I am modelling the production of phthalic annhydride and my process has a lot of FIC, LIC, PIC notations in circles on the connections. Moreover there are what i think are temprature and pressure notations in a square and a triangle. But most primarily what does a pneumatic valve do?
pneumatic valve is nothing but a valve which is operated with the help of high pressure compressed air. the can be thought of as an alternative of a metal spring... These could retract valves more quickly and reduce the possibility of piston-valve interference as long as pressure could be maintained. Additionally, the amount of seat tension required to keep a coil sprung valve under control results in greater peak lift loading, with added stress to the entire valvetrain as a result.
pneumatic valves use pressurized gas (Air, nitrogen) to operate.A simple example if you are monitoring the level of a vessel in a process the indicator for level (LI) tells you remotely what the level is. If you need to keep the level stable the level indicating controller (LIC) sends a signal to the regulator on the Pneumatic Valve which provides air to open or close the valve depending on what the vessel level set point is. the FIC (flow indicating controller) PIC (pressure) TIC (tempurature) are all instrumentation used to compare a set point parameter against a measured process variable and send a signal to control the valve to maintain the set point
