3 inch x 3-1/2 inch Steel Nipple

3" x 3-1/2" Black Steel Nipple – Threaded Pipe Segment for Heavy-Duty Connections

The 3" x 3-1/2" black steel nipple is a Schedule 40 welded steel component used for extending pipe runs or joining two female-threaded pipe fittings. Precision-machined NPT threads on both ends provide a secure and leak-resistant connection in pressurized mechanical systems, commonly used for gas, air, and hydronic lines.

This fitting is fabricated from ASTM A53 Grade A or equivalent black steel pipe, offering compatibility with standard carbon steel piping systems in both residential and commercial environments. The 3-1/2" length is particularly suited for short offsets, equipment spacing, or inline fittings requiring rigid connectivity.

Product Features

• ✅ Nominal Pipe Size: 3 inch
• ✅ Length: 3-1/2 inches overall
• ✅ Connection Type: NPT threaded ends, conforming to ANSI B1.20.1
• ✅ Material: Welded black steel pipe, typically meeting ASTM A53 or A106 standards
• ✅ Wall Thickness: Schedule 40, suitable for general-purpose pressure systems

Installation Guidance

For best performance, threads should be cleaned and treated with an appropriate pipe joint compound or PTFE tape. Connections should be torqued according to standard pipe-fitting procedures to ensure a pressure-tight seal without damaging the thread geometry. For gas and steam systems, ensure fittings comply with local code requirements and are properly supported to avoid strain.

Common Applications

The 3" x 3-1/2" black steel nipple is routinely used in gas distribution, hydronic heating loops, compressed air piping, and mechanical equipment hookups. It is particularly useful for boiler connections, valve assemblies, and transitions between fittings in confined runs.

Code Compliance

Black steel nipples of this type are widely approved for use in fuel gas and mechanical systems when installed in accordance with local building codes and standards such as the Uniform Plumbing Code (UPC) or International Fuel Gas Code (IFGC).

This 3" x 3-1/2" black steel nipple delivers performance consistency and dimensional reliability, making it a standard component for contractors working on threaded pipe systems in both new construction and retrofit applications.