INSTRUMENTSInstruments are used for continuous monitoring and controlling the process variables such as 1.Flow 2.Pressure 3.Level 4.TemperatureAnd also Controlling devices &various Analytical Equipments

EDWIN SELVARAJ

TOPICS 1.Flow Measurement 2.Pressure Measurement 3.Temperature Measurement 4.Level Measurement 5.Control Valve 6.Control Valve Accessories 7.Control Loops 8. Analytical Instruments 9.Detector-Fire & Gas 10.Instruments Calibration 11.Codes, standards & Specification 12.Instruments Symbols 13.Regulators 14.Pressure Relief Valve 15.Surge Controls

EDWIN SELVARAJ

FLOW MEASUREMENT

1.Flow Transmitter2.Flow Switch3.Flow gaugeHOME

EDWIN SELVARAJ

FLOW RATEFlow Rate Flow rate is an indication of how fast a substance moves through a conduit from one place to another. Flow rate is usually expressed as Volume flow rate & Mass flow rateVolume Flow Rate represents the volume of fluid that passes a measurement point over a period of time. An example measurement unit is kg per hour. The volume flow rate can be calculated if the average flow velocity and inside pipe diameter are known. The calculation is based on the formula Q = A x vwhereQ = volumetric flow rateA = cross-sectional area of the pipe v = average flow velocity (flow rate)Mass Flow Rate represents the amount of mass that passes a specific point over a period of time. Mass flow rates are used to measure the weight or mass of a substance flowing through a process operation. If the volumetric flow rate and density are known, the calculation is based on the formulaW = Q x rwhereW = mass flow rateQ = volumetric flow rater = density (r = density rho )

EDWIN SELVARAJ

FLOW

EDWIN SELVARAJ

5 Port Manifold

EDWIN SELVARAJ

DP TRANSMITTER PARTS

1.COVER2.O-RING, COVER14 & 15.PLUG,DRAIN/VENT 18.O-RING,PROCESS FLANGE19.MODULE,SENSOR20.O-RING,FLANGE ADAPTOR21.FLANGE ADAPTOR24.PCB,ELECTRONICS

EDWIN SELVARAJ

FLOW ELEMENT

Differential PressureOrifice Plate PitotVenturiAdvantages: Simple, no moving partsDisadvantages: Susceptible to wear in dirty services except vertically Orifice edge sharpness affects accuracy

EDWIN SELVARAJ

ORIFICE FLOW MEASUREMENTDP TR

EDWIN SELVARAJ

FLOW ELEMENT

VORTEX Bluff Body Advantages: No moving parts Disadvantages: Bluff body can corrodeTURBINE

RotorAdvantages: Accuracy Disadvantages: Moving parts can wear

EDWIN SELVARAJ

FLOW ELEMENTFlow Element Positive Displacement (PD) Oval Gear Sliding Vane Nutating DiskDisadvantages: Many moving parts subject to wear Prefilters for dirty service

Mass Coriolis Thermal MassAdvantages: Very low maintenance (Coriolis) No moving parts, corrosive fluid may effect element (Thermal Mass)Magnetic Field (EMF METER) AC Field DC Field Advantages: Low maintenance element Very low maintenance

EDWIN SELVARAJ

TURBINE FLOWMETR Fluid enters the turbine meter trough the flow conditioner which imposes an evenly distrubuted pattern on the flow striking on the turbine wheel. The blades of the rotor are positioned under an angle 30 to 40 deg. The fluid passes through the turbine, causing the turbine to rotate at a speed proportional to fluid velocity. As each turbine blade cuts the magnetic field generated by the meter's magnetic assembly, a pulse induces in the pick-up coil.These pulses provide an output frequency that is proportional to volumetric flow.What is the most common problem with the meters? Debris. Debris getting into the meter body may cause readings to be too high, too low, or result in no readings at all. This problem may be solved with the use of a filter or strainer upstream of the meterFlowFlow

EDWIN SELVARAJ

Magnetic FlowmeterThe operating principle of the magnet flow tube is based on FARDAYS LAW of electromagnetic induction, which states that voltage will be induced in a conductor moving through magnetic field. Faradays Law: E=kBDVThe magnitude of the induced voltage E is directly proportional to the velocity of the conductor V, conductor width D, and strength of the magnetic field B. The field coils placed on opposite side of the pipe generate magnetic field. The process liquid moves through the field with average velocity V, electrodes sense the induced voltage. The distance of the electrode is the width of the conductor. The two electrodes acting as +ve and ve element.

EDWIN SELVARAJ

Magnetic FlowmetersELECTRODEMAGNETIC COILELECTRODEFT

EDWIN SELVARAJ

VORTEX METER The operating principle of the Vortex Meter is based on the VAN KARMAN EFFECT. As fluid passes a bluff body, it seperates and generates small eddies or vortices that are shed alternately along and behind each side of the bluff body. These vortices cause areas of fluctuating pressure that are detected by the sensor. The frequency of vortex generation is directly proportional to fluid velocity.Fluid velocity = Vortex frequency / K-factor K-factor relates the frequency of vortex generation of fluid velocity

Flow

EDWIN SELVARAJ

ULTRA FM-Transit Time MethodThe meter use sound waves to determine the flowrate. Pulses from piezoelectric transducer travel through a moving fluid at speed of sound and provide an indication of flow velocity. 1. Transit-time method, in which two opposing transducers are mounted so that sound waves traveling between them are at 45 Deg. Angle to the direction of flow within a pipe. The speed of sound from upstream transducer to the downstream transducer represents the inherent speed of sound plus contribution due to the velocity. In a simultaneous measurement in the opposite direction a value is representative of the fluid velocity, which is linearly proportional to the flow rate.

