Wye, PVC Schedule 80 4" x 3" (875-422)

The 4" x 3" PVC Schedule 80 Wye (Part No. 875-422) is a heavy-duty, three-port branch fitting that combines a 4-inch mainline run with a 3-inch reduced branch outlet joined at a 45-degree angle — delivering the hydraulic efficiency of wye geometry alongside the increased wall thickness, higher pressure capacity, and superior mechanical resilience that define Schedule 80 construction. All three ports are slip (socket) end, accepting PVC pipe or spigot fittings via solvent-weld connection for a permanent, high-integrity joint across all three legs of the system.

At this size pairing, the 4" x 3" wye occupies a common and well-established position in mid-size pressure and drainage piping. The 4-inch mainline run is one of the most frequently specified pipe sizes across commercial, industrial, and municipal systems — large enough to handle meaningful flow volumes in process headers, force mains, and distribution laterals, yet compact enough to appear throughout mechanical rooms, equipment vaults, and site piping layouts where physical space is a real design constraint. The 3-inch branch outlet represents a near-full-bore reduction — stepping down just one nominal pipe size from the mainline — making this wye the correct specification when nearly the full flow capacity of the mainline must be available through the branch, whether that branch feeds a downstream sub-system, a parallel circuit, or a gravity-flow lateral connection.

The 45-degree branch geometry is the hydraulic and design advantage that sets a wye apart from a standard tee at any diameter. A tee redirects branch flow perpendicular to mainline travel — a sharp 90-degree momentum change that generates turbulence, increases head loss, and in gravity-flow systems creates conditions favorable to solids deposition and blockage at the junction. A wye eases branch flow in the direction of mainline travel at a 45-degree angle, producing a smoother, lower-turbulence transition between the run and the branch that reduces head loss, improves self-cleaning characteristics in drain and sewer applications, and better preserves flow balance in pressure systems with multiple branch points. In sanitary sewer, stormwater, and industrial drainage applications, the 45-degree wye is frequently specified by design standards for lateral and service connections precisely because of these hydraulic characteristics — and at 4" x 3", this fitting serves those applications in the size range most common to commercial building drainage, industrial process drain systems, and municipal sewer laterals.

Specifying this fitting in Schedule 80 rather than Schedule 40 reflects an engineering judgment about the service demands of the installation — whether driven by operating pressures that exceed Schedule 40 design limits at this diameter, chemical fluid service that benefits from the greater wall mass of Schedule 80, mechanical loading or impact resistance requirements at an exposed or structurally loaded branch junction, or a system-wide Schedule 80 specification in a high-criticality process piping or industrial drainage installation. The thicker PVC wall of Schedule 80 delivers a higher pressure rating than Schedule 40 at equivalent diameters, greater resistance to impact and external mechanical stress, and improved structural integrity under thermal cycling in continuous-duty service environments.

Manufactured from virgin PVC compound to ASTM D2467 standards and gray in color per Schedule 80 convention, this wye is NSF/ANSI 61 certified for potable water contact — qualifying it for municipal water distribution, water treatment infrastructure, and food-adjacent process piping in addition to its core industrial, chemical, and wastewater applications. Compatible with IPS-standard PVC solvent cements and primers for a code-compliant, permanent installation.

Specifications:

Note: Schedule 80 pressure ratings exceed Schedule 40 at equivalent diameters due to increased wall thickness. Always consult manufacturer-published pressure-temperature rating tables for the specific size and service conditions before system design.

Industries & Applications:

• Industrial Process Piping — The core Schedule 80 application at this size; used at branch junctions in chemical plants, pharmaceutical facilities, refineries, and heavy manufacturing environments where a 4-inch process header must branch to a near-full-bore 3-inch sub-process line, equipment drain, or parallel circuit connection under operating pressures or chemical service conditions that exceed Schedule 40 design limits
• Chemical Handling Systems — Schedule 80's increased wall thickness and structural integrity make this wye well-suited to service where a 4-inch chemical supply or process main must introduce a 3-inch branch connection; the near-full-bore reduction ratio preserves strong flow capacity through the branch in dosing, transfer, and recirculation applications; always verify chemical compatibility with the specific fluid and concentration before specification
• Wastewater & Sanitary Sewer Systems — The 45-degree branch geometry aligns with sanitary sewer design standards for lateral and service connections in gravity-flow drain systems; the Schedule 80 specification extends this fitting's range into pressurized force main and pump station discharge applications where pump discharge pressure at 4-inch diameter requires the higher wall strength of Schedule 80 at the branch junction
• Industrial Drainage & Process Drain Systems — Used in chemical-resistant floor drain headers, equipment drain manifolds, and process drain collection systems in industrial facilities where corrosive or aggressive drain fluids, elevated temperatures, or mechanical loading at the branch fitting justify Schedule 80 specification over standard Schedule 40 drainage fittings
• Municipal Water Distribution — Specified in high-pressure service zones, meter vault configurations, and engineered service lateral designs where a 3-inch branch lateral must be introduced off a 4-inch distribution main with the pressure margin and structural performance of Schedule 80 over standard Schedule 40 at this diameter
• Water Treatment & Filtration Plants — Integrates into 4-inch process piping headers and treatment train distribution systems where a near-full-bore 3-inch branch connection is required in plant environments where Schedule 80 is specified for pressure capacity, chemical resistance, or long-term reliability in continuous-duty treatment service
• High-Pressure Irrigation & Pump Stations — Specified on pump discharge manifolds and pressurized mainline laterals in commercial and agricultural irrigation systems where operating pressures at 4-inch diameter exceed Schedule 40 design limits and where the 45-degree branch geometry is preferred for its lower head loss contribution at the zone distribution junction
• Aquaculture & Recirculating Systems — Used in RAS distribution manifolds and tank supply networks where a 4-inch process header branches to a 3-inch zone feed or tank supply line in a continuous-duty facility environment where Schedule 80 is specified for long-term joint integrity and flow reliability across the distribution system