Threaded 1-1/2" NPT female pipe cap for sealing off the end of a male-threaded steel pipe run. Standard malleable-iron Class 150 fitting used to terminate gas, water, air, drain, or structural pipe where the line stops or is shut in for future extension. Domestically manufactured.

• Size: 1-1/2" NPT female thread (FIP)
• Material: Malleable iron with galvanized finish
• Pressure rating: Class 150 (150 psi WSP steam / 300 psi WOG cold non-shock)
• Standard: ANSI/ASME B16.3 malleable iron threaded fittings
• Domestic manufacture
• MPN: 8700132858

Service: Galvanized (hot-dip zinc-coated) steel pipe and fittings are used for cold-water supply, drain/waste/vent (DWV), compressed air, fire-sprinkler service, and exterior structural pipe (handrails, fence rails, conduit). The zinc coating resists corrosion in wet service. Not recommended for natural gas -- older NFPA codes restrict galvanized on gas service because zinc flake can break loose and lodge in valves or burner orifices. For potable water, modern code increasingly favors copper, PEX, or CPVC over galvanized due to scale buildup and lead-solder concerns on older joints, but galvanized remains common for compressed-air and DWV branch caps.

Cap-off Use: Use a pipe cap to permanently or temporarily seal the end of a male-threaded pipe run -- closing off a removed appliance branch, shutting in a future extension stub, or testing a pressurized section by isolating it. Pair with a corresponding pipe plug when you need to seal the female end of a fitting instead of the male end of a pipe.

Installation Tip: Wrap the male pipe threads with PTFE thread tape (3-4 turns clockwise looking at the pipe end, so the tape pulls into the threads as you screw on the cap) or apply a thin film of pipe-thread compound rated for the service. Thread the cap on hand-tight, then turn 1-2 additional turns with a pipe wrench until the cap seats firmly. Do not over-tighten -- cast iron can crack at the bell if forced past full engagement. For gas service use yellow gas-rated PTFE tape and pressure-test the joint with leak-detection solution before returning the line to service.