Reducing Tee, Slip x Slip x FPT PVC Schedule 40 6" x 6" x 4" (402-532)

The 6" x 6" x 4" PVC Schedule 40 Tee (Slip x Slip x FPT) is a large-branch mixed-connection fitting designed for commercial and municipal PVC piping systems that require a high-capacity, threaded branch takeoff from a 6-inch permanent solvent-weld main run. With 6-inch slip socket connections on both run ends and a 4-inch female NPT threaded connection on the branch outlet, this fitting combines a moderate size reduction and a connection type transition in a single fitting body — the 6-inch slip run installs permanently via solvent cement, while the 4-inch FPT branch provides a threaded, serviceable connection point that accepts any standard 4-inch male NPT fitting without additional adapters.

The 4-inch branch is the largest FPT branch size described to date in the 402-series Schedule 40 mixed-connection tee line — and its scale defines the applications it serves. A 4-inch FPT branch off a 6-inch run is not a secondary supply tap, an instrumentation port, or a low-volume lateral. It is a primary branch connection, carrying a substantial portion of the main system's flow capacity to a discrete downstream function that requires both a large connection diameter and a threaded interface. The most characteristic applications are large valve bodies — gate valves, butterfly valves with threaded adapter rings, or large ball valves — installed on the branch for zone isolation or flow control; pump inlet connections where a threaded interface at the pump suction is required; large filter housings with 4-inch threaded inlets; and major lateral takeoffs where a threaded connection is specified for serviceability at a high-capacity branch point.

Compared to the previously described 402-529 (6" x 6" x 2-1/2" FPT branch), the 4-inch branch of this fitting serves a fundamentally different role in the system hierarchy. The 2-1/2-inch branch is a mid-range service connection — filter inlets, gauge assemblies, chemical injectors. The 4-inch branch is a primary lateral — a connection that carries enough flow to serve a substantial downstream circuit, equipment inlet, or zone supply. Selecting between these two fittings is not a matter of preference but of downstream flow demand: the 4-inch branch is specified when the branch circuit's flow requirement exceeds what a 2-1/2-inch or 3-inch connection can deliver, and when the threaded interface at that high-capacity branch point is a design or maintenance requirement rather than an incidental convenience.

The female NPT thread on the branch accepts any standard 4-inch male NPT fitting directly — a gate valve, a ball valve, a butterfly valve adapter, a pump inlet nipple, a union half, or a threaded coupling — without requiring a separate adapter between the tee branch and the downstream component. Thread sealant should be applied to the male-threaded component per standard NPT practice. All run connections install via PVC solvent cement. Manufactured to ASTM D2466 standards and compatible with Schedule 40 PVC pipe on the run ends and standard NPT threaded fittings on the branch.

Specifications:

Industries & Applications:

• Large-Scale Irrigation & Agricultural Systems — The primary commercial application for a 6" x 4" mixed-connection tee; used in 6-inch irrigation mainlines where a 4-inch FPT branch provides a high-capacity threaded connection point for a large zone valve body, pump suction lateral, filter housing inlet, or submain takeoff that requires a full-size threaded interface for installation and routine maintenance without cutting the permanent 6-inch main
• Municipal Water Distribution — Specified in 6-inch municipal distribution mains where a 4-inch threaded branch provides a service connection for a large hydrant lateral, master meter assembly, zone isolation valve, or major service tap requiring a 4-inch threaded interface at the branch point for compliance with threaded connection standards at metered or valved municipal takeoffs
• Pump Suction & Discharge Headers — Incorporated in pump system assemblies where a 4-inch FPT branch on a 6-inch main provides a threaded pump suction inlet connection, recirculation return, or bypass circuit at sufficient flow capacity to serve a high-demand pump circuit — with the threaded interface allowing the pump connection to be broken for service without disturbing the permanent 6-inch run on either side
• Commercial Plumbing & Mechanical Systems — Applied in large commercial building water mains and mechanical room distribution headers where a 6-inch primary supply requires a 4-inch threaded branch for a major secondary circuit, equipment supply connection, or fire suppression system lateral that requires a threaded interface for system testing, maintenance, and compliance inspection
• Water & Wastewater Treatment — Used in treatment plant distribution piping where 6-inch Schedule 40 mains require a 4-inch threaded branch for large filter bypass connections, high-capacity chemical dosing headers, major recirculation circuits, or primary equipment supply lines where flow demand necessitates a full 4-inch branch connection rather than a smaller secondary tap
• Swimming Pool & Aquatics Infrastructure — Specified in 6-inch primary recirculation mains at large commercial aquatic facilities where a 4-inch FPT branch provides a threaded connection point for a major filter inlet, high-capacity backwash line, or primary chemical treatment circuit requiring a large-bore threaded interface at the branch takeoff for routine maintenance and seasonal service access