This table show the Processes and Instrumentation Diagrams that used special shapes to represent different types of equipment, valves, instruments and pipelines. Rotary compressor :- is a type of gas compressor which uses a rotary type positive displacement mechanism. Mixing :- is a device that combine or put some materials together to form one substance or mass. Mixing vessel :- is a container that is used to blend several components together. Heat exchanger :- is a device used to transfer heat energy between two process flows. Heat exchangers transfer heat energy through conductive and convective heat transfer. Cooling towers :- transfer heat energy to the outside air through the principle of evaporation. Cooler :- is a device, container or room that cools air through the evaporation of water or keeps air cool. Turbine driver :- is used to drive pumps and fans at petrochemical plants. Furnace :- is a device for heating a continuous current of air by means of a fire contained within the apparatus and without mingling the fresh air with the products of combustion. Boiler :- is a closed vessel in which water or other fluid is heated.