An improved bonnet assembly for a weir type or radial style valve, comprising a hollow bonnet housing an actuator assembly comprising an actuator connected to a spindle, the hollow bonnet having a plurality of orifices to allow free entry and exit of a liquid such as a cleaning solution within the bonnet and to enable the liquid to thoroughly contact and exit the bonnet assembly without the need of disassembly. The valve or parts of the valve such as the bonnet assembly or its components are made of performance engineered polymeric material to prevent corrosion and/or galling, and also reduce the weight and sometimes the cost of the valve without sacrificing quality and performance.