Procedure and plans for safe plant operation: 1. Starting sequence should be well defined, written and known to the workers involved in this work. 2. Starting in sequence of utilities like water, air, power; purging, charging, slow and gradual heating, monitoring of pressure, temperature, flow and reaction rate, cooling if necessary, starting of exhaust system, scrubber or condenser etc., observing noise, vibration, speed, alignment, synchronizing etc. are all important. 3. During start-up if drains remain open, vent valves remain closed, wrong valves are operated, unwanted material enters e.g. oxygen instead of nitrogen as blanketing over flammable reaction, water where it is incompatible, air instead of steam or steam instead of air, excess or less charging of material or catalyst, delayed cooling or heating, not starting of any pump or instrument, no indication or alarm due to failure or malfunctioning of instrument in the beginning, no starting of local exhaust or scrubber when it is essential and failure of interlock or trip resulting in unwanted mixing or reaction, mixing of air with hydrocarbons, contacting hot oil and water, thermal or mechanical shocks etc. are some of the examples of possible disorders. 4. Correct identification of pipelines, valves and gauges, correct sequence of control operation, correct charging or addition-rate and instead of relying on instruments only Counter-check of other parameters and strict manual observation and satisfaction are requisite precautions for safe start-up procedure. 5. Attention should be paid on preparatory activity, verifying content, removal of air or venting, purging and disposal of purged material, removal or addition of water, slow and sequential starting of heating or cooling, gradual reaching of working parameters and normal operation. 6. Other points needing attention in start-up are removal of shutdown blinds, providing running blinds, opening of scrubber or discharge line valve, opening of isolation valve before safety valve, starting of local exhaust ventilation, pump cooling and priming, readiness of firefighting equipment, leak detection, opening vents and drains before allowing steam in the system, partial opening of steam valves, introducing steam from the bottom part, observance of level and overflow if any, safe increase in loading, avoidance of incompatible material, avoidance of moisture and impurities in breathing air, purging of blow down tanks and flare, removing air from vacuum equipment, inspecting joints and valves for leakage, verifying steam traps working for condensate discharge, safe displacement of steam, water or purge gas after their use, removing residual water before, introducing hot oil (initially cold oil should be introduced), using heat-exchanger for indirect and gradual heating or cooling etc.