Reducer Coupling, Slip x Slip PVC Schedule 80 4" x 3" (829-422)

The 4" x 3" PVC Schedule 80 Reducing Coupling (829-422) provides a direct, inline size transition from a 4" primary line down to a 3" continuation run — in a single solvent-welded fitting, without intermediate reducers, bushings, or additional fittings at the transition point. Both ends use slip (socket) connections for permanent, pressure-rated joints that maintain the full structural integrity of a Schedule 80 gray PVC assembly throughout.

The 4" to 3" step-down is a moderate, single-increment reduction — one of the most common inline diameter transitions in commercial and industrial PVC piping systems. Where the sharper 4" x 2" reduction of the 829-420 suits applications requiring a significant flow restriction at the transition, the 829-422 is the right choice when the secondary run must still carry substantial flow volume, with only a controlled reduction in pipe diameter from the primary header. This makes it a practical fit for process headers, distribution manifolds, and mechanical system mains where a gradual, engineered step-down is specified rather than an abrupt size change.

Manufactured to Schedule 80 specifications and dimensionally compliant with ASTM D2467, the 829-422 delivers the elevated wall thickness and increased pressure rating that Schedule 80 gray PVC is specified for in chemical processing, industrial fluid handling, and demanding commercial applications. Gray PVC construction provides broad chemical compatibility with acids, alkalis, and a wide range of industrial process fluids where white Schedule 40 PVC is not appropriate. NSF 61 certification confirms suitability for potable water contact where required.

Specifications:

Industries & Applications:

• Chemical Processing — controlled inline size reductions on chemical feed, dosing, and process fluid distribution headers where a moderate single-step diameter reduction to a 3" secondary run is required
• Industrial Process Piping — primary-to-secondary line reductions in plant utility, cooling water, and recirculating process systems requiring Schedule 80 pressure and chemical performance
• Water & Wastewater Treatment — inline reducing connections in treatment plant process piping where a single-increment diameter step-down is specified and Schedule 80 is required for pressure or chemical compatibility
• Commercial & Industrial Plumbing — header-to-distribution inline reductions in high-pressure mechanical systems where Schedule 40 pressure ratings are insufficient for the application
• Aquaculture & Food Processing — corrosion-resistant inline size transitions in recirculating systems and sanitary or chemical-exposure fluid handling installations
• Irrigation & Agriculture — mainline-to-distribution inline reductions in high-pressure irrigation and chemical injection systems where a moderate, single-step flow reduction is engineered into the system design