Royal Building Products 35-1640 Gasketed Sewer Coupling

Product Description

The ROYAL BUILDING PRODUCTS 35-1640 is a gasketed sewer coupling increaser designed for DR35 PVC sewer piping systems. This fitting connects a 6-inch pipe to a 4-inch pipe, allowing transitions between two common sewer line sizes within a buried gravity-flow drainage system. The integrated gasket provides a watertight, root-resistant seal without solvent cement, speeding up installation in the field. It is typically installed by licensed plumbers and utility contractors working on residential or light commercial underground sewer laterals.

This increaser coupling is suited for underground sewer and drain applications where DR35 thin-wall PVC pipe is specified. It handles the transition from a larger-diameter main or stub-out down to a smaller lateral or branch run. The gasketed joint style is common in municipal-style sewer work and meets typical gravity sewer installation standards. It is appropriate for use in residential sewer laterals and site utility drain lines operating under gravity flow conditions.

Key Features

• Gasketed joint eliminates solvent cement for faster field assembly
• Increaser design transitions from 6-inch to 4-inch pipe diameter
• Engineered for DR35 PVC sewer pipe compatibility
• Watertight gasket seal resists root intrusion and groundwater infiltration
• Suitable for gravity-flow underground sewer and drain service

Compatibility

Designed as an OEM-style replacement fitting for DR35 PVC gasketed sewer systems using 6-inch by 4-inch increaser couplings in underground gravity drain applications.

Installation Notes

Installation is performed by a licensed plumber or utility contractor following applicable local plumbing codes and IPC requirements for underground sewer piping. Inspect the gasket for damage or debris before assembly and lubricate per manufacturer guidelines to ensure a proper seal. Ensure the pipe ends are cut square, deburred, and clean before insertion. Do not over-drive the pipe past the home mark, as this can distort the gasket and compromise the joint.