Sigma 811085406 Malleable Iron Reducing Coupling 1/2x3/8 Fnpt

Product Description

The SIGMA 811085406 is a FIG 3121R malleable iron reducing coupling rated for 150 lb service. It connects a 1/2-inch nominal pipe to a 3/8-inch nominal pipe using female National Pipe Taper (FNPT) threads on both ends. The galvanized finish provides corrosion resistance for use in standard gas, air, and water piping systems. Plumbers and pipefitters install this fitting in low-pressure distribution runs where a reduction in pipe diameter is required. It is manufactured from malleable iron, which offers the toughness needed to withstand field installation torque and vibration over the service life of the system.

This reducing coupling is suited for residential and light commercial piping applications including water supply, compressed air distribution, and gas supply lines where a 1/2-inch to 3/8-inch diameter transition is needed. The FNPT threaded ends make it compatible with standard NPT-threaded pipe and fittings. The galvanized coating makes it appropriate for exposed or semi-exposed indoor installations where moisture is a factor.

Key Features

• 1/2 x 3/8 inch nominal reducing connection for same-run diameter transitions
• FNPT threads on both ends for standard NPT pipe compatibility
• 150 lb pressure rating suitable for low-pressure piping service
• Malleable iron construction resists cracking and handles installation torque
• Galvanized finish provides corrosion resistance in moisture-prone environments

Compatibility

Designed as an OEM-style replacement or new-installation fitting for standard 150 lb malleable iron threaded piping systems using 1/2-inch to 3/8-inch NPT connections.

Installation Notes

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

Technical Specifications

• Figure Number: FIG 3121R
• Nominal Size: 1/2 x 3/8 inches
• End Style: FNPT (Female National Pipe Taper)
• Pressure Rating: 150 lb
• Material: Malleable Iron
• Finish: Galvanized

Standard Information

• Brand: SIGMA
• Manufacturer Part Number: 811085406