4 inch Black Iron 90 Degree Elbow Female x Female

4 inch Black Malleable Iron 90° Elbow – Threaded Fitting for Gas and Mechanical Systems

The 4 inch Black Malleable Iron 90-Degree Elbow is a Class 150 threaded pipe fitting used to change the direction of flow in gas, steam, oil, or air piping systems. Manufactured to meet ASTM A197 and ANSI/ASME B16.3 standards, this elbow features two female National Pipe Taper (NPT) threads designed for tight, leak-resistant joints in non-potable systems.

This fitting is cast from black malleable iron and subjected to an annealing process for added ductility. The black finish provides moderate corrosion resistance in low-moisture environments. It is suitable for both residential and commercial mechanical applications, including gas distribution, HVAC infrastructure, and fire protection loops (non-potable).

Technical Specifications

• ✅ Material: Black malleable iron (ASTM A197)
• ✅ Nominal Size: 4 inches
• ✅ Connection Type: Female NPT x Female NPT
• ✅ Conformance: ANSI/ASME B16.3 (fittings), ANSI B1.20.1 (threads)
• ✅ Pressure Rating: 150 PSI maximum for steam or air; 300 PSI maximum for oil or water (non-shock)
• ✅ Bend Angle: 90 degrees

Installation Guidance

Install using pipe wrenches and an approved thread sealant such as PTFE tape or pipe dope rated for the service medium. Ensure proper thread engagement to avoid galling or over-torquing. Threads must be clean and free of debris prior to assembly. Fitting is not intended for welding or use in pressurized potable water systems unless otherwise approved.

Approved Uses

This elbow fitting is designed for directional changes in low- to medium-pressure systems including:

• ✅ Natural gas and propane supply lines
• ✅ Oil burner systems and return loops
• ✅ HVAC piping networks
• ✅ Compressed air piping
• ✅ Industrial steam (non-shock)

Design Considerations

• ✅ Cast Iron Strength: Malleable construction offers resistance to mechanical stress and vibration
• ✅ Standardized Thread Dimensions: Thread form and taper align with ANSI B1.20.1 for universal compatibility
• ✅ High Temperature Tolerance: Suitable for use in high-heat environments, such as gas appliance branches or boiler systems
• ✅ Compact Radius: Useful for installations with limited space or clearance restrictions

Regulatory and Code Notes

Meets applicable mechanical code requirements for gas and non-potable fluid conveyance. Always verify installation practices and material suitability per local code enforcement and authority having jurisdiction (AHJ).

The 4 inch Black Malleable Iron 90° Elbow delivers a reliable solution for directional changes in threaded mechanical systems. Its code-compliant construction and resistance to pressure and temperature fluctuations make it a dependable component in commercial, industrial, and utility-grade installations.