EDWIN SELVARAJ

ULTRA FM-Doppler Method Doppler Effect- In this type two sensing elements mounted same side of the tube. A ultrasonic sound wave is transmitted into the fluid by one of the elements. Solids or bubbles in the fluid reflects the sound back to the receiver element. The difference between the transmitted frequency and receiving frequency and receiving frequency is directly proportional to the flow rate

EDWIN SELVARAJ

Ultrasonic Measurement Sound guided obliquely through the pipe cross-section Helix-shaped ultrasonic signal giving accurate integration via the whole profiletodayyesterday

EDWIN SELVARAJ

The new helix-shaped ultrasonic signalHigh measuring accuracy independent of flow profile Laminar-turbulent even in the cross-over area and also with laminar flow Even with high viscosities Even with small nominal diameters Even with small flow velocitiesAccuracy limits: 0,5 % at a 1 : 25 turndown 1 % at a 1 : 100 turndown

EDWIN SELVARAJ

Mass Flowmeter: CORIOLISTube Vibration: Coriolis meter are made up one or more vibrating tubes,usually bent. The fluid to be measured, travels through the tube. The fluid accelerates as it approaches the point of maximum vibration and decelerates as it leaves the point. As a result the tube takes twisting motion. The amount of twisting motion isDirectly proportional the mass flow. Positon detectors are usedto sense the position of vibrating tubesFlow

EDWIN SELVARAJ

Mass ProBar FlowmeterMass ProBar flowmeter measures static pressure, temperature and diff pr with only one tap into process line. One electronics packages integrated into the sensing probe is all that is required to sense DP, P, & Temp.

EDWIN SELVARAJ

Mass ProBar-Flow Element-Annubar

EDWIN SELVARAJ

VA Flowmeter-RotameterFT

EDWIN SELVARAJ

Flow switch A Flow switch is normally a simple device that monitors flow and sends a trip signal to another device such as a pump to protect it. Some flow switch applications are 1. Pump Protection 2. Cooling circuit protection 3. High and low flow rate alarm and general flow monitoring. Flow switch types are used on air, steam and liquid.

EDWIN SELVARAJ

SIGHT FLOW GAUGESight Flow Gauge provide the flow detection, and depending upon process , show variation in flow.Two Models:- Rotor Type & Paddle Type.HEADGASKETWINDOWFASTNERSPACERFLOW

EDWIN SELVARAJ

PRESSURE MEASURMENT 1.PRESSURE TRANSMITTER 2.PRESSURE GAUGE 3.PRESSURE SWITCH

TOPICS

EDWIN SELVARAJ

EDWIN SELVARAJ

Types of PressureDifferential Pressure: The difference in static pressure between two identical pressure taps at the same elevation located in two different locations in a primary device. Static Pressure: Pressure of a fluid whether in motion or at rest. It can be sensed in a small hole drilled perpendicular to and flush with the flow boundaries so as not to disturb the fluid in any way.Absolute Pressure: This is pressure exerted by a system having complete vacuum as ref point AP = Gauge Pr + Atmospheric PrAtmospheric pressure: This is pressure exerted by the Atmosphere surrounding the Earth and the ref point is sea levelGauge pressure: This pressure above Atmospheric. Represents positive difference between measured pressure and existing Atmospheric pressure. Line Pressure: P = F / AVacuum Pressure: Pressure below atmospheric

EDWIN SELVARAJ

EDWIN SELVARAJ

EDWIN SELVARAJ

DIFFERENTIAL PRESSURE ELEMENTS

EDWIN SELVARAJ

TRANSMITTER PARTSPRESSURE

EDWIN SELVARAJ

Pressure TransmitterLiquid level transmitterAbsolute-pressure transmitterPressure transmitterDifferential pressure and flow transmitter

EDWIN SELVARAJ

PT-Measuring PrinciplePressure acts on the separating diaphragmSilicone liquid (or an inert liquid) transmits the pressure to the sensorFour piezoelectric resistors in the measuring diaphragm in bridge connection change their resistance value - the bridge output voltage is therefore proportional to the pressureWith overload from one side the separating diaphragm closes upOverload protection due to large central diaphragmMeasuring cell for differential pressureMeasuring cell for pressureSeparating diaphragmCentral diaphragmSensor+_

EDWIN SELVARAJ

OperationCan be set on site or via digital communication (HART protocol, Profibus PA)Start of the scale and end of the scale can be set on site without setting the pressure (blind adjustment)Electrical dampingLoop check functionLinear/sq. root characteristic curve with differential pressure transmitterOutput signal in the case of error (3.6 mA or 22.8 mA)Key lockPlant-specific effects (position error, environ- mental influences) compensated at the press of a button

EDWIN SELVARAJ

Modular design

EDWIN SELVARAJ

Special materials allow a wide variety of applicationsDifficult applications in the chemical industry, petrochemicals, pharmacy, foodstuffs, power station, ...Stainless steel for 80% of all media found in industry Hastelloy C 276 for chloroacetic acid, formic acid, acetoneSITRANS P measuring cells are also suitable for critical media due to the use of special materials Monel for fluorides, cyanides, sea waterTantalum for phosphorus chlorides, sodium chloride, hydrochloric acidGold for hydrogen

EDWIN SELVARAJ

Connection of the HART CommunicatorField levelControl level4 ... 20 mASupply disconnectormin. 250 4 ... 20 mA + HART signalSmart supply disconnector

EDWIN SELVARAJ

with PROFIBUS-PAPROFIBUS-PA = PROFIBUS-DP communication and optimized transmission technology for field devicesPROFIBUS-PA for hazardous areasInterface acc. IEC 1158-2 and EN 50170Electronic current limiting acts without delay, prevents bus overloading and even guarantees data transmission with non-faulty stations in the case of a device error

EDWIN SELVARAJ

Seals:-For measuring aggressive, paste-like, or hot measured media and those containing solids -All kinds of seals available -With different types of connection (e.g. Clamp, flange etc.) Stopcock Supply disconnector

EDWIN SELVARAJ

Pressure GaugeC-Type Bourdon ElementPr Measur

EDWIN SELVARAJ

Pressure SwitchA pressure switch is an instrument that automatically senses change in the pressure and opens or closes an electrical switching element when predetermined pressure point is reached.Piezoelectric TypeBourdon TypeDiaphragm TypePressure

EDWIN SELVARAJ

Temperature MeasurementTOPICS

EDWIN SELVARAJ

EDWIN SELVARAJ

THERMOWELL

EDWIN SELVARAJ

THERMOWELLThermowells in conductive materials are used to separate the thermometer from the medium. Thermowell protect the thermometers from aggressive media and facilitate replacement of the thermometer. A thermowell is basically a hallow metal tube with one ended sealed. It is permently mounted in the pipe or vessel. The thermocouple inserted into the hallow U Length This length called as a immersion length of a well typically referred to as the U. The length is measured from the bottom of the threads or flange to tip of the well. Accuracy of the sensor can be affected by the immersion length of the well. A rule of thumb is to immerse a thermocouple at least 3 in gases and 1 in liquids. Add 2 this rule for RTDs.T Length- This length is between process connection and top end of the well

