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DCS - Basic concept

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In  FERTILIZERS  AND CHEMICAL TRAVANCORE LTD (FACT)  there is a plant called RAP and its product is ammonia, there a lots of chain reactions taking place in the background.   And some of them in fact is very dangerous too… Take a small example, the constituents of ammonia, nitrogen and hydrogen are compressed to liquid we use big compressors for this process. Extreme care is required when dealing with these compressors, one should be very vigilant in monitoring the reading of pressure gauge, which shows the pressure of the inlet gas, the flow meter which indicates the flow if gas into the compressor, temperature of the steam which is used for running the compressor turbines, the pressure gauge at the outlet of the compressor. If any one among them shows an abnormal reading then there is some trouble with the process. In olden days the operators have to go into the field and manually carry out remedy measures, or if things the not coming in the right way , as a last
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Instrument Installation Philosophy

Instrument Installation Philosophy All work shall be of the highest quality craftsmanship and shall conform to the best applicable engineering practices, and, relevant codes referred in the bid document. All instruments shall be installed in a neat workmanlike manner ensuring ease of operation and maintenance. The Contractor shall prepare hook-up and installation detail drawings regarding each type of instrument for the Company’s approval, and shall carry out the installation in accordance with these approved drawings. The Contractor shall install instruments and equipment with due consideration of the following: 1. No instrument with the exception of pressure gauges and temperature indicators, shall be installed in such a way that it depends on its impulse piping or electrical connections for its support. 2. Positioning of equipment shall not constitute a safety hazard. Where possible, instruments shall be mounted so that they are protected fr
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Instrument Material Selection Philosophy

Instrument Material Selection Philosophy All materials and equipment furnished shall be new and unused, of current manufacture and the highest grade and quality available for the required service, and free of defects. Materials shall be selected with regard to the following criteria: 1. Suitability for the specified process conditions, with SS 316 as the minimum for use outside pressurized rooms, except for salt-water service . 2. Suitability for the corrosive effects of the atmosphere. 3. Galvanic compatibility between dissimilar materials, with isolating bushes, plates, used where necessary to prevent corrosion due to galvanic action. 4. Wherever process condition demands NACE quality Instrument fittings, the same shall be provided as per NACE, latest standard with appropriate material. For non NACE application, material for fitting shall be appropriate for relevant process fluid with SS-316 as minimum. 5. Company approval shall be obtained
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Instrument Power System Philosophy

Instrument Power System Philosophy 1. Pneumatic Supply For pneumatic instruments, dry instrument gas / air supply shall be as follows: - 5.5 Kg/cm 2  (min.) - 7.5 Kg/cm 2  (nor.) - 10.5 Kg/cm 2  (max.) 2. Electric Power Supply Components of power supply system shall be of highest available quality for reliability and long service life. Power supplies for all transmitters, controllers, signal converters, electric system and components in shutdown system shall be supplied from uninterruptible power supplies. Power distribution to each consumer shall be through proper, independent switch and fuse. Protective fuses shall be of indicating cartridge type mounted in fuse holders. In general, the following Power Supplies shall be used for instrumentation and Control: - For Process Platforms: 110V AC + 5%, 50HZ + 1% (UPS) for all instruments control. However, all components / instruments / system shall be suitable for 110 V + 10% AC, 50 Hz + 3% - Fo
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