8" Blind Flange, PVC Schedule 80 (853-080)

The 8" PVC Schedule 80 Blind Flange (853-080) is a solid, bolt-on flange plate engineered to terminate, isolate, or blank off an 8" flanged pipeline end — providing a pressure-rated, removable closure at pipe terminations, vessel nozzles, equipment connection points, and system boundary locations where a permanent solvent-weld cap is inadequate for the service requirements. Unlike a solvent-cemented cap that creates a permanent, non-removable termination, the blind flange bolts directly to a mating 8" flange face and can be removed, inspected, and reinstalled without cutting pipe, disturbing joints, or interrupting adjacent piping — making it the preferred termination method wherever future system extension, periodic inspection access, or equipment connection flexibility is anticipated over the life of the installation.

The Schedule 80 construction provides the increased wall thickness, higher pressure rating, and enhanced mechanical strength required in industrial, chemical processing, and heavy-duty process piping environments where a standard Schedule 40 blind flange does not meet the pressure class or structural demands of the service conditions. Manufactured from gray PVC compound meeting ASTM D2467 dimensional standards, the 853-080 delivers the broad chemical resistance to acids, caustics, solvents, and oxidizing fluids that makes Schedule 80 PVC the specified material across the most demanding corrosive service applications where metal flanges would require expensive alloy upgrades or corrosion-resistant coatings to achieve equivalent service life.

At 8" diameter, the blind flange is a physically substantial fitting subject to significant hydrostatic end force under pressure — the product of line pressure acting on the full 8" bore area produces a substantial net load on the flange bolting and gasket, making proper bolt pattern torque, gasket selection, and flange face alignment critical execution details at this size. The 853-080 is dimensioned to ANSI/ASME flange standards to ensure compatibility with standard 8" PVC flange adapters, stub ends, and mating metal flanges across the range of bolting patterns used in industrial piping systems.

Specifications:

A full-face gasket is required between the blind flange and the mating flange face to achieve a proper seal — do not assemble metal-to-PVC flange faces without a gasket. Tighten bolts in a cross pattern using graduated torque increments to avoid uneven flange face loading and PVC cracking. Do not apply metal pipe torque values to PVC flange bolting — overtightening is a primary cause of PVC flange cracking at the bolt hole locations. Stainless steel or non-corrosive bolting hardware is recommended in chemical or wet service environments. Pressure-temperature derating applies at elevated service temperatures per ASTM standards. Verify chemical compatibility of both the PVC body and the gasket material for non-water service prior to installation.

Industries & Applications:

• Chemical Processing & Transfer — Permanent or temporary termination of 8" Schedule 80 flanged chemical supply headers, manifold outlets, reactor nozzles, and storage vessel connections in corrosive acid, caustic, or oxidizing fluid service where bolt-on access for future system extension or equipment connection is required without cutting pipe or disturbing permanent joints
• Industrial Process Piping — Blanking off unused 8" flanged nozzle outlets on process vessels, heat exchangers, pump manifolds, and distribution headers during initial system commissioning, equipment phased installation, or process line decommissioning where future reactivation of the connection point is anticipated
• Water & Wastewater Treatment — Terminating 8" flanged pipeline ends at treatment plant process boundaries, filter manifold unused ports, aeration distribution system terminals, and chemical feed header dead ends where Schedule 80 pressure rating and chemical resistance are required and periodic access for system extension or inspection is operationally valuable
• Industrial Wastewater & Effluent Handling — Blanking flanged outlets on 8" Schedule 80 collection headers, neutralization tank nozzles, and effluent transfer system boundaries in aggressive industrial waste service where a pressure-rated, removable termination is preferred over a permanent cemented cap
• Semiconductor & Electronics Manufacturing — Terminating unused nozzle outlets and system boundary connections on 8" Schedule 80 UPW and chemical distribution systems where future process additions, tool connections, or system expansions require a removable, cleanroom-compatible flanged closure maintaining full Schedule 80 chemical resistance at the termination point
• Plating & Metal Finishing — Blanking unused tank nozzle connections, header outlets, and process line terminals in acid, caustic, and electroplating chemical systems where a corrosion-resistant, pressure-rated flanged closure provides both service termination and future access without exposing permanent piping joints to repeated disassembly stress
• Power Generation Facilities — Terminating unused nozzle connections on cooling water distribution headers, chemical treatment system manifolds, and demineralized water distribution boundaries where Schedule 80 construction is specified and future system expansion, equipment addition, or connection reactivation is a planned operational possibility
• Industrial Cooling & HVAC Systems — Blanking unused flanged outlets on 8" cooling water distribution headers, chemical treatment skid connections, and condenser water system boundaries where a removable flanged closure provides system termination with future access capability for equipment additions or circuit expansions