The B&K 521-220HC is a precision-engineered black iron merchant coupling designed to provide a secure and durable connection between two pipes of matching diameter. With its compact 1/8-inch Female Iron Pipe (FIP) connections on both ends, this coupling is ideal for tight installations and small-diameter piping systems in residential, commercial, and industrial applications.

Constructed from high-quality malleable iron and finished with a black coating, the coupling offers excellent corrosion resistance and long-term durability. Its threaded ends conform to ANSI/ASME B1.20.1 standards, ensuring a tight, leak-resistant seal when paired with compatible black iron fittings. The relative softness of the malleable iron enhances sealing performance, making it a reliable choice for high-pressure systems.

Rated for up to 500 PSI at 150°F, the 521-220HC meets ASTM and ASME standards and is suitable for transporting a wide range of non-potable fluids. Whether used in fluid transport systems or custom DIY projects, this merchant coupling delivers consistent performance and rugged dependability.

Key Features

• Size: 1/8 inch inlet and outlet diameter
• Connection Type: Female Iron Pipe (FIP) on both ends
• Material: Malleable iron
• Finish: Black coating for corrosion resistance
• Product Type: Merchant Coupling
• Threading: ANSI/ASME B1.20.1 compliant
• Pressure Ratings:
  • Working Pressure: 300 PSI
  • Maximum Pressure: 500 PSI at 150°F
• Temperature Range:
  • Minimum: -20°F
  • Working: 77°F
  • Maximum: 224°F
• Dimensions:
  • Length: 0.75 in
  • Height: 0.56 in
  • Width: 0.56 in
  • Weight: 0.028 lbs
• Class: 150-lb malleable fittings
• Compliance: Meets ASTM and ASME standards
• Warranty: 1-year limited warranty
• Brand: Southland
• Unit of Measure: Each

Applications

• Securely connecting two pipes of matching diameter
• Transport of:
  • Lubricants
  • Oils
  • Grease
  • Liquefied petroleum (LP) gases
  • Natural gases (e.g., nitrogen, oxygen)
  • Steam
  • Diesel
• Industrial and commercial fluid systems
• Custom DIY plumbing and mechanical projects