3 inch Proflex Coupling Connects Cast Iron to PVC, Steel, Extra Heavy Cast Iron

3 Inch Proflex Flexible Coupling – Cast Iron to PVC/Steel

The 3 inch Proflex coupling is a shielded, flexible transition fitting designed for joining dissimilar piping materials—specifically, cast iron, Schedule 40 PVC, and steel—within non-pressurized DWV (Drain, Waste, and Vent) systems. Engineered to provide a mechanical seal using stainless steel clamps and an elastomeric sleeve, this coupling ensures a secure, leak-resistant joint for both new construction and retrofit applications.

Design and Construction Details

• ✅ Stainless Steel Shield – Full 300-series stainless steel band with shear ring provides structural reinforcement and external load distribution.
• ✅ Gasket Material: Flexible elastomeric PVC (meets ASTM C564) ensures long-term sealing under typical DWV service conditions.
• ✅ Clamps: Multiple worm-drive stainless steel clamps per ASTM C1540 provide uniform compression and corrosion resistance.
• ✅ Joint Type: Mechanically sealed – does not require solvent welding or threaded engagement.

Applicable Standards and Certifications

This coupling is tested and listed to meet or exceed the following standards for use in regulated drainage installations:

• ✅ ASTM C1460: For shielded transition couplings
• ✅ UPC Listed: IAPMO certified for use in DWV systems
• ✅ CSA B602: Certified for use in Canada for sanitary waste applications
• ✅ NSF/ANSI 372: Lead-free compliance for potable and non-potable systems

Installation Parameters

Install with a calibrated torque wrench per manufacturer guidelines (typically 60 in-lbs per clamp). Ensure both pipe ends are cut square, deburred, and clean. Insert fully into coupling, center at midline, and tighten all clamps uniformly. Not suitable for pressurized applications or direct burial without proper protection.

Typical Use Cases

This coupling is commonly used in DWV system repairs, remodels, and service line upgrades to transition between different materials, such as adapting cast iron soil pipe to PVC or galvanized steel. It is frequently specified in floor slab penetrations, horizontal drainage branches, and building drain reconnections.

Technical Summary

• Nominal Size: 3 inch
• Pipe Compatibility: Cast Iron, PVC (Sch. 40), Steel
• Seal Type: Mechanical – Shielded with stainless steel clamps
• Service: Gravity-flow DWV systems only

Code Note

This product satisfies requirements for joining dissimilar materials under the International Plumbing Code (IPC) and Uniform Plumbing Code (UPC), when used in accordance with ASTM C1460 and local jurisdictional standards.

The 3 Inch Proflex Coupling provides a durable, code-compliant solution for connecting non-identical piping materials in gravity-flow drainage applications. Designed for long-term mechanical performance, it simplifies installation and eliminates the need for solvent welding or threading during system transitions.