1-1/2 inch x 3/4 inch Black Iron Reducing Coupling Female x Female

1-1/2" x 3/4" Black Malleable Iron Reducing Coupling – Threaded Fitting for Pipe Size Transition

The 1-1/2" x 3/4" Black Malleable Iron Reducing Coupling is a threaded fitting used to connect two different nominal pipe sizes in gas, air, or low-pressure water systems. Constructed from ASTM A197 malleable iron and finished with a black oxide coating, this reducing coupling provides a reliable, pressure-rated solution for mechanical and industrial piping applications.

Its female National Pipe Taper (NPT) threads on both ends allow for secure connections with standard threaded carbon steel or black iron pipe. The compact, one-piece design is ideal for tight spaces where reduction in line diameter is required without the use of additional bushings or adapters.

Product Features

• ✅ Material: Black Malleable Iron conforming to ASTM A197 for structural durability and machinability.
• ✅ Connection Type: Female NPT x Female NPT – per ANSI/ASME B1.20.1 thread standard.
• ✅ Nominal Size Transition: 1-1/2" to 3/4" – commonly used in branch connections and equipment transitions.
• ✅ Pressure Rating: 150 PSI for steam; 300 PSI for water, oil, or gas (WOG) service in non-corrosive systems.

Technical Specifications

• Standard Compliance: ANSI/ASME B16.3 (dimensions), B1.20.1 (threads)
• Coating: Black oxide finish for interior use or controlled dry environments
• Application Type: Reducing fitting for use in non-potable piping systems

Typical Use Cases

This reducing coupling is widely installed in fuel gas piping networks, boiler room branch lines, process piping systems, and equipment connections where a reduction from a 1-1/2" main line to a 3/4" service line is required. Frequently used in industrial plants, mechanical rooms, and HVAC piping layouts.

Installation Notes

Ensure clean, properly threaded pipe ends and apply an approved thread sealant or PTFE tape for leak-free installation. Avoid over-torqueing, which may compromise threads or lead to misalignment. Verify compatibility with system materials and pressure ratings during design review.

The 1-1/2" x 3/4" Black Malleable Iron Reducing Coupling provides a reliable and code-compliant transition fitting for professional piping assemblies. Its solid construction, tight thread tolerance, and mechanical strength make it an essential component in high-integrity mechanical system builds.