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

2-1/2" x 2" Black Malleable Iron Reducing Coupling – Threaded Fitting for Gas, Steam, and Water Lines

The 2-1/2" x 2" Black Iron Reducing Coupling is a threaded pipe fitting designed to connect two different pipe sizes in a straight-line configuration. Manufactured from malleable iron with a black oxide finish, this coupling is intended for use in non-potable water, natural gas, compressed air, and low-pressure steam systems. The internal threads on both ends are NPT (National Pipe Taper), allowing for a tight mechanical seal without welding or flaring.

This reducing coupling conforms to dimensional standards set by ASME B16.3 and is typically fabricated in accordance with ASTM A197 for material and ASTM A153 for finish. It is suitable for both horizontal and vertical pipe runs where a transition between 2-1/2" and 2" nominal pipe sizes is required.

Product Features

• ✅ Material: Black malleable iron, cast to ASTM A197 specification
• ✅ Finish: Black oxide coating for limited corrosion resistance in dry-system applications
• ✅ Connection Type: Female NPT x Female NPT (ASME B1.20.1 thread standard)
• ✅ Nominal Sizes: 2-1/2" (run) x 2" (branch)
• ✅ Application: Gas piping, HVAC, air lines, non-potable water, low-pressure steam

Installation Guidelines

To ensure leak-resistant connections, apply PTFE tape or a compatible thread sealant to all male-threaded components before assembly. Align pipe ends carefully and tighten using appropriate tools, applying torque within recommended values to avoid overstressing the fitting. Black iron fittings are not suitable for potable water systems or corrosive fluid transport unless internally protected or lined.

Common Applications

This coupling is typically used in mechanical, industrial, and commercial piping systems requiring a transition between two nominal pipe sizes. It is particularly useful in gas manifold assemblies, hydronic loop piping, and steam condensate return lines. The reduced outlet supports flow adjustment in system branches without introducing sharp directional changes.

Standards and Compliance

This fitting meets the dimensional requirements of ASME B16.3 and is UL and FM listed where applicable. It is compatible with Schedule 40 and Schedule 80 steel pipe in accordance with ASME B36.10.

Technical Summary

• Fitting Type: Reducing Coupling
• Connection: NPT Female x NPT Female
• Material: ASTM A197 Black Malleable Iron
• Finish: Black oxide (ASTM A153)
• Nominal Sizes: 2-1/2" x 2"
• Thread Standard: ASME B1.20.1
• Conformance: ASME B16.3, UL/FM (select configurations)