Fluorine-Lined Valve Package for an East China Chlor-Alkali Plant
Project Overview
The project supplied a complete package of lined butterfly valves, lined ball valves and corrosion-resistant globe valves to an integrated chlor-alkali plant in East China, for shutoff and control on brine, hydrochloric acid, sodium hypochlorite and other highly corrosive lines.
Challenge
The media are highly corrosive hydrochloric acid, sodium hypochlorite and wet chlorine gas. The plant runs continuously and does not allow frequent shutdowns. Conventional metal bodies showed pitting and seal failure within months. The owner required fully fluorine-lined metal bodies (PTFE/PFA), zero-leakage sealing, compliance with the relevant chemical standards and hydrostatic test records for every valve.
Our Solution
Selection was graded by medium concentration and temperature: brine and caustic lines use lined butterfly valves (wafer/flanged), hydrochloric acid and sodium hypochlorite lines use fully lined floating ball valves (PTFE seats), and instrument control branches use lined globe valves. Lining thickness in wetted parts is at least 3 mm, flange faces are fitted with anti-corrosion gaskets, and material certificates and individual pressure test reports are supplied with each delivery.
Results
After commissioning, the valves ran continuously for 18 months with no lining blistering or permeation and zero leakage at sealing points. Maintenance points that previously required quarterly shutdown replacement no longer needed replacement, and annual maintenance costs dropped noticeably. The client listed Vexval as a year-round supplier of spares for corrosive service.