Sigma 810087809 Malleable Iron Reducing Coupling 1-1/4x3/4 in

Product Description

The SIGMA 810087809 is a FIG 3121R malleable iron reducing coupling designed for threaded pipe assemblies in low-pressure gas, water, and steam distribution systems. It features female NPT (FNPT) ends on both sides, reducing from a 1-1/4 inch nominal pipe size to a 3/4 inch nominal pipe size. Rated at 150 lb, this fitting is finished in black oxide to provide corrosion resistance in dry or mildly humid environments. Plumbers and pipefitters install this coupling when stepping down pipe diameter within a run, making it a staple in mechanical rooms, utility systems, and industrial piping layouts.

This reducing coupling is suited for residential and light commercial piping applications where a threaded reduction in line size is required. It is commonly installed in water supply lines, low-pressure steam systems, and gas distribution piping. The FNPT thread pattern on both ends allows direct engagement with standard NPT-threaded pipe and fittings, simplifying assembly in tight spaces or existing threaded systems.

Key Features

• Malleable iron construction provides impact resistance and durability under thermal cycling
• 150 lb pressure rating suitable for low-pressure water, steam, and gas service
• FNPT ends on both sides accept standard NPT-threaded pipe for tool-free dry fitting and easy assembly
• Black oxide finish offers baseline corrosion protection in dry and indoor environments
• Reduces from 1-1/4 inch nominal to 3/4 inch nominal in a single inline fitting

Compatibility

Designed as an OEM-style replacement or new-installation fitting for standard 150 lb malleable iron threaded pipe systems using NPT connections.

Installation Notes

Licensed plumbers or pipefitters should install this fitting in accordance with applicable local mechanical and plumbing codes, including IFGC requirements where used on gas lines. Shut off and depressurize the system fully before removing any existing fittings or threading new pipe. Apply an approved pipe thread sealant or PTFE tape to all male threads before assembly. Do not over-tighten, as malleable iron threads can crack under excessive torque.