1-1/2" Flange (Loose Ring), Spigot PVC Schedule 80 (856-015)

The 856-015 is a 1-1/2-inch Schedule 80 PVC loose ring flange — also known as a Van Stone flange or lap joint flange — with a spigot pipe connection on the stub end body. Unlike a solid (one-piece) flange where the flange face and pipe connection are permanently fixed in a single integral fitting, the loose ring flange is a two-piece assembly: a PVC stub end with a flat flange face and a spigot pipe connection, and a separate flange ring that slides over the pipe end of the stub end and rotates freely around it. The rotating ring carries the bolt holes and bolts up against the mating flange face, while the stub end provides the sealing face and the pipe connection — the two components work together but are not fixed to one another.

The rotational freedom of the loose ring is the primary operational advantage this design holds over a solid flange. Because the ring is not bonded or mechanically fixed to the stub end, it can be rotated freely at any point before the bolts are tightened — including after the stub end has been solvent welded into the piping system and the cement has fully cured. This means bolt hole alignment with the mating flange can be achieved by rotating the ring rather than by rotating the entire pipe assembly, eliminating the precise rotational positioning requirement that solid flanges impose at the time of solvent weld installation. On systems where exact bolt hole alignment is difficult to achieve during installation — tight spaces, pre-fabricated assemblies, field installations where pipe orientation is constrained — the loose ring design provides meaningful practical flexibility that a solid flange cannot.

The spigot pipe connection on the 856-015 stub end is a plain male end dimensioned to the same OD as Schedule 80 PVC pipe, designed to insert into the female socket of a mating fitting or coupling for solvent weld assembly. A spigot end inserts into a socket — this is the reverse of a slip socket fitting which receives pipe. The spigot connection is used when the flange must be installed at a fitting-to-fitting joint rather than directly onto a cut pipe end, and is an important distinction from slip socket flange designs when planning the pipe assembly.

The loose ring is drilled to the ANSI/ASME B16.5 Class 150 pattern — the industry-standard 4-bolt configuration at 1-1/2-inch nominal size — ensuring compatibility with standard mating flanges across manufacturers and materials. The stub end face is flat and smooth, designed to seat against a full-face gasket when assembled. Gray Schedule 80 PVC construction provides the pressure rating and chemical resistance required for industrial chemical process, water treatment, and utility service. The stub end is manufactured from virgin PVC compound conforming to ASTM D1784 Cell Classification 12454 and dimensioned to ASTM D2467 standards for Schedule 80 PVC fittings.

Specifications:

Pressure rating reflects Schedule 80 PVC stub end at 73°F water service. Assembled flange joint ratings depend on gasket material and compression, bolt torque, mating flange material, and fluid service conditions. Always use a full-face gasket with PVC flanges. Consult system design specifications for pressure and temperature derating. Do not overtighten flange bolts — follow manufacturer torque specifications for PVC flange assemblies to avoid cracking the stub end face.

Industries & Applications:

The 856-015 loose ring flange is specified across industrial, chemical, and process piping wherever flanged 1-1/2-inch Schedule 80 PVC connections require post-installation bolt hole alignment flexibility or frequent disassembly for maintenance and equipment access:

• Chemical Processing & Water Treatment — Flanged connections on chemical dosing pumps, metering equipment, filter vessels, and instrumentation at points where bolt hole alignment flexibility during installation is essential and where the ability to rotate the flange ring post-installation simplifies assembly on pre-fabricated chemical skids and panel-mounted piping systems
• Pump Connections & Equipment Flanges — Van Stone flanges are a standard choice at pump inlet and outlet connections where pump alignment requirements, skid geometry, or field installation conditions make the rigid bolt hole positioning of a solid flange impractical; the loose ring accommodates minor angular adjustments without reorienting the pipe assembly
• Industrial Process Piping — Flanged isolation and connection points on 1-1/2-inch Schedule 80 chemical feed, reagent distribution, and process loop piping where flanged joints must be broken and remade periodically for equipment maintenance, inspection, or system modification — the loose ring design allows the ring to be slid back along the pipe for joint access without disturbing the stub end installation
• Municipal Water & Wastewater Treatment — Pump skid connections, valve isolation flanges, and equipment nozzle interfaces on treatment plant piping where ANSI 150 lb PVC flanges are specified and bolt hole alignment flexibility reduces installation time and rework on complex multi-flange assemblies
• Semiconductor & Electronics Manufacturing — Ultra-pure water and chemical delivery system flanged connections where PVC chemical resistance, cleanable flat-face gasket surfaces, and the non-reactive stub end face are required alongside the installation flexibility of a rotating ring design
• Agricultural & Irrigation Systems — Flanged pump and filter connections on pressurized 1-1/2-inch irrigation systems where the Van Stone design simplifies field assembly and allows bolt hole alignment to be achieved after the stub end is installed in often-constrained pump house or equipment enclosure environments
• Laboratories & Research Facilities — Flanged connections on reagent and process fluid systems where periodic equipment removal for cleaning, recalibration, or replacement is routine and the loose ring design allows the flange joint to be broken and remade without affecting the pipe installation