Reducer Bushing, Spigot x Slip PVC Schedule 40 8" x 4" (437-582)

The 8" x 4" PVC Schedule 40 Reducer Bushing (Spigot x Slip) is a compact inline reducer designed to transition from an 8-inch fitting connection point to a 4-inch downstream pipe run within a single fitting body. The 8-inch spigot end is a plain male outer-diameter that inserts directly into any standard 8-inch Schedule 40 slip socket fitting, while the 4-inch slip socket on the outlet end accepts 4-inch Schedule 40 PVC pipe for permanent solvent cement installation. The result is a two-size step-down — from 8 inches to 4 inches — accomplished entirely within the socket of an existing fitting, without a separate reducer coupling, additional fittings, or extra pipe sections occupying linear space or adding joint count to the assembly.

Within the 437-series 8-inch spigot bushing line now fully described across five small-end sizes — 437-578 (8" x 2"), 437-580 (8" x 3"), 437-582 (8" x 4"), 437-583 (8" x 5"), and 437-585 (8" x 6") — the 8" x 4" configuration occupies the practical midpoint of the series. It is neither the large-differential secondary tap configuration of the 8" x 2" and 8" x 3" bushings nor the near-equivalent primary lateral configuration of the 8" x 5" and 8" x 6" bushings. The two-size step-down from 8 to 4 inches is a balanced, high-utility reduction that appears throughout large-diameter commercial and municipal piping wherever an 8-inch main must supply a 4-inch branch, lateral, or equipment connection — a transition that is common enough across irrigation, municipal water, industrial process, and commercial plumbing applications that the 8" x 4" bushing is likely the highest-demand SKU in the 437-series 8-inch group.

The 4-inch outlet is significant in application terms. Four inches is one of the most widely used nominal pipe sizes in commercial and industrial PVC systems — the standard size for secondary distribution mains, zone supply headers, pump discharge connections, large valve bodies, and equipment inlets across virtually every market segment Maxx-Supply serves. A bushing that transitions from an 8-inch fitting socket to a 4-inch downstream run is therefore a fitting that connects the large-diameter primary infrastructure of a system — 8-inch mains, headers, manifolds — to the medium-diameter distribution and equipment connection layer that delivers flow to its end points. That functional role, at the midpoint between primary infrastructure and working distribution, is what makes the 8" x 4" the most versatile and broadly applicable configuration in the series.

The spigot end is cemented into the receiving 8-inch fitting socket, and the 4-inch slip socket accepts 4-inch Schedule 40 PVC pipe in the standard solvent cement installation procedure. Manufactured to ASTM D2466 standards and compatible with Schedule 40 PVC pipe and fittings in both 8-inch and 4-inch sizes.

Specifications:

Industries & Applications:

• Large-Scale Irrigation & Agricultural Systems — The highest-volume commercial application for an 8" x 4" bushing; used at 8-inch manifold outlets, mainline tee branches, and header fitting sockets where the downstream run transitions to a 4-inch zone supply header, submain, or valve station — the two-size step-down reflecting the standard irrigation design convention of stepping pipe size down from the primary mainline to the zone distribution layer as cumulative flow demand decreases away from the pump station
• Municipal Water Distribution — Applied at 8-inch fitting outlets in municipal distribution mains where a 4-inch service lateral, zone supply, or secondary distribution main departs from the primary 8-inch infrastructure — the bushing accomplishing the reduction at the fitting socket rather than with a separate reducer coupling mid-run, keeping the junction assembly compact and the joint count minimal in systems where buried fitting count directly affects long-term leak risk
• Pump Discharge & Equipment Connections — Incorporated at pump discharge fitting outlets and equipment nozzle connections where an 8-inch fitting socket must supply a 4-inch downstream pipe run to a process header, distribution manifold, or equipment supply circuit — the 8" x 4" transition being one of the most common pump discharge size configurations in large commercial and industrial pumping systems across all market segments
• Industrial Process Piping & Manifolds — Specified in process plant distribution headers, manifold assemblies, and pipe rack layouts where an 8-inch fitting outlet must feed a 4-inch downstream process line or secondary distribution header — the bushing performing the reduction within the fitting socket rather than as a standalone reducer coupling in the open run, reducing assembly length and joint count in congested industrial piping layouts
• Commercial Plumbing & Mechanical Systems — Applied in large commercial building water mains and mechanical room distribution headers where an 8-inch primary supply fitting must transition to a 4-inch secondary supply circuit, equipment inlet, booster pump connection, or zone distribution main — the two-size step-down being the most standard pipe size reduction in commercial building piping from primary mains to zone supply headers
• Stormwater & Civil Site Utilities — Incorporated in civil utility plans for commercial developments and infrastructure projects where 8-inch underground drainage or stormwater fittings supply 4-inch downstream runs at designed reduction points — the 8" x 4" step-down being a practical and frequently occurring transition in branched stormwater collection networks where primary mains distribute flow to smaller lateral conveyance runs