12" Flange (Loose Ring), PVC Schedule 80 (856-120FT)

The 12" PVC Schedule 80 Loose Ring Flange (856-120FT) is a heavy-duty, two-piece Van Stone-style flange assembly designed for large-diameter piping systems that require bolted, removable connections in corrosive, high-purity, or chemically aggressive environments. Unlike a fixed-flange fitting where the bolt circle is permanently oriented, the loose ring flange separates the stub end — which solvent welds permanently to the pipe — from a free-rotating backing ring, allowing the bolt holes to be aligned to any mating flange without twisting or repositioning the pipeline.

This design makes the 856-120FT especially valuable in 12" installations where large-diameter pipe is heavy, space is constrained, and rotating an assembled run to align bolt holes is impractical. Once the stub end is welded in place, the backing ring rotates freely until bolted down, saving significant labor on initial installation and every subsequent reassembly.

Schedule 80 construction provides the greater wall thickness and structural integrity required in industrial and municipal applications where pressures, mechanical loads, and chemical exposure exceed Schedule 40 limits. The all-PVC wetted surface eliminates galvanic corrosion and metal ion contamination, making this fitting the correct choice wherever fluid purity, chemical resistance, or dissimilar-metal corrosion are concerns.

At 12", this is a commercial and industrial-grade component. Its applications span municipal water infrastructure, large chemical processing headers, industrial cooling systems, and wastewater treatment plant piping — anywhere a large-diameter bolted connection must be serviceable, chemically resistant, and dimensionally compatible with standard 150 lb. ANSI drilling patterns.

Specifications:

Industries & Applications:

Chemical Processing & Industrial Fluid Handling Large-diameter chemical transfer headers in processing plants require flanged connections that can be broken and reassembled for maintenance, cleaning, and equipment changes. The all-PVC wetted path of the loose ring flange resists the acids, caustics, and solvents that would corrode metal flanges, while the rotating ring eliminates the alignment difficulties inherent to large, heavy pipe runs.

Municipal Water & Wastewater Treatment 12" flanged connections are standard junction points in treatment plant piping — connecting pumps, valves, filters, clarifiers, and inline instrumentation. The loose ring design simplifies installation against fixed pump flanges and valve bodies where bolt circle alignment is critical and the pipe cannot be rotated.

Industrial Cooling & Chilled Water Systems Large recirculating cooling systems, chiller plant headers, and cooling tower distribution piping use flanged PVC in sections where chemical treatment of the water supply rules out metal piping. The serviceable bolted joint allows isolation valves, strainers, and heat exchangers to be removed for seasonal maintenance without cutting pipe.

Power Generation & Utility Infrastructure Demineralized water systems, condensate return lines, and cooling water intake piping in power facilities use Schedule 80 PVC flanges where ultra-pure water or chemically treated water must be conveyed without metal ion leaching. The 12" size is appropriate for primary distribution mains feeding multiple process loops.

Agricultural & Large-Scale Irrigation Infrastructure Pump station discharge headers and main distribution manifolds in large agricultural irrigation systems use flanged connections at pump outlets and filter stations. The loose ring design is especially practical at pump flanges where bolt hole alignment to a fixed pump discharge flange would otherwise require precise pipe positioning.

Mining & Mineral Processing Slurry transport, leach field distribution, and process water headers in mining operations are frequently built in Schedule 80 PVC to resist the highly acidic or alkaline solutions involved. Flanged connections allow sections to be isolated and replaced as wear or chemical attack dictates, with the loose ring simplifying maintenance in remote or constrained installations.