4 inch x 3 inch Black Iron Reducing Coupling Female x Female

4" x 3" Black Iron Reducing Coupling – Threaded Female Ends

The 4 inch x 3 inch Black Iron Reducing Coupling is manufactured to ANSI standards for use in threaded piping systems that require a transition between pipe sizes. Constructed from robust black malleable iron, this fitting is intended for general service applications including air, oil, steam, and gas lines in both residential and commercial settings.

Product Features

• ✅ Thread Type: NPT (National Pipe Thread), female x female, conforming to ANSI B1.20.1 for compatibility with standard threaded pipe
• ✅ Material Composition: Black malleable iron per ASTM A197
• ✅ Design: Reducing coupling with concentric alignment for smooth flow transition
• ✅ Operating Range: Suitable for systems operating at up to 150 psi steam, 300 psi air or water (non-shock), when used within temperature limits

Dimensional and Mechanical Specifications

• Nominal Sizes: 4" x 3"
• Connection Type: FPT x FPT (Female Pipe Thread)
• Pressure Rating: Meets or exceeds Class 150 specifications
• Finish: Uncoated black iron for interior use or environments where corrosion protection is not required

Application Scope

• ✔ Natural gas and LP piping systems
• ✔ Steam distribution in low-pressure systems
• ✔ Industrial process piping for air, oil, or inert gas
• ✔ Mechanical installations in HVAC networks and boiler rooms

Installation Notes

Install using pipe wrenches and appropriate thread sealants compatible with the system’s media. For gas lines, follow local code requirements and manufacturer recommendations for thread sealing materials. Do not overtighten; ensure alignment to avoid stress on mating threads.

Code Compliance and Industry Standards

• Material Standard: ASTM A197 (malleable iron)
• Thread Standard: ANSI B1.20.1 (NPT)
• Pressure Ratings: ANSI/ASME B16.3 for cast iron threaded fittings

The 4" x 3" Black Iron Reducing Coupling provides a reliable transition between pipe sizes in pressure-rated threaded systems. It is designed to meet the demands of industrial-grade service conditions, offering long-term performance for piping professionals requiring dependable flow control in size-reduction scenarios.