Ceodeux S.A. Puretec (www.ceodeux.com) has introduced new standard flow cylinder valves for use with ultra-high purity and corrosive gases. Available worldwide, the company's D304 diaphragm valves incorporate double-seal seating technology.

The double-seal of the D304 valves combines a soft seat with a mechanical stainless-steel stop that prevents over-torquing of the valve. The standard soft seat is made of polychlorotrifluoroethylene (PCTFE), but the company offers soft seats made of a polyimide material or a polyvinylidene fluoride (PVDF) material as options.

The company said the double-seat combination reduces the gas permeation rate and extrusion of the soft seat disc and, by doing so, increases the serviceable life of each valve. The D304 also is designed to allow for metal-to-metal sealing in the event that a burn out of the soft seat should occur.

Each valve is manufactured and tested to CGA V-9 and ISO 10297 standards, and is available with pressure relief devices in accordance with CGA S-1.1.