[iamstupid]

i am thinking about crusher control and screening control, i have try very hard to search books  and internet, but i cannot find any information about controllers or valves of crushing process, as i know process control is more to safety section. i would like to know how the plant control crusher and also the safety in crushing process, also is there any P and ID for crushing in a manufacture plant ? (so far i got a lot of P and id of distillation)

thank you for helping me
i appreciate it !