Flange (Loose Ring), Spigot PVC Schedule 80 2-1/2" (856-025)

The 2-1/2" PVC Schedule 80 Loose Ring Spigot Flange (856-025) provides a removable, bolted flanged connection in Schedule 80 PVC piping systems where the spigot end configuration is required to insert directly into a mating socket fitting, valve body, or equipment port rather than accepting pipe into a hub socket. Manufactured from rigid gray PVC conforming to ASTM D1784 Cell Class 12454, this fitting is engineered for the pressure ratings, chemical resistance, and service demands of industrial, municipal, and commercial Schedule 80 applications.

The loose ring (van stone) design separates the PVC flange hub from the backing ring, allowing the backing ring to rotate freely around the flange hub prior to bolt-up. This free rotation is a practical installation advantage—bolt holes in flanged systems rarely align perfectly on the first fit, and the ability to rotate the backing ring independently of the pipe and hub eliminates the need to rotate the entire pipe run to achieve alignment. On multi-flange assemblies, pump connections, and valve trains where several flanges must align simultaneously, this feature alone can meaningfully reduce installation labor.

What distinguishes the 856-series from the 854-series slip flange is the spigot (SPG) end. Rather than accepting pipe into a socket hub via solvent weld, the spigot end is sized to the outside diameter of 2-1/2" Schedule 80 pipe, allowing it to insert directly into any standard 2-1/2" PVC socket fitting—such as a tee, coupling, cross, or valve body—as the male solvent-weld member of that joint. This makes the 856-025 the correct flange choice when the flange must terminate into a socket-end fitting rather than receive pipe from an open end, a distinction that matters in prefabricated spool assemblies, compact valve trains, and equipment connections where the socket end of the adjacent fitting is the available connection point.

The 150 lb. ANSI/ASME B16.5 bolt pattern on the flange face ensures direct compatibility with standard flanged pumps, valves, strainers, tanks, and equipment throughout the system. Once bolted, the flanged joint creates a fully pressure-rated, gasket-sealed connection that can be unbolted and separated at any time for maintenance, equipment service, inspection, or component replacement—without cutting into the pipeline. Schedule 80 construction maintains consistent pressure class with surrounding Schedule 80 pipe and fittings. Gray PVC delivers broad chemical resistance to acids, bases, salts, and a wide range of industrial process fluids. For service above 140°F, consult CPVC Schedule 80 equivalents.

Specifications:

Industries & Applications:

• Chemical Processing — Flanged pump, valve, and equipment connections on chemical feed, dosing, and transfer lines where the spigot end inserts into a socket-end valve body or fitting in a compact spool assembly
• Water & Wastewater Treatment — Pump isolation flange joints, strainer connections, and treatment equipment interfaces on 2-1/2" Schedule 80 process piping at pump stations and treatment facilities
• Industrial Manufacturing — Prefabricated Schedule 80 spool assemblies and valve trains where spigot-end flanges are required to interface with socket-end fittings or equipment ports
• Irrigation & Agriculture — Flanged pump station connections and filter manifold interfaces on 2-1/2" Schedule 80 commercial irrigation and fertigation systems
• Municipal Infrastructure — Lift station, water distribution, and treatment plant piping where bolted flanged joints provide accessible, disconnectable connections on 2-1/2" Schedule 80 mains
• Aquaculture & Aquatics — Recirculating system pump and filtration equipment flanged connections where spigot-end flanges interface with socket fittings in compact mechanical assemblies
• HVAC & Plumbing — Commercial mechanical systems with Schedule 80 PVC piping requiring bolted flanged connections at equipment interfaces with spigot-to-socket joint geometry