Premium Black Malleable Iron Plain Plug (ASME B16.14 and ASTM A197 Compliant)
Engineered specifically for heavy-duty natural gas, LP (liquid propane), and mechanical piping networks, our Premium Black Malleable Iron Plain Plugs provide a highly dependable, permanent or temporary termination point for open pipe runs. Manufactured from high-strength cupola malleable iron, these threaded solid plugs are built to safely seal off unused ports, equipment headers, or structural distribution lines under constant system pressures and mechanical vibration.
Featuring precision-cut external National Pipe Taper (NPT) threads, these solid plugs ensure an exceptionally tight mechanical wedge fit when threaded into female fittings or appliance blocks. Every fitting is factory pressure-tested to guarantee zero wall porosity, offering ultimate safety behind walls or within mechanical rooms.
Key Features and Benefits
Heavy-Duty Malleable Iron Construction: Cast from premium ASTM A197 cupola malleable iron, delivering excellent tensile strength and structural fatigue resistance. It will not crack or fracture under heavy pipe wrench installation torque.
Solid Leak-Proof Line Termination: Provides a reliable, water-tight and gas-tight seal at the end of a plumbing run or unused manifold port, allowing you to isolate specific zones or safely seal off stub-out lines.
Precision-Tapered External NPT Threads: CNC-machined to strict ASME B1.20.1 standards. The smooth, deep-cut external threads allow thread sealants or tape to distribute uniformly, creating a gas-tight seal that completely eliminates bypass leaks.
Robust Wrench Grip Profile: Designed with a standard square head or heavy hex head profile, providing maximum gripping surface for a pipe wrench or crescent wrench to ensure tight leverage and easy installation or removal.
Naturally Finished Black Coating: Treated with a raw black oxide finish and a light factory oil coat to provide dependable storage protection against atmospheric humidity and oxidation before job-site installation.
Technical Specifications
Fitting Profile: Plain End Plug / Solid Threaded Pipe Plug (Square or Hex Drive)
Material Standard: ASTM A197 / A197M Cupola Malleable Iron Castings
Dimensional Standard: ASME B16.14 (Ferrous Pipe Plugs, Bushings, and Locknuts with Pipe Threads)
Thread Specification: ANSI / ASME B1.20.1 National Pipe Taper External Threads
Pressure and Temperature Ratings: Rated for up to 300 PSI at 150 degrees Fahrenheit, or 150 PSI at 300 degrees Fahrenheit
Fluid Compatibility: Natural gas, liquid petroleum (LP) gas, compressed air, oils, and non-potable closed systems (Note: Not for use in domestic potable water lines due to rust risks).
Ideal Applications
Capping Off Open Gas Lines and Manifold Ports During System Additions and Structural Pressure Testing
Terminating Unused Branch Lines or Abandoned Stub-Outs Behind Finished Building Framing
Sealing End Ports on Commercial Compressed Air Distribution Rails and Storage Tanks
Isolating Specific Gas Plumbing Zones During Multi-Stage Renovation and Mechanical Repair Work