BORE SIZE will accommodate sheathed thermocouples, RTDs and thermometers.Reason for fails:1.Improper process application2.Improper material selection3.Improper Installation4.Higher than anticipated temperature5.Ignoring velocity considerations

EDWIN SELVARAJ

THERMOWELL THREADED WELLS are provided in one piece construction and have an NPTConnection.FLANGED WELLS consist of a stem welded to an ANSI rated flangeSOCKET WELD WELLS fit all ASAstandard couplingsand flanges areeasy to install and have a very tight fit

EDWIN SELVARAJ

THERMOWELLTEMP

EDWIN SELVARAJ

TEMPERATURE ELEMENTTEMP

EDWIN SELVARAJ

Types of Temperature element: Resistance Temperature Detector (RTD)Thermocouples Infrared radiators ThermistorsThermostates.Temperature Element

EDWIN SELVARAJ

Temperature ElementMeasuring principle-RTD-sensorsResistive temperature devices capitalize on the fact that the electrical resistance of a material changes as its temperature changes. They are suitable for the measurement of temperatures between -200 C and approx. 800 C and stand out due to high measurement accuracy and long-term stability. The resistance sensor element most frequently used is a Pt100 which has a nominal value of 100 at 0 C.As their name indicates, RTDs rely on resistance change in a metal, with the resistance rising more or less linearly with temperature

EDWIN SELVARAJ

RTDAdvantages:- 1.The response time is very fast2.Comparing T/c RTD will not having drift problems.3.Within range RTD is more accurate and higher senstivityDisadvantages:- 1.More expensive than T/c2.RTD not cabaple of measuring wide rangeOuter Sheath MaterialResistance Temperature Detector (RTD)Resistive temperature devices capitalize on the fact that the electrical resistance of a material changes as its temperature changes. As their name indicates, RTDs rely on resistance change in a metal, with the resistance rising more or less linearly with temperature

EDWIN SELVARAJ

THERMO COUPLETwo conductors of different metals are twisted at one end. This end called hot junction. The other end is open end. When a circuit is formed by a junction of two dissimilar metals and the junctions are held at different temperatures, a current will flow in the circuit caused by the difference in temperature between the two junctions.Advantages:- 1.Inexpensive2.Quick Response Time.3.Self-Powered4.Multi point sensingDisadvantages:- 1.Non-Linear2.Low sensitivity3.Less stable than RTDs4.Requires T/c extension wire

EDWIN SELVARAJ

Types of thermo couple

THERMOCOUPLEEXTENSION WIREMATERIALISAMATERIALCOLOR OF INSULATION+VE-VESYM+VE-VE+VE-VEOVERALLCopperConstantanTCopperConstantanBlueRedBlueIronConstantanJIronConstantanWhiteRedBlackChromelAlumelKChromelAlumelYellowRedYellowChromelConstantanEChromelConstantanPurpleRedPurple

EDWIN SELVARAJ

Thermo couple Temp Range

THERMOCOUPLEEXTENSION WIREMATERIALISAMATERIALTemp Range+VE-VESYM+VE-VECopperConstantanTCopperConstantan-200 C Deg350 C DegIronConstantanJIronConstantan0 C Deg760 C DegChromelAlumelKChromelAlumel-200 C Deg1250 C DegChromelConstantanEChromelConstantan-200 C Deg900 C Deg

EDWIN SELVARAJ

Resistance bulbs shall be selected in accordance with the following:Resistance bulbs should be used when the working temperature is between -200oC and 400oC, and precise measurement is required.

Bulbs shall be fitted with platinum resistance elements. And normally R0= 100 ohms

Thermistors are based on resistance change in a ceramic semiconductor; the resistance drops nonlinearly with temperature rise.

Strain Gage: A measuring element for converting force, pressure, tension, etc., into an electrical signal.

Wheatstone Bridge: A network of four resistances, an emf source, and a galvanometer connected such that when the four resistances are matched, the galvanometer will show a zero deflection or "null" reading.

Temperature Measurement

EDWIN SELVARAJ

IR THERMOMETERSIR Thermometers / pyrometers by specifically measuring the energy being radiated from an object in the 0.7 to 20 micron wavelength range, are subset of radiation thermometers. These device can measure this radiation from a distance. There is no need direct contact of the object as in the case of T/C or RTD.

EDWIN SELVARAJ

ThermostatsThermostats are switches which maintain a pre-determined temperature within certain limits by automatically opening and closing an electrical contact.

MODE OF OPERATION: Temperature changes in the closed capillary-tube system lead to changes in the vapor pressure of the charge. The pressure operates a snap action electrical contact via a bellows.

EDWIN SELVARAJ

Fluid-expansion devices:

Typically like household thermometer, generally come in two main classifications: - mercury type- organic-liquid type

Versions employing gas instead of liquid are also available.

Temperature Measurement

EDWIN SELVARAJ

Field-Mounted ThermometersRanges for field-mounted thermometers shall be selected such that normal operating temperature is around 60% of the full scale.TEMP EL

EDWIN SELVARAJ

TT- A temperature transmitter is a device that captures a signal from a sensor such as a thermocouple or RTD, calculates the temperature based on this signal, and then converts it to a 4-20 mA, FOUNDATION fieldbus, or some other type of signal for output to a receiving device. TTEMP

EDWIN SELVARAJ

Temperature Transmitter-Parts

EDWIN SELVARAJ

LEVEL MEASUREMENTTOPICS

EDWIN SELVARAJ

EDWIN SELVARAJ

LEVEL TRANSMITTERTYPE OF LEVEL TRANSMITTER - Differential Pressure Torque Tube Displacer- Bubbler Tube Hydrostatic Ultrasonic Nuclear Guide Wave Radar Servo / Tank Gauge Pulse Burst Radar RF Capacitance Magnetostrictive Vibration Buoyancy Magnetic Level Indicator LEVELevel

EDWIN SELVARAJ

Principle of operation: Archimedes Principle, that states that a body immersed in a fluid is buoyed up by a force equal to the weight of the displaced fluid. It operates according to the fully proven liquid displacement and torque tube principles. A change in the liquid level varies the net weight of the displacer, increasing or decreasing the load of the torque tube by an amount directly proportional to the change in liquid level. The subsequent rotation of the torque tube rod is used to modify the magnetis field around Hall effect sensor, producing signal proportional to level in the vessel.It can also function as a local level controller.LT

