Flange (Solid Style), Slip PVC Schedule 80 2-1/2" (851-025)

The 2-1/2" PVC Schedule 80 Solid Style Slip Flange (851-025) provides a permanent, one-piece flanged termination in Schedule 80 PVC piping systems where a rigid, integral flange body is preferred over a loose ring (van stone) assembly for maximum structural integrity at the flanged joint. Manufactured from rigid gray PVC conforming to ASTM D1784 Cell Class 12454, this flange is engineered for the pressure ratings, chemical resistance, and mechanical demands of industrial, municipal, and commercial Schedule 80 pressure piping.

The defining characteristic of the solid style flange is its one-piece molded construction—the flange hub, flange face, and bolt hole pattern are formed as a single integral body rather than as a separable hub-and-backing-ring assembly. This eliminates the rotatable backing ring of the loose ring design in favor of a fixed, rigid flange face that is permanently bonded to the pipe via the slip (socket) end. The result is a flanged joint with no secondary components, no possibility of the backing ring disengaging or misaligning under system stress, and a direct, continuous load path from the pipe through the flange face to the bolted joint.

The slip (socket) end accepts standard 2-1/2" Schedule 40 or Schedule 80 PVC pipe via solvent cement, creating a permanent, pressure-rated connection at the pipe-to-flange interface. Once solvent-welded and bolted to its mating flange, the assembly delivers a fully rated flanged joint suitable for the system's working pressure and chemical service conditions. The 150 lb. ANSI/ASME B16.5 bolt pattern ensures direct compatibility with the full range of standard flanged valves, pumps, strainers, tanks, and equipment.

The primary installation consideration with a solid style flange versus a loose ring flange is bolt-hole alignment. Because the flange face is fixed relative to the pipe and cannot rotate independently, the pipe must be positioned so that the bolt holes align with the mating flange before the solvent-weld joint sets. In systems where precise rotational alignment can be established during fabrication—such as prefabricated spool assemblies, shop-built skids, and valve trains assembled before installation—this is straightforward and the solid style flange delivers a cleaner, simpler flanged connection without a separate backing ring component to manage.

At 2-1/2", this flange is well-suited for pump connections, valve isolation joints, equipment interfaces, and process piping flanged terminations across a broad range of industrial and commercial applications. Schedule 80 construction maintains consistent pressure class with surrounding Schedule 80 pipe and fittings throughout the system. Gray PVC delivers broad resistance to acids, bases, salts, and a wide range of industrial process fluids. For service temperatures above 140°F, consult CPVC Schedule 80 equivalents.

Specifications:

Industries & Applications:

• Chemical Processing — One-piece flanged connections on chemical feed, dosing, and transfer line pump and valve interfaces where a fixed, integral flange body is preferred for structural rigidity and simplicity in prefabricated spool assemblies
• Water & Wastewater Treatment — Pump isolation flanges, strainer connections, and treatment equipment interfaces on 2-1/2" Schedule 80 process piping at pump stations and treatment facilities
• Industrial Manufacturing — Shop-fabricated Schedule 80 spool assemblies and valve trains where solid style flanges are assembled with known bolt-hole alignment before field installation
• Irrigation & Agriculture — Pump station flanged connections and filter manifold interfaces on 2-1/2" Schedule 80 commercial irrigation and fertigation systems where prefabricated assemblies are standard practice
• Municipal Infrastructure — Lift station, water distribution, and treatment plant piping where solid style flanges provide rigid, low-component-count flanged connections on 2-1/2" Schedule 80 mains
• Aquaculture & Aquatics — Recirculating system pump and filtration equipment flanged connections where one-piece flange construction simplifies assembly on shop-built system modules
• HVAC & Plumbing — Commercial mechanical systems with Schedule 80 PVC piping requiring bolted flanged connections at equipment interfaces where rotational alignment can be set during fabrication