Tee, Slip x Slip x FPT PVC Schedule 80 4" x 2-1/2" (802-421)

The 4" x 4" x 2-1/2" PVC Schedule 80 Tee (Slip x Slip x FPT) is a mixed-connection reducing tee engineered for industrial PVC piping systems that require a moderate-sized, threaded branch takeoff from a permanent solvent-weld main run. With 4-inch slip socket connections on both run ends and a 2-1/2-inch female NPT threaded connection on the branch outlet, this fitting combines a size reduction and a connection type transition in a single fitting body — the 4-inch slip run installs permanently into the piping system via solvent cement, while the 2-1/2-inch FPT branch accepts any standard male NPT fitting for a threaded, serviceable connection that can be broken and reassembled without disturbing the cemented main.

The 2-1/2-inch branch positions this fitting as the middle option in the 802-series Slip x Slip x FPT tee line — stepping between the smaller 2-inch FPT branch of the 802-420 and the larger 3-inch FPT branch of the 802-422. This is not a splitting-the-difference specification: 2-1/2 inches is a distinct nominal pipe size with its own flow characteristics, fitting ecosystem, and application profile. A 2-1/2-inch branch carries meaningfully more flow capacity than a 2-inch branch while remaining smaller than a 3-inch lateral — making it the appropriate specification in systems where the branch demand exceeds what a 2-inch connection can handle but where a full 3-inch branch would be oversized relative to the downstream requirement.

In practice, 2-1/2-inch branches appear most frequently in medium-flow pump bypass lines, moderate-capacity chemical feed systems, secondary distribution laterals serving a defined equipment cluster, and branch connections to 2-1/2-inch valves or strainers where a 2-inch connection would create a flow bottleneck and a 3-inch connection would require an unnecessary reducer downstream. The female NPT thread on the branch accepts any standard 2-1/2-inch male NPT fitting directly — a ball valve, a union, a strainer, a pressure gauge assembly, or a threaded nipple — without requiring a separate adapter in the branch line.

Schedule 80 PVC provides the elevated wall thickness required for industrial service throughout the fitting body, and at the FPT branch specifically, the additional material depth supports greater thread engagement and improved resistance to thread fatigue under cycling pressure loads compared to a Schedule 40 equivalent. All run connections are designed for solvent cement installation per ASTM D2564 procedures. Manufactured to ASTM D2467 standards and compatible with Schedule 80 PVC pipe on the run ends and standard NPT threaded fittings on the branch.

Specifications:

Industries & Applications:

• Pump Bypass & Recirculation Lines — The 2-1/2-inch branch provides adequate flow capacity for pump bypass, recirculation, or pressure relief connections on 4-inch industrial systems where a 2-inch branch would restrict flow and a 3-inch branch would be oversized relative to the bypass circuit's demand
• Chemical Processing & Feed Systems — Specified in chemical-resistant 4-inch process headers where a 2-1/2-inch threaded branch connects a moderate-capacity chemical feed line, transfer connection, or secondary process supply that exceeds the flow range of a 2-inch branch
• Water & Wastewater Treatment — Applied in treatment plant process piping where 4-inch Schedule 80 mains require a 2-1/2-inch threaded branch for filter connections, chemical dosing headers, or secondary distribution to a defined cluster of treatment equipment requiring more than a 2-inch supply
• Strainer & Filter Connections — Used at branch points where a 2-1/2-inch strainer or inline filter is installed on the branch line — a common size in industrial strainer assemblies — and a threaded FPT connection provides the direct, serviceable interface the strainer requires for cleaning and element replacement
• Industrial Process Piping & Manifolds — Incorporated in process plant pipe racks and manifold assemblies where a 2-1/2-inch FPT branch provides a moderate-capacity secondary outlet from a 4-inch primary header, with the threaded connection allowing the branch valve or fitting to be replaced without disturbing the cemented main
• Irrigation & Agricultural Infrastructure — Specified in 4-inch Schedule 80 irrigation mains where a 2-1/2-inch threaded branch connection serves a filter station, pressure regulator assembly, or zone valve body that is sized for 2-1/2-inch flow capacity and requires a threaded interface for routine seasonal maintenance