EDWIN SELVARAJ

SERVO GAUGEA small displacer suspended by a strong, flexible measuring wire. This gauge uses a electrical servo motor to raise or lower the displacerRADAR GAUGE

EDWIN SELVARAJ

Level MeasurementBubbler Type

EDWIN SELVARAJ

Level Tr-Ultrasonic TypeUse of non-contact instruments should be considered for applications in corrosive toxic highly viscous slurries & heavy or irregularly shaped bulk materials or where probes can be damaged by the process.The ultrasonic level metering technology is based on the principle of the time required for the ultrasonic wave to travel from the source to the top surface of the level to be measured and back. On the basis of this time, this device calculates the level. TransmitterTop of the SurfaceUltrasonic Waves

EDWIN SELVARAJ

Level Measurement Nuclear TypeNuclear instruments have a radiation source and detector. The sourceradiates the signal through the vessel to the detector. The mass in the vesselabsorbs the radiation and blocks a percentage of it from reaching thedetector.A design involving nuclear instruments needs to provide a way to shield the source, the ability to lock out the source, and the posting of warning signs.

EDWIN SELVARAJ

A magnetic gauge is a metal tube with aninternal float magnetically coupled to anindicator on as scaleon the outside of the tube.

Magnetic gauges should be considered asan alternative to glass for flammable,corrosive, toxic, high pressure, hightemperature, or long visible length service.

The installation of the magnetic level gaugeshould be the same as for glass level gauges.The exception is that the end connection should be flanged.

Magnetic gauges should not be used for liquidsContaining dirt or suspended solids. Dirt cancause the float to stick resulting in falseindications. The float in a magnetic gaugeis engineered for a certain range of liquiddensities.

Magnetic Gauges

EDWIN SELVARAJ

MAGNETIC GAUGEA hermetically sealed float with an internal magnetic ring is housed in a non-magnetic float chamber. The float move up and down in the chamber as level rises or falls. A magnetic highly visible shuttle or bargraph indicator encapsulated in a hermetically sealed glass tube, is attached in a scale housing to the outside of the float chamber. It indicates the level without being in contact with the process fluid.

EDWIN SELVARAJ

GAUGE GLASSTRANSPARANT-For dark dirty liquidsREFLEX-For clear liquidsParts:- 1.Centre Piece 2.Sealing Joint 3.Refles Glass 4.Cushion Joint 5. Cover Plate 6.U-Bolts with nutsTopics

EDWIN SELVARAJ

LEVEL SWITCH-The float element suspended in a rode with spring. The spring will be extended to a known length, controlled by a mechanical stop to prevent overstressing. Attached to the spring is a rod and magnet assembly, free to move up and down as the spring extends or contracts within the pressure tube.As liquid raises to cover the element, due to loss of weight causing the spring to contract, hence the magnet moving upwards and actuating switch mechanism.On falling of level the operation is vice-versa.

EDWIN SELVARAJ

LEVEL SWITCH-Vertical float : A permanent magnet (1) is linked to switch mechanism (2). As the float (3) rises following liquid level, it raises the attraction the sleeve (4) into the field of the magnet, which in turn snaps against the non-magnetic enclosing tube (5) releasing the switch actuating arm and changing the switch contact state. The enclosing tube provides a static seal between the switch mechanism and the float. When the level falls the float pulls the attraction sleeve down below the magnetic field. The magnet swings out to reverse contact position causing low level switch actuation.

EDWIN SELVARAJ

LEVEL SWITCH-Float Side Mounted-Side mount units employ permanent magnetic force as the only link between the float and the switching element. As the pivoted float follows liquid level changes it moves attraction sleeve (1) into or out of the field of a switch-actuating magnet (2) causing switch operation. A non-magnetic enclosing tube (3) effectively isolates the switch mechanism from the controlled liquid.

EDWIN SELVARAJ

LEVEL SWITCH-Displacement

EDWIN SELVARAJ

LEVEL SWITCH-Displacement

EDWIN SELVARAJ

EDWIN SELVARAJ

LEVEL SWITCH-Vibration / Fork

The Turning fork is piezoelectrically energised and vibrates at its mechanical resonance frequency appo. 1200 Hz. When the turning fork is immersed in the product the frequency changes. The change is detected by integrated oscillator and converted into a switching command.

EDWIN SELVARAJ

LEVEL SWITCH-Capacitive Type In the detection system is based on the capacitive principle, where the probe and vessel wall together form a capacitor. The area between the probe and the wall is either filled with air (vessel empty) or the material to be measured (vessel full) according to the product level. The initial capacitance of an empty vessel is much smaller than that of a full vessel, the maximum capacitance being a function of the dielectric constant of the material. This change in capacitance between the initial and final capacitance values activates the switch at a preset level.

EDWIN SELVARAJ

LEVEL SWITCH-ConductiveA low voltage AC signal is applied between the sensing probe and ground. The very small current is conducted between the two when the process liquid touches the sensing probe. The current flow is sensed by an electronics network which actuates the output relay.

EDWIN SELVARAJ

LEVEL SWITCH-PADDLE

Level Sw

EDWIN SELVARAJ

CONTROL VALVE

&

ACTUatOR

TOPICS

EDWIN SELVARAJ

Common Types of Valve

EDWIN SELVARAJ

Common Types of Valve

EDWIN SELVARAJ

Common Types of Valve

EDWIN SELVARAJ

EDWIN SELVARAJ

EDWIN SELVARAJ

Common Types of Valve

EDWIN SELVARAJ

CONTROL VALVE

EDWIN SELVARAJ

ACTUATORRotary ActuatorQ-Turn Actuator

EDWIN SELVARAJ

Pneumatic ActuatorThe pneumatic actuatorsare often simple deviceswith a minimum mechanical parts, used on linear or Q-turn valves. Sufficient air pressure acts on a piston or diaphragm to provide thrust in a linear motion for gate or globe valves. Alternatively, the thrust may be mechanically converted to rotary motion to operate the Q-turn valves.

