4 inch Mushroom Vent Cap with Set Screw

Fox Foundry 4 inch Mushroom Vent Cap with Set Screw – Built for Functional System Ventilation

The 4 inch Mushroom Vent Cap with Set Screw is engineered to support proper venting in plumbing systems by allowing consistent airflow while minimizing the intrusion of debris. Designed for durability and performance in outdoor environments, this fitting is a practical solution for long-term reliability in both residential and commercial installations.

Constructed from high-strength polymer, the cap resists UV degradation and corrosion, making it suitable for exposure to rooftop or wall-vented configurations. Its set screw feature ensures secure installation, even in high-wind zones or vertical vent runs.

Performance Features

Effective venting hardware helps maintain system balance and extend the lifespan of connected components. The Fox Foundry vent cap provides the following contractor-grade benefits:

• ✅ Secure Attachment – Set screw connection provides a stable, non-slip fit on 4 inch vent stacks.
• ✅ Weather-Resistant Design – Made to handle freeze-thaw cycles, direct sunlight, and precipitation without performance loss.
• ✅ Ventilation Efficiency – Mushroom-style hood optimizes airflow while deterring leaves, birds, and debris from obstructing the pipe.

Specifications

• Nominal Size: 4 inches
• Material: UV-stabilized plastic
• Mounting: Set screw for mechanical retention on pipe
• Application: DWV (Drain-Waste-Vent) systems
• Standards Compliance: Meets applicable codes for vent terminal devices

Common Applications

Used to cap open vertical vent pipes, particularly in roof venting configurations, this product helps prevent system pressure imbalances caused by blocked or restricted vents. It is suitable for both new installations and code-compliant system upgrades.

System Design Note

Proper vent terminal components such as this cap help mitigate siphoning of traps and backpressure in DWV networks. They also serve as passive barriers against nesting animals and large particulate intrusion without impeding required vent flow.

Summary of Benefits

• ✅ Form-Fitted Design – Mushroom profile reduces wind resistance and promotes uniform discharge.
• ✅ Durable Polymer Body – Corrosion-free and impact-resistant for long service life.
• ✅ Tool-Free Maintenance – Simple to inspect or remove during scheduled system access.