 Pipe Coupling 1 Inch Fnpt 150 Lb

Product Description

The SIGMA 810080606 is a FIG 3121 full pipe coupling designed for threaded pipe connections in plumbing, mechanical, and fire protection systems. It features female NPT (FNPT) threads on both ends and is rated at 150 lb, making it suitable for standard low-pressure piping applications. Constructed from malleable iron with a black oxide finish, this coupling offers reliable strength and corrosion resistance in typical indoor piping environments. Licensed plumbers and pipefitters use this type of fitting to join two lengths of threaded pipe in a straight run without reducing the bore.

This coupling is used in residential and light commercial piping systems, including gas distribution, steam, water, and air lines where malleable iron threaded fittings are specified. The 1 inch nominal size and standard FNPT thread pattern make it a common choice for service, repair, and new construction work where iron pipe is used. The black oxide finish is standard for non-galvanized iron pipe assemblies.

Key Features

• Full coupling with FNPT threads on both ends for straight pipe-to-pipe connections
• 1 inch nominal pipe size fits standard 1 inch NPT threaded pipe
• 150 lb pressure rating suitable for standard plumbing and mechanical service
• Malleable iron construction provides strength and impact resistance over cast iron
• Black oxide finish for use in non-corrosive indoor piping environments

Compatibility

Designed as an OEM-style replacement or new-installation fitting for 1 inch nominal NPT threaded pipe systems using malleable iron fittings rated at 150 lb.

Installation Notes

Installation is performed by licensed plumbers or pipefitters. Shut off and depressurize the piping system fully before removing or installing any threaded fitting. Apply approved thread sealant or PTFE tape to male threads before assembly and tighten using pipe wrenches to achieve a proper seal without over-stressing the fitting. Follow applicable IPC and IFGC codes for the specific service type.

Technical Specifications

• Nominal Pipe Size: 1 inch
• 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: 810080606