Process Instrument & Analyzers
Process Instrumentation is used to monitor and control the process plant in the oil, gas and petrochemical industries. Instrumentation ensures that the plant operates within defined parameters to produce materials of consistent quality and within the required specifications.
Instrumentation includes sensing devices to measure process parameters such as pressure, temperature, liquid level, flow, velocity, composition, density, weight; and mechanical parameters and electrical parameters such as vibration, position, power, current and voltage
Pressure Transmitter / Pressure sensors / Pressure gauges / Rupture (bursting) discs
Temperature Transmitter / Temperature sensors / Temperature gauges (Thermocouples or Platinum Resistance Temperature Detectors (RTDs))
differential pressure level meters, radar, magnetostrictive, nucleonic, magnetic float and pneumatic bubbler instruments
Flow measuring devices (FE) include vortex, positive displacement (PD) differential pressure (DP), Coriolis, ultrasonic, and rotameters
Analyzer Instrumentation: A wide range of analysis instruments are used in the oil, gas and petrochemical industries.
- Chromatography– to measure the quality of product or reactants
- Density (oil) – for custody metering of liquids
- Dewpond(water dew point and hydrocarbon dew point) to check the efficiency of dehydration or dewpoint control plant
- Electrical conductivity– to measure the effectiveness of potable water reverse osmosis plant
- Oil-in-water – prior to discharge of water into the environment
- pH of reactants and products
- Sulphur content – to check the efficiency of gas sweetening plant
- All type of Gas analyzers (Mono Gas Analyzer / Multi Gas analyzer)
Most instruments function continuously and provide a log of data and trends. Some analyser instruments are configured to alarm (AAH) if a measurement reaches a critical level.
Other Instrumentation: Major pumps and compressors are provided with vibration sensors (VT) to give operating personnel a warning (VA) of potential mechanical problems with the machine.
Rupture discs (PSE) and pressure safety valves (PSV) are self-actuated and provide no immediate indication that they have ruptured or lifted. Instrumentation such as pressure alarms (PXA) or movement alarms (PZA) may be fitted to indicate that they have operated.
Corrosion coupons and corrosion probes provide a local indication of corrosion rates of fluids flowing in piping.
Pipeline pig launchers and receivers are provided with a pig signaller (XA) to indicate that a pig has been launched or has arrived.
The fire and gas detection system comprises local sensors to detect the presence of gas, smoke or fire. These initiate alarms in the control room.
Older plant may have local control loops which operate pneumatic (3 – 15 psia) final element actuators. Sensors may also transmit electrical signals (4 – 20mA). Conversion between pneumatic and electrical signals is undertaken by P/I and I/P converters. Control of modern plant is based on a Distributed Control Systems(DCS) using Fieldbus digital protocols.