Selkirk 104307 Rv Increaser 4 to 7 Inch B-vent

Product Description

The SELKIRK 104307 is a Type B gas vent increaser fitting designed to transition a 4-inch diameter vent pipe to a 7-inch diameter vent pipe within a residential or light commercial venting system. This component is part of the RV Series B-vent product line and is used when a vent run requires a step-up in pipe diameter, typically to maintain proper draft or to connect into a larger common vent trunk. Licensed HVAC technicians and plumbers install this fitting during new construction and replacement venting projects on gas-fired appliances.

This increaser is applied in Type B double-wall gas vent systems serving natural gas or propane appliances such as furnaces, water heaters, and boilers. The 4-inch inlet connects to the smaller vent section leaving the appliance or an upstream fitting, while the 7-inch outlet connects to the larger downstream vent or common connector. It is suited for residential installations and light commercial applications where NFPA 54 and local mechanical codes govern vent sizing and configuration.

Key Features

• Transitions vent diameter from 4 inches to 7 inches in a single fitting
• Designed for Type B double-wall gas vent systems
• Part of the SELKIRK RV Series for consistent system compatibility within the product line
• Supports proper draft by accommodating required vent diameter changes along the run
• Manufactured for use with natural gas and propane appliance venting

Compatibility

Designed as an OEM-style component for use within SELKIRK RV Series Type B double-wall gas vent systems requiring a 4-inch to 7-inch increaser transition fitting.

Installation Notes

Installation must be performed by a qualified HVAC technician or plumber in accordance with NFPA 54, the appliance manufacturer instructions, and local mechanical codes. Shut off the gas supply and allow the appliance to cool completely before disassembling any vent sections. Ensure all joints are fully engaged and secured per the manufacturer assembly method for the RV Series system. Do not mix vent system components from different manufacturers within the same vent run.

Technical Specifications

• Inlet Diameter: 4 inches
• Outlet Diameter: 7 inches
• Vent Type: Type B Double-Wall Gas Vent
• Series: RV Series
• Fitting Type: Increaser

Standard Information

• Brand: SELKIRK
• Manufacturer Part Number: 104307