3/4 inch x 4 inch Black Steel Nipple

3/4" x 4" Black Steel Nipple – Schedule 40, Threaded Carbon Steel Fitting for Mechanical Systems

The 3/4" x 4" Black Steel Nipple is a Schedule 40 carbon steel pipe section machined with male NPT threads on both ends. Designed for joining pipe or fittings in mechanical piping systems, this fitting meets ASTM and ASME standards for pressure-rated gas, steam, air, and water distribution networks.

Fabricated from ASTM A53 Grade B or equivalent carbon steel, this nipple is commonly used in industrial, commercial, and utility piping systems where moderate corrosion resistance and structural strength are required. Its black oxide coating provides surface protection in dry or concealed locations.

Key Specifications

• Nominal Size: 3/4 inch
• Length: 4 inches
• Material: Welded or seamless black steel (ASTM A53, A106)
• Wall Thickness: Schedule 40
• Connection Type: NPT Threaded x NPT Threaded (ASME B1.20.1)
• Finish: Black oxide coating

Performance Features

• ✅ Threaded Ends: Precision-cut NPT threads allow leak-resistant joints when installed with proper sealing compounds.
• ✅ Pressure-Rated: Suitable for use in systems with working pressures up to 150 PSI (depending on system design and media).
• ✅ Corrosion Resistance: Black finish provides protection during installation and in dry, non-potable environments.
• ✅ Mechanical Strength: Schedule 40 wall thickness ensures durability in structurally loaded or vibration-prone piping assemblies.

Application Use

This 3/4" x 4" nipple is used in mechanical and utility systems including:

• Natural gas and propane distribution
• Low-pressure steam and condensate return lines
• Compressed air delivery systems
• Hydronic heating and cooling loops

Installation Guidelines

Use PTFE tape or pipe dope on threaded connections. Tighten with pipe wrenches according to manufacturer torque specifications. All installations should follow applicable local mechanical and plumbing codes. Pipe must be supported appropriately to avoid excessive strain at joints.

Compliance Notes

This black steel nipple is not rated for potable water applications unless it carries the required lead-free certifications. Verify application suitability before use in water systems. It complies with ANSI B1.20.1 thread specs and general ASME B31.1/B31.3 mechanical piping guidelines.

Conclusion

The 3/4" x 4" Black Steel Nipple offers a reliable, pressure-rated connection for threaded pipe assemblies. With Schedule 40 durability, black oxide protection, and code-compliant threading, it is well suited for contractors executing safe and durable installations in gas, air, and process piping systems.