EDWIN SELVARAJ

Electric Actuator

EDWIN SELVARAJ

Spring Return ActuatorSpring Return Actuator (ESD)

EDWIN SELVARAJ

Rack & Pinion Actuator

EDWIN SELVARAJ

Bonnet & Packing Box

EDWIN SELVARAJ

CONTROL VALVEACTUATORYOKEI to P CONVERTORVALVE POSITIONERVALVE BODYAFR

EDWIN SELVARAJ

TYPE OF CONTROL VALVES Piston Type Actuated valve Diaphragm Actuated Linear ValveDiaphragm ActuatedRotary Valve

EDWIN SELVARAJ

Control Valve Parts

EDWIN SELVARAJ

CONTROL VALVE

EDWIN SELVARAJ

Q-Turn Valve Body + Rotary Actuator Assembly

EDWIN SELVARAJ

Butterfly Valve

EDWIN SELVARAJ

Valve Bodies

EDWIN SELVARAJ

Cv is numerically equal to the number of U.S. gallons of water at 60F that will flow through the valve in one minute when the pressure differential across the valve is one pound per square inch.

Cv varies with both size and style of valve, but provides an index for comparing liquid capacities of different valves under a standard set of conditions. DEFINE CV OF A CONTROL VALVE?

EDWIN SELVARAJ

VALVE PLUGS ACCORDING TO FLOW CHRACTERISTICSFor blow down and vent servicesFor Compressor surge controlsFor feed streamsservices

EDWIN SELVARAJ

VALVE FLOW CHRACTERISTICS

EDWIN SELVARAJ

The linear characteristic valve plug is shaped so that the flow rate is directly proportional to the valve lift (H), at a constant differential pressure. A linear valve achieves this by having a linear relationship between the valve lift and the orifice pass area (see Figure below).For example, at 40% valve lift, a 40% orifice size allows 40% of the full flow to pass. LINEAR CHRACTERISTICS

EDWIN SELVARAJ

These valves have a valve plug shaped so that each increment in valve lift increases the flow rate by a certain percentage of the previous flow. The relationship between valve lift and orifice size (and therefore flow rate) is not linear but logarithmic.

Table below shows how the change in flow rate alters across the range of valve lift for the equal percentage valve with a rangeability of 50 and with a constant differential pressure. EQUAL % CHRACTERISTICS

EDWIN SELVARAJ

EQUAL % CHRACTERISTICSCV

EDWIN SELVARAJ

Valve Accessories1. Air Filter Regulator 2. I/P Transducer 3. Positioner4. Volume Booster5. Solenoid6. Limit / Proximity Switch7.Position TransmitterTOPICS

EDWIN SELVARAJ

I/P Transducer:I/P Transducer: Transducers convert a current signal to a pneumatic signal. The most common transducer converts a 4-20 mA electric signal to a 3-15 psig pneumatic signal.Valve Access

EDWIN SELVARAJ

Volume BoosterVolume Boosters are used on throttling control valves to provide fast stroking action with large input signal changes. At the same time, the flow boosters allow normal Positioner air flow (and normal actuation) with small changes in the Positioner input signal. Depending on actuator size, packing set and the number used, boosters can decrease valve stroking times up to 90 percent.

Valve Acces

EDWIN SELVARAJ

Air Filter Regulator A pressure reducing regulator maintains a desired reduced outlet pressure while providing the required fluid flow to satisfy a downstream demand. The pressure which the regulator maintains is the outlet pressure setting (setpoint) of the regulator. A downstream pressure increase above the outlet pressure setting moves the diaphragm assembly off the stem venting the excess pressure through a hole drilled or tapped in the spring case.Valve Access

EDWIN SELVARAJ

Valve Positioner The input signal from the control device is connected to the bellows. When the input signal increases the bellows expands and moves the beam The beam pivots about the input axis moving the flapper closer the nozzle. The nozzle pressure increases and through the relay action increases the output pressure to the actuator. The pressure increases in the actuator causes the stem move downward. Stem movement is fed back to the beam by means of the cam. As the cam rotates the beam pivots about the feedback axis to move the flapper slightly away from the nozzle. The nozzle pressure decreases, in turn pressure to the actuator reduced. This process continues until the equilibrium is reached.

EDWIN SELVARAJ

Digital Valve ControllerValve Ass

EDWIN SELVARAJ

SOLENOID VALVE are used wherever fluid flow has to be controlled automatically. SOV are control units, when electrically energized or de-energized, either shut-off or allow fluid to flow.The actuator takes the form of an electromagnet. When energized a magnetic field builds up which pulls a plunger or pivoted armature against action of a spring. When de-energized plunger or pivoted armature is returned to its original position by the spring action.Valve Acces

EDWIN SELVARAJ

Proximity / Limit SwitchLimit switch:-Limit switches are contact typewhich are used to indicate thevalve position whether open or closeProximity switch:-a non-contact type.Valve AccesValve Acces

EDWIN SELVARAJ

Proximity / Limit Switch

EDWIN SELVARAJ

Position TransmitterValve Acces

EDWIN SELVARAJ

RecordersFor all Applications in Process Engineering Standards/certificates CE marking NAMUR NE KTA 3503The low-cost multipoint recorder with 6 channelsThe recorder with text and front-mounted PC interfaceThe multifunctional unit with backlit displayThe communicative unit with RS 485 interface

EDWIN SELVARAJ

Line Recorders with Alphanumeric Output1, 2, 3 channels, DC U/I, or DC U/I, TC, RTD, RTwo additional digital channelsGrid-free chart (LA)Input/output module (also relay)Pen-Lift

EDWIN SELVARAJ

New Multipoint Recorder with Backlit Display 6 channels, DC U/I, TC Backlit display Two additional digital channels Grid-free chart Input/output module (also relay) Remote control (infrared)

EDWIN SELVARAJ

Simple Programming with SIPROM

Software SIPROM R forSIREC LA/PASIREC PUVARIOGRAPH Uniform operating conceptIndication of current measuring data in online operationPrintout of parameter data and instrument tag data

EDWIN SELVARAJ

INSTRUMENT CONTROL LOOPTOPICS

EDWIN SELVARAJ

CONTROL LOOPPrimary Element: The measuring element that quantitatively converts the measured variable energy into a form suitable for measurement. Note: The sensing portion is the primary element for transmitters that do not have external primary elements.

Transmitter: A transducer which responds to a measured variable by means of a sensing element, and converts it to a standardized transmission signal which is a function only of the measured variable.

Controlled Variable: A variable the value of which is sensed to originate a feedback signal. (Also known as the process variable.)

