Difference Between NPT PVC Male Threaded Plug and Female Cap

1. Thread Orientation

Male Threaded Plug:
- Features external threads (male) to screw into a fitting with internal threads (female).
- Seals the end of a pipe or fitting, effectively blocking flow at that point.
Female Cap:
- Has internal threads (female) to fit over a pipe or fitting with external threads (male).
- Covers and seals the open end of a male-threaded pipe or fitting.

2. Application

Male Threaded Plug:
- Used to block off unused outlets or openings on fittings like tees or couplings.
- Common in systems that may require future expansion or temporary sealing during maintenance.
Female Cap:
- Designed to cover the open end of a male-threaded pipe or fitting, sealing it for protection or flow stoppage.
- Often used in capping off pipe ends to protect threads and prevent debris or contamination.

3. Design Differences

Male Threaded Plug:
- Compact design with external threads only.
- Typically has a square or hex head for easy tightening or removal with tools.
Female Cap:
- Larger, cylindrical design with internal threading.
- May feature a flat or rounded top for aesthetic and functional sealing.

4. Common Use Cases

Feature	Male Threaded Plug	Female Cap
Primary Use	Block off openings in fittings	Cap off pipe ends or male-threaded fittings
Thread Location	External threads	Internal threads
Tools Required	Wrench or pliers for tightening/removal	Often hand-tightened but may require a wrench for snug fit
Applications	Unused ports, temporary seals	End-caps for pipes, thread protection

5. Material and Standards

Both components are typically made from durable PVC and conform to NPT (National Pipe Thread) standards, ensuring compatibility with other NPT-threaded components.

Summary

While both fittings serve the purpose of sealing pipes, their orientation and use cases differ. Choose a male threaded plug for blocking ports on fittings and a female cap for covering open pipe ends. Both are essential for versatile, leak-proof piping systems.