12" Slip Flange (Loose Ring), PVC Schedule 80 (854-120FT)

The 12" PVC Schedule 80 Slip Loose Ring Flange (854-120FT) is a heavy-duty, two-piece Van Stone-style flanged connection fitting built for large-diameter industrial and municipal piping systems that demand bolted, serviceable joints in chemically aggressive or high-purity environments. The assembly pairs a slip (socket) stub end — solvent welded permanently onto the pipe — with a free-rotating PVC backing ring that spins independently until the bolts are drawn down, allowing full 360° bolt hole alignment without repositioning or twisting the pipeline.

For 12" piping, this rotational freedom is a practical necessity. Large-diameter pipe is heavy and difficult to maneuver in confined mechanical rooms, vaults, or pump stations. The loose ring design eliminates the need to pre-orient the pipe run to match a fixed mating flange — the backing ring simply rotates to align with pump flanges, valve bodies, or equipment connections at final assembly, then locks in place under bolt tension.

The all-PVC construction keeps every wetted surface free of metal, preventing galvanic corrosion, metal ion contamination, and the dezincification or rust concerns associated with metal flanges in chemically treated or high-purity water systems. Schedule 80 wall thickness provides the structural depth and pressure margins required beyond Schedule 40 limits, and the flat face flange face mates correctly with full-face gaskets to protect the flange sealing surface under bolt load.

Drilled to the 150 lb. ANSI/ASME B16.5 pattern, the 854-120FT is dimensionally compatible with standard metal and PVC companion flanges, pump discharge flanges, butterfly valve wafer ends, and inline equipment across municipal, industrial, and chemical process applications.

Specifications:

Industries & Applications:

Chemical Processing & Industrial Fluid Handling Large-diameter chemical transfer headers carrying acids, caustics, chlorinated solutions, and industrial solvents require flanged break points for pump isolation, equipment removal, and system maintenance. The all-PVC wetted path of the 854-120FT resists the corrosive media that degrade metal flanges, and the free-rotating backing ring eliminates the alignment difficulty that comes with heavy, rigid 12" chemical pipe runs.

Municipal Water & Wastewater Treatment Pump station headers, filter influent and effluent piping, clarifier connections, and chemical dosing system mains in water and wastewater treatment plants are routinely built with flanged PVC at isolation and equipment interfaces. The ANSI 150 drilling pattern ensures direct compatibility with pump flanges, gate valves, and butterfly valves standard to municipal infrastructure.

Industrial Cooling & Process Water Systems Cooling tower distribution mains, chiller plant headers, and closed-loop recirculating systems use Schedule 80 PVC flanges where chemical treatment of the water supply makes metallic piping unsuitable. Flanged joints at heat exchangers, strainers, and balancing valves allow seasonal maintenance and equipment replacement without cutting the main.

Power Generation & High-Purity Utility Piping Demineralized water systems, condensate polishing loops, and service water headers in power generation facilities require piping materials that will not contribute metal ions to ultra-pure process streams. Schedule 80 PVC flanges at 12" serve primary distribution headers where mechanical strength and chemical inertness must coexist.

Mining & Mineral Processing Process water headers, leachate collection mains, and reagent distribution piping in mining and mineral processing operations are exposed to highly acidic or alkaline solutions that rapidly degrade carbon steel or ductile iron. The 854-120FT provides a fully corrosion-resistant flanged connection for large-diameter lines in these environments, with the loose ring simplifying maintenance at remote pump stations and treatment facilities.

Large-Scale Agricultural & Industrial Irrigation Pump station discharge flanges, filter station inlet and outlet connections, and mainline isolation points in large irrigation infrastructure use 12" flanged PVC to mate directly with pump and valve equipment. The rotating backing ring is particularly practical at pump discharge connections where bolt circle orientation must match the fixed pump flange without repositioning the pipe header.