The ZSH(DR)O series soft-seated ball valve uses a two-piece construction in small sizes and a three-piece construction in larger sizes. The body consists of main and auxiliary sections, while the full-bore ball provides a high rated flow coefficient and low flow resistance. The ball surface is specially hardened for smoothness and wear resistance; the seat uses carbon-fiber-reinforced PTFE for low wear, reliable sealing, long service life and strong shutoff performance. High-performance double-piston rack-and-pinion or scotch-yoke pneumatic actuators, or electric actuators, are available. Proper seat preload and travel limitation reduce operating torque, while a spring beneath the seat helps maintain stable torque. A blowout-proof bottom-entry stem improves safety. The fire-safe seat combines a stainless-steel seat with a PTFE sealing ring; if the PTFE is destroyed by fire, line pressure and the seat spring press the floating ball and stainless-steel seat together to establish a secondary metal seal. An antistatic device electrically bonds ball, stem and body to dissipate static electricity generated by operation.