DeZURIK diaphragm actuators are designed specifically for use on quarter-turn valves. They feature all steel, cast iron and stainless steel construction for corrosion resistance in caustic environments. The actuators are designed for on-off or modulating service in either a fail-open or fail-closed mode. Action can be easily changed in the field with no additional parts required. The spring cartridge is caged at the factory for increased safety. The output shaft is supported at the top and bottom with bronze bearings that absorb side thrust and insure smooth, efficient, and accurate throttling control.