Sigma BLCOUP3I-LF 3 Inch Black Imi Coupling

Product Description

The SIGMA BLCOUP3I-LF is a 3-inch black IMI (Iron Malleable Iron) coupling designed for joining pipe sections in plumbing and mechanical piping systems. This lead-free fitting meets requirements for potable water and general distribution applications. Its black iron construction provides durability in both above-ground and in-wall installations. Plumbers and pipefitters select this type of coupling when making straight connections in threaded iron pipe systems, particularly in gas distribution, fire suppression, and non-potable water lines.

This coupling is suited for residential and light commercial plumbing and mechanical piping installations where a 3-inch threaded iron coupling is required. It is commonly installed in gas supply lines, hydronic heating systems, and industrial process piping where black iron fittings are specified. The lead-free designation makes it appropriate for use in systems that may contact potable water, in compliance with applicable plumbing codes.

Key Features

• 3-inch nominal pipe size for use in standard iron pipe systems
• Black iron malleable construction for strength and durability
• Lead-free (LF) designation for potable water compliance
• Threaded connection for straightforward installation with standard pipe wrenches
• Suitable for gas, hydronic, and water distribution applications

Compatibility

Designed as an OEM-style replacement and standard coupling fitting for 3-inch threaded black iron pipe systems.

Installation Notes

Installation should be performed by a licensed plumber or pipefitter in accordance with applicable local codes, including IPC and IFGC requirements. Shut off the water or gas supply and depressurize the line before beginning work. Apply an approved thread sealant or PTFE tape to male threads before assembly and tighten with a pipe wrench to achieve a leak-free joint. Do not over-tighten, as this may crack the fitting or damage threads.

Technical Specifications

• Nominal Pipe Size: 3 inches
• Finish: Black
• Lead-Free: Yes

Standard Information

• Brand: SIGMA
• Manufacturer Part Number: BLCOUP3I-LF