Sigma 811088608 Reducing Coupling 1-1/2x3/4 in Fnpt 150lb

Product Description

The SIGMA 811088608 is a malleable iron reducing coupling designed to connect pipe sections of two different nominal sizes within a threaded piping system. Configured as a FIG 3121R style fitting, it transitions from a 1-1/2 inch nominal female connection to a 3/4 inch nominal female connection using standard FNPT threads on both ends. The galvanized finish provides corrosion resistance for use in water distribution, compressed air, and general industrial piping. Rated at 150 lb, this coupling meets standard pressure class requirements for threaded malleable iron fittings. Licensed plumbers and pipefitters are the typical installers.

This reducing coupling is suited for residential and light commercial plumbing, gas distribution, compressed air lines, and industrial piping applications where a threaded step-down transition between 1-1/2 inch and 3/4 inch pipe is required. The FNPT end style accepts standard NPT-threaded pipe on both ends, making it compatible with common pipe materials including black iron, galvanized steel, and other NPT-compatible piping. The galvanized finish is appropriate for wet or corrosion-prone environments.

Key Features

• Reduces from 1-1/2 inch nominal to 3/4 inch nominal in a single fitting
• FNPT threads on both ends for standard NPT pipe connections
• 150 lb pressure class rating for threaded malleable iron service
• Galvanized finish for corrosion resistance in wet or outdoor environments
• Malleable iron construction provides durability and thread integrity
• FIG 3121R pattern for dimensional interchangeability with standard reducing coupling specifications

Compatibility

Designed as an OEM-style replacement and standard-service reducing coupling for 150 lb class threaded malleable iron piping systems using 1-1/2 inch to 3/4 inch NPT connections.

Installation Notes

Installation is performed by licensed plumbers or pipefitters in accordance with applicable plumbing codes such as the IPC or IFGC. Shut off and depressurize the piping system before removing or installing any threaded fitting. Apply an approved thread sealant or PTFE tape to the male NPT threads before assembly. Do not over-tighten; use a pipe wrench to achieve a snug, leak-free joint without stressing the fitting.

Technical Specifications

• Nominal Size: 1-1/2 x 3/4 inches
• End Style: FNPT (Female National Pipe Thread) both ends
• Pressure Rating: 150 lb
• Material: Malleable Iron
• Finish: Galvanized
• Figure Number: FIG 3121R

Standard Information

• Brand: SIGMA
• Manufacturer Part Number: 811088608