Metal-fab 4MSC Storm Collar 4 Inches B-vent

Product Description

The METAL-FAB 4MSC is a 4-inch storm collar designed for use with double-wall B-vent pipe systems. Storm collars seal the gap between a vent pipe and the roof penetration, preventing water infiltration at the flashing point. This metal collar is a standard component in gas appliance venting installations and is typically installed by licensed HVAC technicians or plumbers completing a venting system. At approximately 1 pound, the 4MSC is a lightweight, direct-fit solution for 4-inch B-vent pipe runs.

This storm collar is suited for residential and light commercial gas appliance venting where B-vent double-wall pipe exits through the roof. Common applications include venting for gas furnaces, water heaters, and boilers that use Type B gas vent pipe. It is installed at the roof deck where the vent pipe passes through the roofline, seating against the flashing to create a weather-tight barrier.

Key Features

• Fits 4-inch double-wall B-vent pipe systems
• Metal construction for durable, long-term performance in outdoor roof penetration applications
• Seals the vent-to-flashing gap to prevent moisture intrusion
• Lightweight at approximately 1 pound for easy single-tech installation
• Standard OEM-style sizing for compatibility with B-vent pipe runs

Compatibility

Designed as an OEM-style replacement or new-installation storm collar for 4-inch double-wall Type B gas vent pipe systems in residential and light commercial venting applications.

Installation Notes

Installation should be performed by a licensed HVAC technician or plumber in accordance with the International Fuel Gas Code (IFGC) and the appliance manufacturer's venting requirements. Shut down and allow the appliance and vent pipe to cool before handling any vent components. Slide the storm collar over the pipe before seating it against the roof flashing, and seal per local code requirements. Do not install on vent pipe sizes other than those specified.