Controller: A device which operates automatically to regulate a controlled variable.

Controller Algorithm (PID): A mathematical representation of the control action to be performed.

Set Point: An input variable which sets the desired value of the controlled variable.

EDWIN SELVARAJ

CONTROL LOOP

EDWIN SELVARAJ

CONTROL LOOPError In process instrumentation, the algebraic difference between the real value and ideal value of the measured signal. It is the quantity which when algebraically subtracted from the indicated signal gives the ideal value.

Manipulated Variable A quantity or condition which is varied as a function of the algebraic error signal so as to cause a change to the value of the directly controlled variable.

Feedback Control Control action in which a measured variable is compared to its desired value to produce an actuating error signal which is acted upon in such a way as to reduce the magnitude of the error.

Cascade Control Control in which the output of one controller is introduced as the set point for another controller.

EDWIN SELVARAJ

Proportioning Band: A temperature band expressed in degrees within which a temperature controller's time proportioning function is active.

Proportioning Control plus Derivative Function: A time proportioning controller with derivative function. The derivative function senses the rate at which a system's temperature is either increasing or decreasing and adjusts the cycle time of the controller to minimize overshoot or undershoot.

Proportioning Control plus Integral: A two-mode controller with time proportioning and integral (auto reset) action. The integral function automatically adjusts the temperature at which a system has stabilized back to the set point temperature, thereby eliminating droop in the system.

Proportioning Control with Integral and Derivative Functions: Three mode PID controller. A time proportioning controller with integral and derivative functions. The integral function automatically adjusts the system temperature to the set point temperature to eliminate droop due to the time proportioning function. The derivative function senses the rate of rise or fall of the system temperature and automatically adjusts the cycle time of the controller to minimize overshoot or undershoot. CONTROL LOOP

EDWIN SELVARAJ

FEEDBACK CONTROL LOOPS

EDWIN SELVARAJ

FEEDBACK CONTROL LOOPS

EDWIN SELVARAJ

MASS FLOW CONTROL LOOPLOOP

EDWIN SELVARAJ

What is HART?HART ("Highway Addressable Remote Transducer") is a communication protocol designed for industrial process measurement and control applications. It's called a hybrid protocol because it combines analog and digital communication. It can communicate a single variable using a 4-20 ma analog signal, while also communicating added information on a digital signal. The digital information is carried by a low-level modulation superimposed on the standard 4-to-20 mA current loop. The digital signal does not affect the analog reading because it's removed from the analog signal by standard filtering techniques.

TOPICS

EDWIN SELVARAJ

Transmitters - Calibration

How to use HART?

EDWIN SELVARAJ

Calibration: The process of adjusting an instrument or compiling a deviation chart so that its reading can be correlated to the actual value being measured.

Accuracy: The closeness of an indication or reading of a measurement device to the actual value of the quantity being measured. Usually expressed as percent of full scale.

Error: The difference between the value indicated by the transducer and the true value of the measurand being sensed. Usually expressed in percent of full scale output.

Repeatability: The ability of a transducer to reproduce output readings when the same measurand value is applied to it consecutively, under the same conditions, and in the same direction. Repeatability is expressed as the maximum difference between output readings.

Range: Those values over which a transducer is intended to measure, specified by its upper and lower limits.

INSTRUMENT CALIBRATION

EDWIN SELVARAJ

Span: The difference between the upper and lower limits of a range expressed in the same units as the range.

Rangeability: The ratio of the maximum flowrate to the minimum flowrate of a meter.

Duplex Wire: A pair of wires insulated from each other and with an outer jacket of insulation around the inner insulated pair.

Excitation: The external application of electrical voltage current applied to a transducer for normal operation.

Explosion-proof Enclosure: An enclosure that can withstand an explosion of gases within it and prevent the explosion of gases surrounding it due to sparks, flashes or the explosion of the container itself, and maintain an external temperature which will not ignite the surrounding gases.

Intrinsically Safe: An instrument which will not produce any spark or thermal effects under normal or abnormal conditions that will ignite a specified gas mixture. INSTRUMENT CALIBRATION

EDWIN SELVARAJ

INSTRUMENT CALIBRATION

Field InstrumentOutput Signal generated byCheck PointsRemarksD/P Instrument,Low Pressure InstrumentHand operated air pump or regulated air, and manometer or precision type test indicator0, 50, 100% of span, both increasing and decreasingCheck output signal against receiver instrument indicationVariable Area Meter type TransmitterTransmitting mechanism actuated by hand0,50,100% of span, both increasing and decreasingCheck output signal against receiver instrument indicationPressure InstrumentDead weight tester, or regulated air and precision type test indicator0, 50, 100% of span, both increasing and decreasingCheck output signal against receiver instrument indicationPressure SwitchDead weight tester, or regulated air and precision type test indicatorSet point only & differentialCheck alarm light, solenoid valve, sequence and interlock etc.

EDWIN SELVARAJ

INSTRUMENT CALIBRATION

Field InstrumentOutput Signal generated byCheck PointsRemarksPressure Gauge, Draft Gauge-----Atm. Pressure-----Field Temperature Transmitter(mV/E, R/E etc.)mV source, resistance source and precision type test indicator0, 50, 100% of span both increasing and decreasingCheck output signal against receiver instrument indicationThermometerTemperature bathAmb. Temperature Thermometer shall be checked with a temp. bath and a standard thermometer.------Displacer Type Level InstrumentImmersing the displacer in water0,50, 100% of span both increasing and decreasingCheck output signal against receiver instrument indicationBall Float Type LevelActuating the switch mechanically-----Check alarm light, solenoid valve, sequence and interlock, etc.

EDWIN SELVARAJ

INSTRUMENT CALIBRATION

Field InstrumentOutput Signal generated byCheck PointsRemarksTank GaugeRaising the float mechanically or electrically(1) Zero point(2) Smooth flat movement(1) Check receiver instrument indication(2) Prior to checking, the tank level must be confirmed as zeroControl Valve(Controller Output)Controller manual output0, 50, 100% of the valve stroke, both increasing and decreasing(1) Check the valve stroke against the travel indicator(2) Check the valve action at air failure(3) Check that the valve accessories, limit switch, AFR, function correctly.(4) Confirm the closing point of control valve stroke(5) Check alarm light, solenoid valve, sequence and interlock etc.

