3 inch x 5-1/2 inch Black Steel Nipple

3" x 5-1/2" Black Steel Nipple – Threaded Schedule 40 Pipe for High-Pressure Applications

The 3 inch x 5-1/2 inch Black Steel Nipple is a precision-machined pipe fitting constructed from Schedule 40 seamless steel, suitable for high-pressure steam, water, and gas distribution systems. Manufactured to ANSI/ASME B1.20.1 standards, it features NPT male threads on both ends, delivering dependable joint integrity in mechanical and industrial piping systems.

Used extensively in oil and gas infrastructure, HVAC systems, and commercial plumbing installations, this black steel nipple is fabricated from uncoated carbon steel, providing the strength and temperature tolerance required for demanding environments where corrosion from external moisture is not a primary concern.

Key Performance Attributes

• ✅ Heavy-Duty Construction – Manufactured from ASTM A106 Grade B or equivalent seamless steel for high mechanical strength.
• ✅ Precision Threading – Tapered NPT threads cut to ANSI B1.20.1 specifications for optimal sealing performance with compatible fittings.
• ✅ Uncoated Finish – Ideal for interior gas and air systems where protective galvanization is unnecessary.
• ✅ Short Run Applications – Used for extending or connecting sections of pipe in close-quarters layouts or between rigid components.

Technical Specifications

• Nominal Pipe Size: 3 inch
• Length: 5-1/2 inch (overall including thread length)
• Material: Black steel, Schedule 40
• Thread Type: NPT (National Pipe Thread) Male x Male
• Manufacturing Standard: ASTM A733, ANSI B1.20.1

Installation Guidance

Use thread sealant or PTFE tape to ensure proper sealing on the NPT threads. Hand-tighten first, followed by wrench-tightening per torque specifications. Avoid over-tightening to prevent thread damage. Ensure compatibility with adjacent components and inspect for surface integrity before installation in pressurized systems.

Applications

This black steel nipple is commonly specified in:

• Natural gas and LP gas line installations
• Hydronic heating loops
• High-temperature air, steam, and process systems
• Industrial compressed air lines

Field Insight

Black steel is preferred over galvanized pipe in gas delivery systems due to the absence of zinc coatings, which can flake under heat or pressure and compromise line integrity. It remains a code-approved choice for non-potable and combustive gas conveyance.

The 3" x 5-1/2" Black Steel Nipple delivers the robust performance required in professional-grade installations. Designed to meet rigorous mechanical demands, it is a proven solution for secure, high-strength connections in critical system assemblies.