1 inch Black Iron Cap

1" Black Malleable Iron Cap – Threaded Fitting for Line Termination

This 1" black malleable iron cap is engineered to close the end of a threaded pipe in gas, oil, or water systems. Its full-form NPT threading ensures a tight seal, helping to prevent leakage under pressure. Commonly used to terminate lines during system shutdowns, testing, or future expansion, this cap provides a reliable and durable closure point.

Malleable iron offers superior strength under high mechanical stress, and its black oxide finish provides basic corrosion resistance in indoor or non-potable environments. This cap is suitable for steam, air, gas, and fluid piping where galvanized protection is not required.

Product Specifications

• Material: Malleable cast iron, black finish
• Size: 1 inch nominal pipe size
• Connection: Female National Pipe Taper (NPT) threads
• Conforms To: ASTM A197 (casting), ASME B16.3 (dimensions), and ANSI B1.20.1 (threading)

Key Advantages

• High Pressure Resistance: Suitable for use in systems operating up to 150 PSI for steam and 300 PSI for air, water, or oil (depending on application)
• Thread Integrity: Machined for tight tolerance NPT threading to reduce the risk of leakage
• Mechanical Strength: Withstands pipe strain and expansion/contraction without cracking
• Versatility: Applicable in HVAC, fire protection, compressed air, and fuel gas systems

Installation Notes

For best performance, apply a compatible thread sealant or PTFE tape to the male threads prior to installation. Ensure proper alignment and torque without over-tightening to prevent stress fractures in the fitting. This product is intended for use with Schedule 40 or Schedule 80 steel pipe systems and should not be used with potable water unless otherwise specified.

Typical Applications

Commonly used in industrial and commercial mechanical systems, this malleable iron cap is ideal for:

• Sealing off unused branches in gas and steam piping
• Temporary or permanent closures for compressed air systems
• Hydronic heating loop terminations

Note:

This fitting is not suitable for use in corrosive or outdoor environments without additional coating or protection. For potable water systems, refer to galvanized or lead-free alternatives.

Engineered to meet rigorous installation demands, this 1" black malleable iron cap provides a secure and code-compliant termination for pipe systems where strength and pressure containment are critical.