All-plastic, yet highly resistant to corrosion. That’s the promise made by South Korean diaphragm valve supplier Fluonics of its series of fluoropolymer-lined products whose bodies are molded from various thermoplastic materials, including polyvinyl chloride (PVC), 30-percent glass-fiber-reinfored polypropylene (PP), 40-percent glass-fiber-reinforced polyphenylene sulfide (PPS) and 40-percent glass-fiber-reinforced polyphthalamide (PPA).
Speaking to Fluid & Gas Flow Journal at the recent Process Systems show in Singapore, Kevin Yi, Fluonics’ sales manager, said the company’s diaphragm valves “are being employed in a variety of industries where highly alkaline or acidic media are employed, such as the semiconductor, fine chemical, petrochemical and steel sectors.” Fluonics offers perfluoroalkoxy (PFA) and polyvinylidene fluoride (PVDF) as corrosion-resistant lining material options.
Fluonics is targeting substitution of expensive PVDF valves supplied by companies such as Georg Fischer, from Ingelfingen, Germany, and Asahi Organic Chemical Industries, in Tokyo, that can operate at temperatures up to 70 deg C, as well as PVC valves whose maximum operating temperature is 60 deg C. “We see many users employing low-cost PVC valves in corrosive environments and opting to replace them frequently,” says Yi.
The company’s PPS-bodied diaphragm valves can be used at continuous-usage temperatures up to 200 deg C, compared with 185 deg C for the PPA-bodied valve. “We’re still looking for an application for the PPA version, given it costs around the same as the PPS option but has a lower continuous-usage temperature,” Yi concedes, before adding, “but we may uncover areas where corrosive vapors may affect the use of PPS.”
The PVC-bodied valve employs a bonnet molded from PPS in order to improve durability, according to Yi. This is an example of the company’s mix-and-match strategy to optimize valve performance. “Wrench bolts and the spindle can be either stainless steel or titanium,” Yi adds.
Fluonic claims to be the world’s sole supplier of fluoropolymer-lined plastic diaphragm valves. The valves were commercialized this year.