Service Metal
300# Black Malleable Caps
- SKU:
- XBCP
- Availability:
- Usually Ships Same Day
- Weight:
- 0.00 LBS
Description
300# Black Malleable Iron Cap
300# Black Malleable Iron Caps are designed to securely close the end of male-threaded pipe in higher-duty piping systems.
Manufactured from durable malleable iron, these Class 300 caps provide a dependable threaded closure for industrial, commercial, plumbing, mechanical, gas, air, oil, and compatible fluid piping applications where pipe termination, isolation, testing, or future expansion points are required.
Product Highlights
- Threaded pipe cap for closing the end of a pipe run
- Female NPT threaded connection
- Designed for higher-duty Class 300 threaded piping systems
- Suitable for permanent or temporary pipe termination
- Useful for maintenance, testing, isolation, and future expansion
- Durable black malleable iron construction
- Malleable castings conform to ASTM A197
- Malleable fitting dimensions conform to ASME B16.3
- NPT threads conform to ASME B1.20.1
- Class 300 fittings are UL Listed
- Suitable for gas, oil, air, and compatible fluid piping systems
- Manufactured in an ISO-certified facility
- Country of origin: Thailand & China
Technical Specifications
| Product Type | Pipe Cap |
|---|---|
| Material | Malleable Iron |
| Finish | Black |
| Pressure Class | 300# |
| Connection Type | Female NPT |
| Configuration | Threaded End Closure |
| Primary Function | Seal / Terminate Male-Threaded Pipe |
| Casting Standard | ASTM A197 |
| Dimensional Standard | ASME B16.3 |
| Thread Standard | ASME B1.20.1 |
| Listing | Class 300 Fittings are UL Listed |
| Manufacturing | ISO-Certified Facility |
| Country of Origin | Thailand & China |
Construction & Applications
Malleable Iron Construction
Manufactured from malleable iron castings conforming to ASTM A197 for dependable strength and durability in demanding threaded piping installations.
Threaded End Closure
The internal female NPT connection threads over a compatible male-threaded pipe end to create a secure termination point.
Class 300 Design
The heavier Class 300 construction is intended for more demanding threaded piping applications than standard Class 150 malleable iron fittings.
Why Use a 300# Pipe Cap?
Secure Pipe Termination
A threaded cap provides a straightforward way to close the end of a pipe run for system completion, maintenance, testing, isolation, or future expansion.
Serviceable Closure
Because the cap is threaded, it can generally be removed later when access to the pipe end is required, provided the system is safely isolated and depressurized first.
Typical Applications
Industrial & Mechanical Piping
- Industrial piping systems
- Mechanical piping
- Compressed air systems
- Equipment piping
- General fluid piping
Common Service Applications
- Gas piping
- Oil piping
- Air lines
- Utility piping
- Higher-duty threaded systems
Ask Willy: Need Pipe Size Help?
Use our common pipe diameters and wall thickness chart to confirm sizing before ordering 300# black malleable iron fittings. You can also review the cap specification sheet and Certificate of Conformance below.
Standards & Approvals
ASTM A197
Malleable iron castings conform to ASTM A197.
ASME Standards
Malleable fitting dimensions conform to ASME B16.3, while NPT threads conform to ASME B1.20.1.
UL Listing
The supplied product information states that Class 300 malleable iron fittings are UL Listed.
Related Malleable Iron Standards
- Malleable bushings, plugs, and locknuts conform to ASME B16.14.
- Malleable unions conform to ASME B16.39.
- NPT threads on applicable fittings conform to ASME B1.20.1.
- Class 300 fittings are UL Listed according to the supplied product information.
Need More 300# Black Malleable Iron Fittings?
Browse our complete selection of 300# black malleable iron fittings, including caps, elbows, street elbows, tees, couplings, bushings, unions, and other heavy-duty threaded fittings.
Frequently Asked Questions
What is a 300# black malleable iron cap used for?
It is used to close the end of a compatible male-threaded pipe in a higher-duty threaded piping system.
What type of connection does this cap use?
The cap uses an internal female NPT threaded connection.
What is the difference between a pipe cap and a pipe plug?
A cap has female threads and installs over a male-threaded pipe end. A plug has male threads and installs into a female-threaded opening.
Can this cap be used for future expansion points?
Yes. Threaded caps are commonly used to temporarily close pipe ends that may later be reopened for system expansion or modification.
Can the cap be removed later?
Yes. The threaded design allows removal when needed, provided the piping system has first been safely isolated and depressurized.
How is a 300# cap different from a 150# cap?
The Class 300 fitting is a heavier-duty fitting intended for more demanding threaded piping applications than a standard Class 150 fitting.
What material standard applies?
The supplied product information states that the malleable iron castings conform to ASTM A197.
What dimensional standard applies?
Malleable fitting dimensions conform to ASME B16.3.
What thread standard applies?
NPT threads conform to ASME B1.20.1.
Are Class 300 malleable iron fittings UL Listed?
Yes. The supplied product information states that Class 300 fittings are UL Listed.
Important Ordering & Installation Notes
- Confirm the required nominal pipe size before ordering.
- This cap uses a female NPT connection and is designed for a compatible male-threaded pipe end.
- Do not confuse a cap with a plug; caps are female threaded while plugs are male threaded.
- Confirm that Class 300 construction is appropriate for the intended piping system.
- NPT threads conform to ASME B1.20.1.
- Malleable fitting dimensions conform to ASME B16.3.
- Use compatible pipe, fittings, thread sealant, and accepted threaded installation practices.
- Depressurize and isolate the piping system before removing an installed cap.
- Do not assume the “300#” class designation alone establishes allowable working pressure for every service condition.
- Verify pressure, temperature, media compatibility, applicable codes, and system requirements before installation.
- Refer to the specification sheet and Certificate of Conformance for additional product information.
