4 inch x 3 inch ABS DW Reducing Coupling Plastic x Plastic

4 inch x 3 inch ABS DWV Reducing Coupling – Hub x Hub

The 4 inch x 3 inch ABS DWV Reducing Coupling is a solvent-weld fitting designed to connect different pipe diameters in non-pressurized drain, waste, and vent (DWV) systems. It enables a secure transition from 4-inch to 3-inch nominal pipe size, maintaining system integrity in gravity drainage applications.

Material and Configuration

• ✅ Material: Acrylonitrile Butadiene Styrene (ABS), black, non-metallic, rigid thermoplastic
• ✅ Connection Type: Hub x Hub – designed for solvent cement joining to ABS pipe
• ✅ Use: Suitable for horizontal and vertical DWV pipe size transitions
• ✅ Dimensions: One end accepts 4 inch DWV pipe; the other end accepts 3 inch DWV pipe

Performance Standards

• System Type: DWV (drain, waste, and vent) – gravity flow only
• Applicable Standards: Conforms to ASTM D2665 and CSA B181.1
• Temperature Rating: Up to 140°F (60°C) for intermittent flow in non-pressure systems
• Installation Method: Solvent-weld using approved ABS cement (primer not required for ABS in most jurisdictions)

Installation Guidance

Prepare pipe ends by cutting square and removing burrs. Apply ABS solvent cement to both pipe and fitting surfaces. Insert pipe fully into hub and hold until set. Allow cure time per manufacturer's instructions prior to testing or backfilling. Ensure alignment and sizing are confirmed prior to solvent-welding.

Common Applications

• Residential and light commercial DWV systems
• Vertical stack to branch line size reductions
• Connection of fixtures requiring 3 inch discharge to a 4 inch main waste line
• Retrofit projects and DWV system modifications

Material Characteristics

ABS is known for its impact resistance, lightweight structure, and resistance to degradation in cold-weather environments. It is commonly selected for above-grade and in-wall DWV installations and is suitable for use in climates where temperature variations are common.

The 4 inch x 3 inch ABS DWV Reducing Coupling offers a durable, code-compliant method for joining dissimilar pipe sizes within solvent-welded drainage systems. Its dimensional stability and chemical resistance support long-term performance in gravity-flow wastewater installations.