Service Metal
300# Galvanized Malleable Caps
- SKU:
- XGCP
- Availability:
- Usually Ships Same Day
- Weight:
- 0.00 LBS
Description
300# Galvanized Malleable Iron Cap
300# Galvanized Malleable Iron Caps are designed to securely close the ends of threaded pipe in higher-duty piping systems where added corrosion resistance is required.
Manufactured from durable malleable iron with a hot-dip galvanized finish, these Class 300 caps provide dependable strength and corrosion protection for plumbing, waterworks, HVAC, mechanical, industrial, and outdoor piping applications exposed to moisture, humidity, and demanding service conditions.
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 system testing, isolation, maintenance, and future expansion
- Hot-dip galvanized finish for added corrosion resistance
- Durable malleable iron construction
- Malleable castings conform to ASTM A197
- Hot-dipped galvanized fittings conform to ASTM A153
- Malleable fitting dimensions conform to ASME B16.3
- NPT threads conform to ASME B1.20.1
- Class 300 fittings are UL Listed
- Suitable for water, air, HVAC, mechanical, and outdoor applications
- Approved to ANSI/NSF 61-4 Annex G and CA AB1953 (<0.25% lead)
- Manufactured in an ISO-certified facility
- Country of origin: Thailand & China
Technical Specifications
| Product Type | Pipe Cap |
|---|---|
| Material | Malleable Iron |
| Finish | Hot-Dip Galvanized |
| Pressure Class | 300# |
| Connection Type | Female NPT |
| Configuration | Threaded End Closure |
| Primary Function | Seal / Terminate Male-Threaded Pipe |
| Casting Standard | ASTM A197 |
| Galvanizing Standard | ASTM A153 |
| Dimensional Standard | ASME B16.3 |
| Thread Standard | ASME B1.20.1 |
| Listing | Class 300 Fittings are UL Listed |
| Lead / Potable Water Compliance | ANSI/NSF 61-4 Annex G and CA AB1953 (<0.25% lead) |
| 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 systems.
Threaded End Closure
The internal female NPT connection threads over a compatible male-threaded pipe end to create a secure termination point.
Hot-Dip Galvanized Finish
The galvanized coating conforms to ASTM A153 and provides added protection against rust and corrosion in moisture-prone and outdoor environments.
Why Use a 300# Galvanized Pipe Cap?
Secure Pipe Termination
A threaded cap provides a straightforward way to close the end of a pipe run for system completion, testing, maintenance, isolation, or future expansion.
Added Corrosion Resistance
The hot-dip galvanized coating helps protect the fitting in environments exposed to moisture, humidity, weather, and other conditions where bare black iron may be less suitable.
Typical Applications
Mechanical & Commercial Piping
- Mechanical piping systems
- Commercial plumbing
- HVAC piping
- Water distribution
- Compressed air systems
- General utility piping
Galvanized & Outdoor Applications
- Outdoor piping
- Moist environments
- Waterworks installations
- Industrial piping
- System test points
- Future expansion points
Ask Willy: Need Pipe Size Help?
Use our common pipe diameters and wall thickness chart to confirm sizing before ordering 300# galvanized malleable iron fittings. You can also review the cap specification sheet and Certificate of Conformance below.
Standards & Approvals
ASTM Standards
Malleable iron castings conform to ASTM A197, while hot-dipped galvanized fittings conform to ASTM A153.
ASME Standards
Malleable fitting dimensions conform to ASME B16.3, while NPT threads conform to ASME B1.20.1.
UL & Lead Compliance
Class 300 fittings are UL Listed. Galvanized fittings are listed as meeting ANSI/NSF 61-4 Annex G and CA AB1953 requirements in the supplied product information.
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# Galvanized Malleable Iron Fittings?
Browse our complete selection of 300# galvanized malleable iron fittings, including caps, elbows, tees, couplings, bushings, unions, and other heavy-duty threaded fittings.
Frequently Asked Questions
What is a 300# galvanized malleable iron cap used for?
It is used to close the end of a compatible male-threaded pipe in a higher-duty piping system while providing added corrosion resistance from the galvanized finish.
What type of connection does this cap use?
The cap uses an internal female NPT threaded connection.
What is the difference between a cap and a 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 fitting or pipe 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.
Why choose galvanized instead of black malleable iron?
The hot-dip galvanized coating provides added protection against rust and corrosion in piping exposed to moisture, humidity, or outdoor conditions.
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 standard applies to the galvanized coating?
Hot-dipped galvanized fittings conform to ASTM A153 according to the supplied product information.
What thread standard applies?
NPT threads conform to ASME B1.20.1.
Are Class 300 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.
- Hot-dipped galvanized fittings conform to ASTM A153.
- Use compatible galvanized pipe, fittings, and thread sealant appropriate for the intended system.
- Avoid damaging the galvanized coating during handling and installation.
- 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, potable-water requirements, applicable codes, and approval requirements before installation.
- Refer to the specification sheet and Certificate of Conformance for additional product information.