EDWIN SELVARAJ

Connection SizesConnection sizes for instruments shall conform to the values shown in Table 8.TABLE 8

INSTRUMENT PROCESS CONNECTIONS

TYPEPROCESS CONNECTIONS / SIZEPneumatic SignalsNPT 1/4 in female / 6mm / 8 mmElectronic Signals(Weatherproof or Explosion proofNPT 1/2 in femaleDifferential Pressure Instruments(Pressure Connection)NPT in femaleDiaphragm 2 or 3 in; FlangedThermowellFlangedGeneral Service1 in High Velocity Service1 1/2 in WeldedGeneral Service1 inHigh Velocity Service1 1/2 inScrewed3/4 in (male) Vessel2 inPressure Instruments---NPT 1/2 in femaleDiaphragm2 FlangedPressure gauges (Bourdon)---NPT 1/2 in femaleDiaphragm2 FlangedDraft GaugesNPT 1/4 in female

EDWIN SELVARAJ

Connection SizesConnection sizes for instruments shall conform to the values shown in Table 8.TABLE 8

INSTRUMENT PROCESS CONNECTIONSINST CAL

TYPEPROCESS CONNECTIONS / SIZELevel InstrumentsFlange TypeDifferentialPressureInstrumentDiaphragm2 FlangedDP TransmittersNPT 1/2 in femaleDisplacerExternalInternal2 Flange4 FlangeGauge Glass3/4 in

EDWIN SELVARAJ

PRESSURE REGULATORS

TOPICSTopics

EDWIN SELVARAJ

PRESSURE REGULATORS Specific Regulator Types Pressure reducing regulators Backpressure regulators Pressure switching regulators Vacuum regulators and breakers Blanketing Gas Regulator

EDWIN SELVARAJ

Pressure Reducing Regulators A pressure reducing regulator maintains a desired reduced outlet pressure while providing the required fluid flow to satisfy a downstream demand. The pressure which the regulator maintains is the outlet pressure setting (setpoint) of the regulator.The two types Regulators1. Direct-Operated (also called Self-Operated) 2. Pilot-Operated

EDWIN SELVARAJ

Direct-Operated (Self-Operated) RegulatorsIn operation, a direct-operated, pressure reducing regulator senses the downstream pressure through either internal pressure registration or an external control line. This downstream pressure opposes a spring which moves the diaphragm and valve plug to change the size of the flow path through the regulator.

EDWIN SELVARAJ

Pilot-Operated Regulators Pilot-operated regulators are preferred for where precise pressure control is required. This is two path control system. In two-path control, the main valve diaphragm responds quickly to downstream pressure changes, causing an immediate correction in the main valve plug position. At the same time, the pilot diaphragm diverts some of the reduced inlet pressure to the other side of the main valve diaphragm to control the final positioning of the main valve plug.Two-path control results in fast response.

EDWIN SELVARAJ

Vacuum Regulators and Breakers Vacuum regulators and vacuum breakers are devices used to control vacuum. A vacuum regulator maintains a constant vacuum at the regulator inlet with a higher vacuum connected to the outlet. During operation, a vacuum regulator remains closed until a vacuum decrease (a rise in absolute pressure) exceeds the spring setting and opens the valve disk. A vacuum breaker prevents a vacuum from exceeding a specified value. During operation, a vacuum breaker remains closed until an increase in vacuum (a decrease in absolute pressure) exceeds the spring setting and opens the valve disk. ReguRegulator

EDWIN SELVARAJ

BLANKETING GAS REGULATOR

EDWIN SELVARAJ

BLANKETING GAS REGULATORBlanketing is a process used to maintain a gas blanket in the vapor space of a pressure tight-liquid storage vessel. The gas blanketing regulator reduces a high pressure inert gas to maintain a positive low pressure of blanket gas over a stored liquid while liquid is being pumped out of the tank. A positive tank pressure prevents outside air from entering the vessel preventing contamination and reducing the possibility of atmospheric pressure collapsing the vessel.ReguReg

EDWIN SELVARAJ

Safety Relief ValveTOPICS

EDWIN SELVARAJ

Definitions of Safety/Relief ValvesSafety Valve is a direct-pressure actuated pressure relieving valve characterized by a pop action and suitable for Vapor or Gas applications (discharges to atmosphere)Relief Valve is a direct-pressure actuated pressure relieving valve with no pop action and usually with no definite blow-down or re-closure point. Used primarily for liquid service (discharges to drain)Safety-Relief Valve combination of the above (where would it discharge?)

EDWIN SELVARAJ

Typical Safety and Relief Valves

EDWIN SELVARAJ

Explain the Operating Principles of Safety ValvesSafety valves are held shut by means of a Steel spring or Torsion bar acting on the valve Disc so as to keep it on its SeatWhen the Boiler pressure reaches the pressure at which the valve is set (popping pressure), the disc will be raised slightly from its seat and steam will begin to escape through Ports or Holes and collect under the LipThe escaping steam provides an additional upward force and the valve then pops open

EDWIN SELVARAJ

Safety Valve Parts

EDWIN SELVARAJ

The Safety or Relief valve is a positive protection device which prevents the Boiler or other pressure vessels from exceeding that for which the vessel was designedThe ASME (American Society of Mechanical Engineers) Power Boilers code states that each boiler shall have at least one safety valve or safety relief valve and if the boiler has more than 47m2 of water heating surface, or if elec-tric, and it has a power input of more than 500 kw, then it shall have two or more safety valves or relief valves

EDWIN SELVARAJ

The 6% Rule:The safety valve must be able to discharge all of the steam produced by the Boiler without allowing the pressure to rise more than 6% above the highest pressure at which any valve is set and in no case more than 6% above the maximum allowable working pressure of the BoilerSafety Valve Capacity:The capacity of a particular design of safety valve is determined by means of tests which set the lift, popping and blow down pressures

EDWIN SELVARAJ

Safety/Relief Valve Types:1. Huddling Chamber Safety Valve:- Safety valves are held shut by means of a steel spring or torsion bar acting on the valve disc so as to keep it on its seat- When the Boiler pressure reaches the pressure at which the valve is set (popping pressure), the disc will be raised slightly from its seat and steam will begin to escape through Bleed holes- The escaping steam from the Bleed holes provides an additional upward force on the Lip of the disc and the valve then pops open

