2-1/2 inch Black Iron Coupling Female x Female

2-1/2" Black Malleable Iron Coupling – Threaded F x F for Schedule 40 Pipe

The 2-1/2" Black Iron Coupling is a straight-line, internally threaded fitting used to connect two male-threaded pipes in low- to moderate-pressure piping systems. Constructed from malleable iron and finished with a black oxide coating, this coupling conforms to ASME B16.3 dimensional standards and is suitable for use in steam, gas, oil, and closed water loop applications where galvanized protection is not required.

Threaded ends are machined to ANSI B1.20.1 National Pipe Thread (NPT) specifications, ensuring a reliable connection between pipes of matching size and schedule. The coupling is commonly used in rigid piping systems requiring full-thread engagement and repeatable dimensional consistency for assembly in mechanical rooms, utility risers, or process equipment.

Performance Characteristics

• ✅ Material: Black malleable cast iron per ASTM A197 / A47
• ✅ Nominal Size: 2-1/2 inches
• ✅ Connection Type: Female NPT x Female NPT
• ✅ Temperature & Pressure: Rated for up to 150 psi at 350°F in steam and hot water systems (non-shock)
• ✅ Standard Compliance: ASME B16.3, UL and FM listed for fire protection systems (when applicable)

Installation Notes

All threaded joints should be sealed with PTFE tape or pipe joint compound per manufacturer instructions. Proper thread engagement and torque are essential to avoid leakage or joint failure. Couplings should not be over-tightened, as excessive force can compromise thread integrity. Threaded iron fittings must be supported in accordance with applicable plumbing or mechanical code.

Typical Applications

Used in black steel piping systems for natural gas distribution, compressed air lines, low-pressure steam systems, and closed-loop hydronic heating. This fitting is suitable for commercial, industrial, and mechanical infrastructure where corrosion protection from galvanization is not necessary.

Material Considerations

Black malleable iron offers moderate corrosion resistance for indoor environments. It should not be used in potable water applications unless lined or specified by code. In systems with high humidity or exposure to corrosive agents, alternative materials or protective coatings may be required.

The 2-1/2" Black Iron Coupling provides a durable, NPT-threaded connection point for assembling steel piping systems in accordance with recognized mechanical standards. Suitable for code-compliant gas and fluid systems under standard operating pressures.