Retrofitting Material Systems with Butterfly Valves at a Chlor-Alkali Enterprise

A large-scale chlor-alkali chemical enterprise had long relied on globe valves, gate valves, and diaphragm valves for its process control systems handling materials such as industrial water, brine, electrolyte, caustic solution, and chlorine gas. As production capacity expanded, the shortcomings of the existing valves became increasingly apparent: the valve plugs of globe valves and gate valves were prone to detachment, and severe wear at the stem packing—caused by frequent operation—led to material leakage and environmental pollution; meanwhile, the diaphragms of diaphragm valves frequently ruptured, and their exposed actuation mechanisms were susceptible to operational difficulties caused by rust and dust accumulation. Addressing the specific characteristics of each material system, the plant’s technical team gradually replaced the original valves with butterfly valves featuring various sealing pair configurations manufactured by our company. In the circulating water system, the original gate valves (DN300 and DN400 sizes) required two or three people to operate; after switching to our butterfly valves—featuring a nitrile rubber and ductile iron sealing pair—a single operator could handle them with ease. In systems handling highly corrosive brine and electrolyte, our butterfly valves reduced the number of static sealing points by two compared to the original valves, significantly lowering the risk of leakage; furthermore, the actuation mechanism was fully enclosed within the valve body, preventing damage from corrosive gases. Following this upgrade, the enterprise not only enhanced its process control capabilities and reduced material waste and environmental pollution but also significantly lowered the maintenance workload for operators, extending the plant-wide valve maintenance interval from once a month to once a quarter.