Reducer Bushing, Spigot x Slip 10" x 6" (C637-626)

The 10" x 6" PVC Class 125 Reducer Bushing (Spigot x Slip) is a large-diameter thermoplastic inline reducer engineered to transition from a 10-inch fitting connection point to a 6-inch downstream pipe run within a single compact fitting body. The 10-inch spigot end is a plain male outer-diameter that inserts directly into any standard 10-inch Class 125 slip socket fitting, while the 6-inch slip socket on the outlet end accepts 6-inch Class 125 PVC pipe for permanent solvent cement installation. The result is a four-size step-down — from 10 inches to 6 inches — accomplished entirely within the socket of an existing fitting, without a separate reducer coupling, additional fittings, or extra pipe sections occupying space or adding joint count to the assembly.

Compared to the previously described C637-628 (10" x 8"), the 10" x 6" configuration represents a more pronounced size differential — a step-down that carries more significant hydraulic implications at the reduction point. The transition from a 10-inch pipe to a 6-inch pipe reduces the cross-sectional flow area by more than half, which means flow velocity increases substantially through and downstream of the bushing. In gravity drainage systems, this velocity increase is generally managed by the downstream pipe slope and system design; in low-pressure or pumped systems, it must be accounted for in the hydraulic calculations governing pump selection, pressure loss, and downstream fitting sizing. Specifying the correct reduction point location and understanding the velocity profile change is part of the engineering basis for selecting this bushing over a more gradual two-stage reduction through an intermediate size.

The spigot-end configuration delivers the same assembly efficiency advantage established across the 437-series and C637-series bushing descriptions: the reduction occurs at the socket of an existing 10-inch fitting — a tee branch outlet, a coupling end, an elbow socket, or any other 10-inch Class 125 slip socket in the assembly — rather than in open pipe between two additional cemented joints. In buried drainage systems where excavation access is constrained and minimizing fitting count reduces both installation time and long-term leak point exposure, this geometry has practical engineering value that a standalone reducer coupling cannot replicate.

Class 125 PVC fittings are dimensioned to the cast iron pipe fitting pattern, making this bushing the correct specification for large-diameter drainage and gravity-flow systems where cast iron fitting geometry governs, or where PVC is being installed as a corrosion-resistant alternative to aging cast iron infrastructure. At both the 10-inch spigot end and the 6-inch slip socket, this bushing is dimensioned to Class 125 / cast iron pattern standards, ensuring full compatibility with mating Class 125 components in both sizes. Manufactured to ASTM D2466 standards.

Specifications:

Industries & Applications:

• Municipal Drainage & Stormwater — Used at 10-inch fitting outlets in underground stormwater collection networks where the downstream run steps down to 6 inches — a common reduction point in branched drainage systems where a primary 10-inch lateral transitions to a 6-inch secondary conveyance run serving a lower-load drainage area or downstream structure
• Large Commercial Building Drainage — Specified in below-grade gravity drain mains for large commercial, institutional, and industrial buildings where a 10-inch primary drain fitting — a tee branch, a coupling end, or an elbow outlet — must transition to a 6-inch lateral or branch run serving a lower-load area of the drainage network
• Civil & Site Utilities — Incorporated in site utility plans for commercial developments, campus infrastructure, and public works projects where 10-inch underground drainage or stormwater fittings supply 6-inch downstream runs at designed reduction points in the collection network — using the bushing to minimize fitting count and assembly length in buried utility corridors where excavation access is constrained
• Cast Iron System Replacement & Retrofit — Applied in cast iron drainage system upgrades where a 10-inch cast iron fitting outlet must transition to a 6-inch PVC downstream run; the Class 125 spigot end matches cast iron pattern socket dimensions, allowing the bushing to seat in an existing cast iron fitting socket during a phased retrofit without custom transition fittings or dimensional adaptation at the reduction point
• Industrial Discharge & Process Drainage — Used in large-bore industrial drain systems where a 10-inch collection header fitting must supply a 6-inch conveyance run to a lower-load downstream discharge point, secondary collection main, or treatment connection — accomplishing the reduction compactly within the existing fitting socket rather than as a separate reducer mid-run
• Water & Wastewater Treatment Facilities — Incorporated in gravity drainage and effluent conveyance lines within treatment plant infrastructure where 10-inch fitting outlets must transition to 6-inch downstream pipe runs between process areas, treatment stages, or collection points — maintaining the Class 125 / cast iron pattern dimensional standard throughout the reduction for full compatibility with mating components in both sizes