Reducer Coupling, Slip x Slip PVC Schedule 40 3" x 2" (429-338)

The 429-338 is a 3" x 2" PVC Schedule 40 reducer coupling in a slip x slip configuration, providing a straight inline size reduction from a 3" pipe or fitting down to a 2" pipe or fitting via solvent cement bonding at both ends. The larger 3" slip socket accepts standard 3" pipe or a spigot-end fitting, while the 2" slip socket transitions the line down to the smaller diameter — in a compact, inline profile with no elbows, offsets, or directional changes.

At a two-step size reduction — 3" down to 2" — the 429-338 handles a meaningful cross-sectional area change at the transition point. This fitting is the appropriate choice when a 3" supply header or mainline must connect to a 2" distribution circuit, equipment inlet, or downstream run where the reduced diameter is dictated by system design, equipment port sizing, or flow capacity requirements downstream of the transition. Consolidating this reduction into a single fitting rather than stepping down through intermediate sizes keeps the assembly compact and minimizes joint count along the run.

The all-slip design bonds both ports permanently with solvent cement, producing a clean, monolithic inline joint with no mechanical connections, threaded interfaces, or O-rings to maintain. At the 3" scale, the permanence of the solvent-weld joint carries particular value — eliminating mechanical joint interfaces in large-diameter piping reduces potential failure points in high-flow systems. This makes the 429-338 well-suited for buried infrastructure, enclosed mechanical spaces, and any large-diameter installation where long-term joint integrity is a priority.

Schedule 40 PVC provides the pressure ratings and chemical resistance appropriate for the broad range of commercial, agricultural, and industrial applications this reducer coupling serves — at a cost-effective wall thickness suited for systems where the higher pressure ratings of Schedule 80 are not required. The white color is the standard identifier for Schedule 40 PVC, distinguishing it clearly from gray Schedule 80 components in mixed systems.

Solvent cement installation follows standard PVC practice — clean, prime, and cement both mating surfaces per ASTM D2564 procedures. At 3" pipe sizes, working efficiently is important — cement one socket at a time and ensure full pipe seating before proceeding. Proper alignment must be confirmed before the cement sets, as socket fits at this diameter leave limited adjustment time once bonded. For 3" joints, use of a heavy-bodied cement is recommended to ensure adequate fill across the larger socket surface.

Specifications:

Industries & Applications:

The 429-338 reducer coupling is used across Schedule 40 systems requiring a permanent, straight inline size reduction from a 3" mainline or header down to a 2" distribution circuit or equipment connection:

• Irrigation & Agriculture — Mainline-to-distribution transitions in large-scale pressurized irrigation systems where a 3" supply header steps down to a 2" zone supply, lateral distribution manifold, or field block supply line in a permanent buried installation
• Water & Wastewater Treatment — Inline size reductions in treatment plant distribution piping, pump station discharge runs, and process water supply lines where a 3" header transitions to 2" downstream piping or equipment connections in a solvent-welded assembly
• Commercial & Industrial Plumbing — Inline reducer connections in cold water supply, equipment feed lines, and mechanical room piping where a 3" building supply or riser transitions to 2" branch distribution circuits in Schedule 40 construction
• Municipal Water Distribution — Straight inline reductions in Schedule 40 PVC water distribution infrastructure where a 3" supply main transitions to a 2" service line, lateral, or secondary distribution run in a permanent buried installation
• Industrial Processing — Two-step inline size reductions at pump discharge transitions, equipment outlet connections, and distribution header-to-circuit interfaces in process piping where a compact solvent-weld reduction from 3" to 2" is required
• Aquaculture & Aquatics — Inline size reductions in large recirculating system headers, pump discharge lines, and filter manifold outlets where a 3" supply transitions to 2" distribution circuits in permanent solvent-weld installations
• Pool & Spa — Inline size transitions in commercial pool mechanical room piping at pump discharge runs, filter outlet connections, and main circulation header-to-distribution transitions where 3" supply lines feed 2" distribution circuits
• HVAC & Cooling Systems — Straight inline reductions in chilled water and process cooling distribution circuits where a 3" supply header transitions to 2" secondary circuit or equipment feed lines in Schedule 40 PVC construction