Industrial Process Automation-Control Systems Engineering

SIL Notes Objective : SIL assignment establishes the risk reduction needed for each                     process system to protect against one or more hazards,                      The risk reduction is calculated as the gap between the existing risk posed by the                          process or  equipment and the risk target.                     Risk reduction (Layer of Protection) is provided by process and mechanical                                  integrity, Independent Protection Layers (IPLs) and required Safety Instrumented                      Systems (SIS). Scope :  The SIL level of each...

HAZOP notes *1 >>> The HAZOP study is primarily an audit review or problem              identification analysis based on Process P&ID-CE,F&G CE *2>>>  Problems associated with any design,were identified in a highly systematic manner studies *3>>> The objectives of  project basis HAZOP study were to identify process or operability related hazards such as potential for over pressure/under pressure and the toxicity/ flammable properties of process gas, fluid and to identify specific safeguards which are used to  control or eliminate the hazards *4>>> The operability hazards considered were generally operational upsets leading to serious consequences.Systems such as emergency isolation valves, gas detection,drainage, fire proofing, pressure relief and emergency depressurization systems were evaluated on the basis of their effect  on the process and operability hazards. Large portions...

Suggested Initial PID Tuning Parameters                  Service                                   P / Proportional   I / Integral              D / Derivative                                                                 K                        ...

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We use 4-20 mA signal for intrinsic safety purposes, as 4-20 mA signal is weak, it never cause fire / spark in-case of short circuit or Puncture. why we use current signal?,most of us know, the simple reason is to prevent the losses due to voltage drop if we are transmitting the voltage signals over long distances ,the effective wire resistance could change the actual value we use 4-20 mA because the strength of the noise signal is always less than 4 mA. by transmitting the current signal we can greatly reduce the voltage drops across the wire. In hazardous areas where field instruments are installed and where the signal through marshaling rack is coming and going moreover this electronic signal is changed into 3-15 psi instrument air which then operates the process valves located in field the minimum range of this signal is kept 4 mA so that the operation personnel in control room may differentiate between low or no signal means 4 mA is a low signal and 0 mA is no signal(means ...

RS 232 is peer to peer connection RS –stands for recommended standard RS232-fullduplex 3 wire (transx,recievx,signal ground) It support one master one slave Its work like hand shaking principle(send & receive alternatively) It communicate up to 15mts RS422 is extension of RS232 Full duplex 4 wire (T+, T-, R+, and R-) It support (communicate)upto 10 devices It communicate up to 1200mts RS 485 half duplex 2 wire (D+, D-) It support up to 31 devices It communicate up to 1200mts