Charman Inc.
150# Black Malleable Iron Square Head Plug
- Availability:
- Usually in Stock – Ships Quickly
- Weight:
- 0.00 LBS
Description
150# Black Malleable Iron Square Head Plug
150# black malleable iron square head plugs are designed to close and seal female-threaded openings in black iron pipe fittings, valves, manifolds, and other compatible piping components. The male NPT connection threads directly into a matching female NPT opening, while the raised square head provides a positive wrenching surface for installation and removal.
Select the required nominal pipe size from the product options above. The selected variation determines the Charman item number, online selling price, weight, cost, and other size-specific product information.
Product Highlights
- 150# Class black malleable iron construction
- Male NPT threaded connection
- Raised square head for wrench installation and removal
- Designed to close unused female-threaded pipe openings
- Durable black finish
- Compatible with standard black malleable iron fittings and threaded piping components
- Available in nominal pipe sizes from 1/8" through 6"
- Suitable for commercial, industrial, maintenance, and repair applications
Technical Specifications
| Material | Black Malleable Iron |
|---|---|
| Pressure Class | 150# / Class 150 |
| Connection | Male NPT |
| Head Style | Square Head |
| Thread Standard | ASME B1.20.1 |
| Finish | Black |
| Fitting Type | Threaded Pipe Plug |
| Manufacturer | Charman Manufacturing |
| Available Sizes | 1/8" through 6" |
How a Square Head Plug Works
The male NPT threads on the plug engage a matching female NPT opening in a fitting, valve, manifold, or other piping component. As the tapered threads tighten, an approved thread sealant helps create a secure seal. The square head provides flat wrenching surfaces for controlled tightening and later removal when service access is required.
Common Applications
Piping and Mechanical Systems
- Closing unused fitting outlets
- Sealing threaded test ports
- Temporary or permanent pipe-system closures
- Mechanical-room piping
- Black steel pipe installations
- General repair and maintenance
Industrial and Utility Service
- Industrial process piping
- Compressed-air systems
- Natural-gas piping
- Water and utility piping
- Oil and petroleum piping
- Approved low-pressure steam service
Product Resources
Review the Charman product catalog, Class 150 specifications, and manufacturer warranty information before installation.
Need Help Selecting a Black Malleable Iron Square Head Plug?
Our industrial PVF specialists can help confirm the required pipe size, pressure class, thread type, material compatibility, application requirements, and product availability.
Frequently Asked Questions
What is a black malleable iron square head plug used for?
A square head plug is used to close and seal an unused female-threaded opening in a pipe fitting, valve, manifold, or other compatible piping component.
Does this plug have male or female threads?
This plug has male NPT threads and installs into a matching female NPT opening of the same nominal pipe size.
Why does the plug have a square head?
The raised square head provides flat wrenching surfaces that make the plug easier to tighten, loosen, and remove during maintenance or system changes.
What pressure class is this fitting?
This black malleable iron square head plug is manufactured as a 150# or Class 150 threaded fitting.
What sizes are available?
Available product variations range from 1/8" through 6" nominal pipe size. Select the required size from the product options above.
Can this plug be used with black malleable iron fittings?
Yes. It is designed to thread into compatible female NPT openings in black malleable iron fittings and other approved threaded piping components.
Can it be used for gas, water, oil, air, or steam?
It may be used in compatible gas, water, oil, compressed-air, steam, and general-service systems when the application remains within applicable pressure, temperature, media, code, and manufacturer requirements.
Should thread sealant be used during installation?
Yes. Use an approved pipe-thread sealant or thread tape selected for the piping media, pressure, temperature, applicable codes, and manufacturer recommendations.
Can the plug be removed later?
Yes. The square head is designed to provide a secure wrenching surface for later removal, provided the plug is accessible and has not been damaged, over-tightened, or permanently secured.
How tight should a square head plug be installed?
Install it securely using proper tools and approved sealant, but avoid excessive torque that could damage the plug, mating fitting, or threads. Follow applicable codes and manufacturer recommendations.
Important Ordering Notes
- Select the required nominal pipe size before adding the product to your cart.
- The selected variation determines the Charman item number, price, weight, and cost.
- This product has male NPT threads and requires a compatible female NPT opening.
- Confirm the nominal size and thread type of the mating component before ordering.
- Use an approved thread sealant suitable for the piping media and operating conditions.
- Confirm pressure, temperature, media compatibility, and application requirements before installation.
- Do not over-tighten the plug, as excessive torque may damage the threads or mating fitting.
- Installation should be completed by qualified personnel and comply with applicable codes and standards.
- Manufacturer warranty coverage is subject to the terms, limitations, and exclusions in the linked warranty document.
