Flange (Loose Ring), Slip PVC Schedule 80 8" (854-080FT)

The 8" PVC Schedule 80 Loose Ring Flange (Slip) — also known as a van stone flange or lap joint flange — is a two-piece thermoplastic flanged connection assembly consisting of a solvent-weld stub end and a separate loose backing ring that rotates freely behind the stub end face. The slip socket on the stub end accepts 8-inch Schedule 80 PVC pipe via solvent cement, while the loose ring slides over the pipe before cementing and remains free to rotate after installation — allowing the bolt holes to be aligned with a mating flange without rotating the pipe or stub end itself.

This rotational freedom is the defining functional advantage of the loose ring flange over a solid style (one-piece) flange. In a solid flange, the bolt pattern is fixed at the moment the fitting is cemented to the pipe — if the holes do not align with the mating flange, there is no adjustment available without cutting out and replacing the fitting. The loose ring eliminates this constraint entirely. The ring can be spun to any rotational position after the stub end is cemented, allowing the installer to align the bolt circle with the mating flange face regardless of how the pipe was oriented during installation. At 8 inches — where flanged connections are heavy, the mating equipment is typically fixed in place, and field alignment adjustments are physically demanding — this flexibility has real practical value.

The two-piece van stone assembly also offers a maintenance advantage in systems that see periodic disassembly. When the flange is unbolted for pump service, valve replacement, or equipment access, the loose ring can be removed without disturbing the cemented stub end remaining on the pipe. The stub end stays in place; only the ring and gasket are handled during each service cycle. Over the service life of a large industrial system with multiple flanged connections, this translates to meaningfully faster maintenance cycles and reduced risk of damage to the pipe during repeated disassembly.

The stub end face is machined flat for use with a full-face gasket against ANSI 150 lb mating flanges across materials — PVC, ductile iron, stainless steel, or other flange-compatible materials. Schedule 80 PVC provides the elevated wall thickness and pressure rating required for the industrial environments where 8-inch flanged connections are most commonly specified. Manufactured to ASTM D2467 standards with the loose ring drilled to ANSI B16.5 150 lb bolt pattern for broad compatibility.

Specifications:

Industries & Applications:

• Pump Connections & Mechanical Equipment — The most common large-diameter application; the rotating ring allows bolt hole alignment with pump flanges, valve bodies, and equipment connections without requiring the pipe assembly to be rotated — critical when working with fixed, heavy equipment in constrained mechanical spaces
• Water & Wastewater Treatment — Used at filter housings, clarifier connections, chemical dosing equipment, and treatment plant process tie-ins where 8-inch flanged connections require both initial alignment flexibility and repeated access for periodic maintenance and equipment replacement
• Industrial Chemical Processing — Specified in chemical-resistant 8-inch PVC systems where flanged joints at equipment interfaces must accommodate field alignment variability and provide clean, repeatable disassembly for process equipment service in chemical handling, semiconductor, and industrial manufacturing environments
• Irrigation & Agricultural Infrastructure — Applied at pump discharge connections, large filter manifolds, and mainline isolation valve flanges on large commercial and agricultural irrigation systems where equipment serviceability and bolt alignment at large-diameter connections are design priorities
• Municipal Infrastructure & Pump Stations — Incorporated in pump station discharge headers, lift station piping, and treatment plant process mains where 8-inch flanged connections are standard practice for long-term operational flexibility and the rotating ring simplifies installation against fixed municipal equipment flanges
• HVAC & Industrial Mechanical Systems — Used in large chilled water loops, cooling tower mains, and process cooling systems where PVC is specified for corrosion resistance and 8-inch flanged connections at chillers, cooling towers, or heat exchangers require alignment flexibility during installation