2-1/2 inch Square Head Black Cast Iron Plug

2-1/2" Black Cast Iron Square Head Plug – Durable Seal for High-Demand Piping Systems

The 2-1/2" Black Cast Iron Square Head Plug is designed for sealing threaded pipe ends in high-pressure systems, offering rugged performance and long-term reliability. Engineered to meet the demands of commercial and industrial-grade applications, this plug helps maintain the integrity of piping networks by providing a dependable closure point where flow is not required.

Key Performance Features

• ✅ Cast Iron Body – Manufactured from ASTM A-126 Class B cast iron for high tensile strength and durability under pressure.
• ✅ Threaded FNPT Connection – Precision tapered threads ensure a secure fit and leak-resistant seal in iron pipe systems.
• ✅ Corrosion-Resistant Finish – Black oxide coating adds an extra layer of protection in non-potable water, steam, and gas applications.
• ✅ Heavy-Duty Design – Engineered for service in waste, vent, and pressure piping applications, both above and below grade.

Technical Specifications

• Material: Black Cast Iron (ASTM A-126, Class B)
• Nominal Size: 2-1/2 inch
• Connection Type: MNPT (Male National Pipe Thread), Square Head
• Working Pressure: Up to 175 PSI (depending on system)
• Temperature Range: -20°F to 300°F (non-shock)

Installation Guidelines

Install using a pipe wrench on the square head with compatible thread sealant or PTFE tape. Ensure threads are clean and dry before application. For critical systems, hydrostatic testing is recommended after installation to verify sealing integrity.

Typical Applications

This plug is frequently used in:

• • Mechanical room piping networks
• • Steam and condensate systems
• • Drainage and vent piping where expansion or inspection access may be required
• • Gas line terminations (in accordance with local codes)

Industry Insight

Square head plugs are preferred in utility and industrial installations due to their easy torque application and low risk of cam-out under load. Cast iron variants remain a cost-effective solution for sealing ferrous piping systems in utility-grade infrastructure.