Ptfe Teflon Lined Flanged Gate Valve

A lined gate valve serves as a bi-directional shutoff unit designed to isolate aggressive industrial chemicals without corrosive fluid contacting structural metals. Pure fluorocarbon linings encapsulate ductile iron or carbon steel bodies, providing bubble-tight sealing against nitric acid, hydrofluoric acid, and hot alkaline solutions while direct conduit geometry prevents particulate build-up.

Flexible Wedge Mechanics and Thermal Creep Compensation

Installing a ptfe lined gate valve across severe process piping eliminates seating failure caused through thermal cycles. Precision-machined floating wedge discs self-adjust against tapered body seats, countering fluoropolymer cold flow through controlled mechanical resilience.

Parallel guiding ribs cast inside the body channel the wedge along its travel path, preventing angular deflection and localized lining friction under maximum pipeline differential pressure.

Fluoropolymer Chemical Resistance and Temperature Limits

Outside Screw and Yoke Architecture for External Stem Protection

Employing a teflon lined gate valve with an outside screw and yoke configuration keeps operating threads outside the fluid flow path. Isolating the stem threading from internal chemical media prevents thread seizure, corrosive degradation, and atmospheric crystallization.

External rising stems offer instant visual verification regarding open or closed line position. Live-loaded Belleville spring washers exert steady downward thrust upon chevron packing sets, stopping fugitive emissions without requiring frequent packing adjustments.

Dove-Tail Mechanical Retention and Spark Verification

Machined dovetail grooves anchor the fluoropolymer liner mechanically inside the metallic housing, preventing liner collapse during sudden vacuum shocks, pipeline drainage, or flash evaporation. Flange faces feature integrated molded sealing ridges, forming leak-tight gaskets during installation between ASME B16.5 pipe flanges.

Non-destructive dielectric spark testing at 14 kV verifies seamless barrier continuity without microscopic pinholes. Hydrostatic pressure tests comply with API 598 protocols, confirming shell containment and seat integrity.

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Technical Specification