4 inch x Close Black Steel Nipple

4" x Close Black Steel Nipple – For Secure High-Pressure Threaded Connections

The 4" x Close Black Steel Nipple is a precision-fabricated fitting designed for use in piping systems that require a short, direct threaded connection. Manufactured from schedule 40 black steel, this nipple features male National Pipe Thread (NPT) ends and is typically used in gas, oil, steam, and hydronic heating systems.

Its “close” length configuration—threaded nearly to the center—minimizes spacing between connected components, making it ideal for tight assemblies. The fitting is intended for applications where durability, strength, and corrosion resistance in non-potable systems are critical to long-term performance.

Technical Specifications

• Material: Welded black steel (ASTM A53 or equivalent)
• Nominal Pipe Size: 4 inch
• Length: Close (approx. 1.5–2 inches end-to-end, varies by threading)
• Ends: Male NPT x Male NPT
• Wall Thickness: Schedule 40
• Pressure Rating: Rated for up to 150 psi (steam), 300 psi (water/oil/gas)
• Temperature Range: Suitable for use in systems up to 500°F
• Compliance: Meets ANSI B1.20.1 and ASTM A733 specifications

Performance Benefits

• Compact Profile: Close nipple configuration minimizes piping footprint in tight installations
• High-Strength Fabrication: Ideal for heavy-duty systems requiring robust fittings
• Thread Precision: Tapered NPT threads allow for tight, leak-resistant seals when installed with appropriate thread sealant
• Surface Protection: Black oxide finish provides basic corrosion resistance during storage and installation

Common Applications

• Fuel oil distribution lines
• Low-pressure steam systems
• Natural gas and propane piping networks
• Commercial boiler systems

Installation Notes

Ensure proper alignment during installation to prevent cross-threading. Use Teflon tape or pipe joint compound rated for the service type. Avoid overtightening to prevent damage to threads or mating components. Installation should conform to applicable local and national codes.