1-1/4" Flange (Solid Style), Slip PVC Schedule 80 (851-012)

The 851-012 is a Schedule 80 PVC solid style flange in 1-1/4" with a slip (socket) end connection. Unlike the loose ring (Van Stone) flange design, the 851-012 is a one-piece fixed construction — the flange face and socket hub are molded as a single unit, with no separate backing ring. This solid construction produces a more rigid, structurally robust flanged termination point, making it the preferred choice in installations where the flange will remain in a fixed position and bolt hole alignment can be established during initial pipe layout.

The slip socket end accepts 1-1/4" Schedule 80 PVC pipe directly for solvent cement installation. Once cemented, the flange face presents a flat-faced ANSI Class 150 bolt pattern for connection to mating flanges on pumps, valves, tanks, strainers, and other flanged equipment. The one-piece body eliminates the potential for the stub-to-ring interface movement present in loose ring designs, making the solid flange the right call in high-vibration environments or where a completely rigid connection is specified.

Manufactured from gray Schedule 80 PVC, the 851-012 offers thicker walls and higher pressure ratings than Schedule 40 flanges, with excellent resistance to corrosion, acids, bases, and a broad range of industrial chemicals. Flat-faced flange geometry conforms to ANSI/ASME B16.5 Class 150 bolt circle dimensions, ensuring compatibility with standard metallic and plastic mating flanges.

Use PVC primer and a solvent cement rated for Schedule 80 fittings on the slip socket joint. Install a full-face gasket — typically EPDM or PTFE sheet — between mating flange faces, and torque flange bolts evenly in a cross pattern to avoid uneven stress on the flange face.

Specifications:

Industries & Applications:

• Industrial Process Piping — Fixed flanged terminations on Schedule 80 PVC pipe runs connecting to pumps, control valves, strainers, and instrumentation in chemical processing, manufacturing, and water treatment facilities
• Chemical Handling — Permanent flanged connections in acid, caustic, or solvent transfer systems where a rigid, one-piece flange body is preferred for structural integrity and resistance to joint movement
• Water & Wastewater Treatment — Pump suction and discharge flanged connections, filter vessel inlets and outlets, and metering equipment tie-ins where fixed flange alignment is established during initial installation
• Pool & Spa / Aquatics — Flanged connections to commercial pump and filter equipment on Schedule 80 PVC equipment pad piping, particularly where vibration resistance or a fully rigid joint is preferred over a loose ring design
• Agricultural & Irrigation — Flanged tie-ins to pumping stations, filter banks, and pressure regulation equipment in large-scale agricultural water management and irrigation infrastructure
• OEM & Equipment Fabrication — Fixed flanged termination points on PVC process skids, chemical dosing systems, and custom equipment assemblies where bolt hole orientation is determined at design time