SISTO-C Bonnets with piston actuator MD 168-202 Features ? Piston actuator ? Stainless steel actuator housing ? Stainless steel bonnet ? Stainless steel stem ? Clear visual position indication by red plastic indicator – well visible all around ? Stainless steel compressor ? Floating nut ? Spring chamber venting by operation hole ? Spring to close – air to open ? Stainless steel spiral spring support Variants ? Spring to open – air to Close ? Air to open – air to Close ? Aluminium hard anodised actuator housing ? High temperature design with FKM/FPM seal (Recommendation: >= 80 °C measured at actuator housing) Options ? Limit switches ? Positioner ? Adjustable travel stop