4 inch x 3 inch Proflex Reducing Coupling Connects Copper to Cast Iron, PVC, Steel

4 inch x 3 inch Proflex Reducing Coupling – Flexible Transition for Mixed-Pipe Applications

The 4 inch x 3 inch Proflex Reducing Coupling is engineered for joining pipes of dissimilar materials or sizes, providing a secure, code-compliant connection between 4 inch and 3 inch nominal pipe diameters. Commonly used in DWV systems, this coupling accommodates variations between materials such as cast iron, copper, steel, and schedule-rated plastic piping.

Key Technical Advantages

• ✅ Stainless Steel Shield Features a full 300-series stainless steel band with screw clamps for added strength and resistance to deformation under load.
• ✅ EPDM Gasket Molded to provide a compression seal around both pipe diameters, rated for standard DWV pressure conditions and tested for joint integrity.
• ✅ Corrosion Resistance All metal components are designed to withstand corrosive conditions in both above-ground and underground environments.
• ✅ Multi-Material Compatibility Connects copper, cast iron, PVC, ABS, and steel piping without the need for specialty transitions or bushings.
• ✅ Conforms to Standards Manufactured to comply with ASTM C1460 and CSA B602 performance requirements.

Installation Considerations

Use a torque wrench to tighten stainless steel clamps to the manufacturer-specified torque, typically 60 in-lbs. Surface preparation must include removing scale or debris from the pipe ends. Ensure pipe ends are square-cut and fully inserted into the gasket before final tightening.

Application Scope

This reducing coupling is commonly installed in residential and light commercial plumbing systems where size transitions are required—particularly during renovations or when integrating modern plastic piping with legacy cast iron or copper systems.

Specifications

• Size: 4 inch x 3 inch
• Gasket Material: EPDM
• Shield and Clamp: Type 300 series stainless steel
• Pressure Rating: Designed for non-pressure DWV systems
• Certifications: ASTM C1460, CSA B602

For contractors working with mixed-material systems or retrofitting older installations, the 4 inch x 3 inch Proflex Reducing Coupling offers a straightforward and compliant solution to ensure structural integrity and leak resistance across varying pipe standards.