Bushing, Spigot x Slip (Flush Style) PVC Schedule 80 12" x 8" (837-668)

The 12" x 8" PVC Schedule 80 Bushing (Spigot x Slip, Flush Style), Part #837-668, is a heavy-wall, large-diameter reducing bushing engineered to adapt a 12-inch slip-socket fitting down to accept an 8-inch pipe or spigot connection. Manufactured from Type I, Grade I PVC compound to ASTM D2467 specifications, this fitting delivers Schedule 80's elevated pressure rating, increased wall thickness, and broad chemical resistance — making it the correct specification for industrial process, chemical handling, and high-demand municipal infrastructure where a Schedule 40 bushing would be underspecified or where engineering drawings mandate Schedule 80 throughout.

The spigot x slip connection defines how this bushing integrates into an existing system: the spigot (male, plain) end is dimensioned to insert directly into a 12-inch slip socket on an existing fitting, valve, or equipment port, bonded in place with solvent cement; the slip (female, socket) end then receives an 8-inch pipe or spigot fitting, also solvent welded. This in-socket configuration eliminates the need for a separate reducer coupling when a 12-inch slip socket is already present in the line — consolidating what would otherwise be a two-fitting assembly into a single, compact, purpose-built reducer.

The flush style body is a critical specification distinction at this size. Unlike hex (flanged) bushings, which protrude beyond the face of the mating socket and can impose mechanical stress or create clearance conflicts in tight assemblies, the flush bushing body sits fully recessed within the 12-inch socket. This low-profile design is particularly valuable at large diameters where hex bushing flanges become proportionally more obstructive, and where buried, vault, or manifold installations leave little tolerance for protruding fitting geometry.

At the 12" x 8" size differential, this bushing handles a significant flow transition in a single fitting — a reduction that would otherwise require a dedicated reducer coupling added to the line. For existing systems with an open 12-inch slip socket at a valve, tee, lateral connection, or equipment port that must now feed an 8-inch downstream circuit, Part #837-668 provides a direct, specification-compliant, single-piece solution without modifying the upstream fitting.

Specifications:

Note: Pressure ratings for large-diameter PVC fittings decrease relative to smaller sizes and are further reduced at operating temperatures above 73°F. Consult ASTM D2467 pressure derating curves and applicable engineering specifications before installation in high-pressure or elevated-temperature service. The 12" x 8" size differential introduces meaningful flow velocity changes at the transition — account for turbulence, minor pressure loss, and hydraulic thrust in system design. Proper large-diameter solvent weld technique, including surface preparation, primer, and adequate cure time, is essential at this pipe size.

Industries & Applications:

• Industrial Process Piping — In-socket diameter reduction at valves, tees, and equipment ports where an existing 12-inch slip socket must transition to an 8-inch process line or branch circuit without the addition of a separate reducer coupling upstream.
• Chemical Handling & Water Treatment — Reducer bushings for chemical distribution headers, treatment plant manifolds, and dosing system connections where PVC's resistance to acids, caustics, and chlorinated media is a primary material driver and Schedule 80 wall thickness is required by specification.
• Municipal Water Distribution — Large-diameter service transitions, branch connections, and appurtenance fittings on 12-inch transmission or distribution mains where an in-socket reduction to 8-inch is required at valves, tees, or meter assemblies.
• Industrial Valve Manifolds — Adapting large-bore valve bodies with 12-inch slip ports to 8-inch downstream piping circuits in systems where valve sizing is governed by mainline flow capacity rather than branch circuit requirements.
• Wastewater & Force Main Infrastructure — Pressurized discharge lines, pump station manifolds, and force main lateral connections where a 12-inch fitting socket must transition to an 8-inch branch or service run under Schedule 80 specification.
• Irrigation & Agricultural Systems — High-pressure mainline manifold transitions where 12-inch supply headers feed 8-inch zone or sector circuits at control valve assemblies, pump discharge headers, or filter stations operating above Schedule 40 pressure limits.
• HVAC & Mechanical Systems — Large commercial and industrial chilled water mains, condenser water loops, and cooling tower piping where 12-inch distribution headers must reduce to 8-inch equipment or branch feeds within tight mechanical room assemblies.
• Power Generation & Heavy Industrial — Cooling water, service water, and chemical injection system connections at large-diameter headers in refineries, power plants, and heavy process facilities where Schedule 80 is the baseline specification.
• Mining & Aggregate Processing — Process water mains and dewatering discharge systems requiring large-diameter corrosion-resistant in-socket reduction in aggressive or abrasive operating environments.