Sigma 23MC4012 Pipe Coupling 1-1/4 in Carbon Steel Sch 40

Product Description

The SIGMA 23MC4012 is a carbon steel pipe coupling designed for joining sections of threaded pipe in industrial and commercial plumbing systems. Built to Schedule 40/Standard wall specifications, this coupling features NPSC (National Pipe Straight Coupling) threading on both ends and a black oxide finish that provides a degree of corrosion resistance in dry or low-moisture environments. At 1-1/4 inches nominal pipe size, it suits a wide range of mid-size piping runs. Licensed plumbers and pipefitters install this type of fitting as a standard connection component in pressure and drainage systems.

This coupling is appropriate for residential and commercial gas, water, and mechanical piping applications where Schedule 40 carbon steel fittings are specified. The NPSC end style provides straight-thread engagement, making it suitable for joining pipe ends without taper. It is commonly used in mechanical rooms, industrial process lines, and building service piping where a full-port, in-line connection is required between two pipe segments of equal nominal size.

Key Features

• Carbon steel construction suitable for Schedule 40 and standard-wall piping systems
• 1-1/4 inches nominal pipe size for mid-range piping runs
• NPSC straight-thread end style on both ends for in-line pipe joining
• Black oxide finish for identification and surface protection in low-moisture service
• SCH 40/STD wall rating for standard-pressure piping applications

Compatibility

Designed as an OEM-style replacement or new-installation fitting for 1-1/4 inch nominal Schedule 40 carbon steel threaded pipe systems.

Installation Notes

Installation should be performed by a licensed plumber or pipefitter in accordance with applicable codes such as the IPC or IFGC. Shut off and depressurize the pipe system fully before disassembly or fitting installation. Apply an appropriate thread sealant or PTFE tape to the pipe threads before engagement; do not use sealant on NPSC straight-thread joints without confirming the mating component is designed for that sealing method. Inspect threads for damage before assembly.

Technical Specifications

• Material: Carbon Steel
• Nominal Pipe Size: 1-1/4 inches
• Wall Schedule: SCH 40/STD
• End Style: NPSC (National Pipe Straight Coupling)
• Finish: Black Oxide

Standard Information

• Brand: SIGMA
• Manufacturer Part Number: 23MC4012