3/4 inch x 1/8 inch Black Iron Reducing Coupling Female x Female

3/4 Inch x 1/8 Inch Black Iron Reducing Coupling – Female NPT x Female NPT

The 3/4 inch x 1/8 inch Black Iron Reducing Coupling is a threaded malleable iron fitting designed to connect two different nominal pipe sizes in a low- to medium-pressure system. With female National Pipe Thread (NPT) ends, this fitting is used to reduce a larger diameter pipe to a smaller one while maintaining a sealed connection in mechanical, fuel gas, steam, and air distribution systems.

Product Features

• ✅ Malleable Iron Construction – Manufactured from ASTM A197 black malleable iron for strength, dimensional stability, and thermal resistance.
• ✅ Threaded End Connections – NPT threads comply with ANSI B1.20.1, providing a secure seal when installed with appropriate thread sealants.
• ✅ Reduced Configuration – Facilitates direct transition between two pipe sizes without additional bushings or multiple fittings.
• ✅ Corrosion-Resistant Coating – Black iron finish offers resistance to scaling and light surface oxidation in dry systems.

Technical Specifications

• Material: Black Malleable Iron
• Connection Type: Female NPT x Female NPT
• Nominal Sizes: 3/4 inch x 1/8 inch
• Thread Standard: ANSI B1.20.1 (tapered pipe thread)
• Pressure Rating: Class 150 – suitable for up to 300 PSI (non-shock water/oil) and 150 PSI steam
• Conformance: ASME B16.3 and B16.14

Typical Applications

This reducing coupling is suitable for joining black steel or iron pipe in mechanical systems where changes in diameter are required. Typical use cases include:

• Natural gas or LP piping networks
• Low-pressure steam or condensate systems
• Hydronic heating loops
• Compressed air or vacuum systems (non-potable)

Installation Guidelines

Apply approved pipe thread sealant (e.g., PTFE tape or pipe joint compound) to male threads before installation. Do not overtighten, as this can distort threads or crack fittings. Install using appropriate pipe wrenches and verify alignment to avoid cross-threading.

The 3/4 inch x 1/8 inch Black Iron Reducing Coupling provides a compact, code-compliant method for diameter transition in threaded piping systems. Its mechanical strength and dimensional accuracy make it a reliable solution for pressure-rated applications across commercial, residential, and industrial settings.