EDWIN SELVARAJ

Huddling Chamber Safety Valve

EDWIN SELVARAJ

2. Power - Operated Relief Valves:A Power-operated relief valve as defined by ASME, is one whose movements to open or close are fully controlled by a source of power (electricity, air/pneumatic, steam or hydraulic). The valve may be operated manually or automatically by remote control or deviceOn conventional type Boilers, this type cannot be used as a substitute for regular Safety or Relief valves, but can be used in conjunction with them (the next slide explains why)

EDWIN SELVARAJ

This type of Relief valve has a control station switch which has three positions:Automatic will open when preset high pressure setting is reached and re-seat itself closed when pressure has reduced to the preset low pressureManual - the valve opens regardless of pressureOff the relief valve will stay closed no matter what (this is why this type of relief valve cannot be used solely on the Boiler or any other pressure vessel)

EDWIN SELVARAJ

Installation and Operation of Safety Valves- A Safety valve or Relief valve must be connected to the Boiler independent of any other connection and attached as close to the Boiler as possible in an upright position with the spindle vertical- No valve of any type shall be placed between the Safety valve or Relief valve and the Boiler, or the discharge pipe of the Safety valve or Relief valve- The Safety/Relief valve discharge pipe shall not be smaller than the Safety/Relief valve outlet and the discharge pipe connection should be short and straight as possible

EDWIN SELVARAJ

- pressure on the Each valve must be equipped with gravity drains in the discharge pipe and the casing of the valve- To insure that the valve is not stuck in the closed position, each Safety/Relief valve shall have a lifting device or handle by which the valve disc can be lifted from its seat (there must be 75% of full working Boiler)

EDWIN SELVARAJ

Proper Safety Valve InstallationProper (left) and Incorrect (right) Installation

EDWIN SELVARAJ

Safety Valve Setting:The difference between the pressure at which the valve opens and the pressure at which the valve closes (by the spring tension), is called the BlowdownThe Blowdown, according to ASME section 1, PG-72.1, must be a minimum of 14 kPa, and the maximum Blowdown will allow the safety valve to close at a pressure not lower than 96% of the set pressure of the Safety valve* NOTE: Play Video of Safety Valves

EDWIN SELVARAJ

Safety Relief Valve-PartsPr Rel Valve

EDWIN SELVARAJ

ANALYTICAL INSTRUMENTSTOPICS

EDWIN SELVARAJ

Biochemical oxygen demand (BOD) What is Biochemical oxygen demand (BOD) ?BOD is an empirical analysis, that is performed in waste waters.This analysis determines the amount of oxygen expressed in PPM that micro-organisms consume from water when break down organic matter.BOD measures the rate of oxygen uptake by micro-organisms in a sample of water at a temperature of 20C.

Notes: Air can be regarded as having constant percentage of O2. Wherever air comes in contact with water, the oxygen in the air will dissolve in the water. The amount of oxygen that dissolves depends on-the water temperature, the air pressure and the salt contents of water.

EDWIN SELVARAJ

Introduction of pH-pH is a unit of measure which describes the degree of acidity or alkalinity of a solution. It is measured on a scale of 0-14. The term pH is derived from p, the mathematical symbol of the negative logarithm, and H the chemical symbol of Hydrogen. The formal definitionof pH is the negative logarithm of the Hydrogen ion activity.

EDWIN SELVARAJ

pH

EDWIN SELVARAJ

pH

EDWIN SELVARAJ

pH ElectrodesA pH having two electrode;- an measuring electrode and a reference electrode. Most applications today use a combination electrode with both electrode in one body. When the two electrodes are immersed in a solution a galvanic cell is established. The response of measuring electrode is the voltage developed between the inside and outside of the membrane. This voltage is proportional to the difference in pH in the inner solution and the sample. pH = -log[H+]

ANALYZER

EDWIN SELVARAJ

pH

EDWIN SELVARAJ

pH

EDWIN SELVARAJ

pH

EDWIN SELVARAJ

pH

EDWIN SELVARAJ

pH

EDWIN SELVARAJ

pH

EDWIN SELVARAJ

pH

EDWIN SELVARAJ

pH

EDWIN SELVARAJ

pH

EDWIN SELVARAJ

pH

EDWIN SELVARAJ

pH

EDWIN SELVARAJ

Conductivity Measurement

EDWIN SELVARAJ

ANALYZER-CONDUCTIVITYConductivity is the ability of a solution to conduct electric current.The principle by which instruments measures conductivity is simple - two plates (cells) are placed in the sample, a potential is applied across the plates and the current is measured.Generally, the potential is in the form of a sine wave.ANALYZER

EDWIN SELVARAJ

HPW4DefinitionsConductivity requires the presence of charged particles (ions) in solution, to carry the electrical current

The conductivity measurement uses an AC signal so that the ions do not polarize to the measuring plates.(Ex.: Sodium & Chloride ions)++AC++++

EDWIN SELVARAJ

ACHPW3Conductivity:DefinitionsProperty of a solution that represents the ability to conduct electricityResistivity:Reciprocal of Conductivity Resistivity = 1/Conductivity

EDWIN SELVARAJ

Definitions

Something has to be in the solution that carries the current and completes the circuit to have Conductivity.The something is positively and negatively charged atoms, called ions. Sodium (+) and Chloride (-) are typical examples of ions.For the Conductivity measurement, the instrument outputs an alternating square-wave signal on the DRIVE electrode of the sensor. The sensors RECEIVE electrode will pick-up the signal that is carried through the solution, by the ions.If a lot of free ions are available to get the majority of the signal from the drive to the receive electrode, then the solution is conductive and the Conductivity reading is high.If there are very few ions in solution, then little of the signal will reach the receive electrode and the Conductivity reading will be low.

EDWIN SELVARAJ

Conductivity

EDWIN SELVARAJ

Typical Conductivity Valuesohms-cmUltra purewaterDistilledWaterRawWater0.05%NaClSeaWater30%H2SO4Microsiemens/cmConductivity RangeResistivity RangeRange of Measurement Pure Water, 0.055 uS/cm (18.3 Meg ohms) Concentrated Acids, Bases and Salts, > 1,000,000 uS/cmTechnologies Available Electrode Inductive (also known as Electrodeless and Toroidal)

EDWIN SELVARAJ

Conductivity MeasurementsConductivity responds to all electrolytes in solutionConductivity can be used to measure the concentration of a particular electrolyte in a pure solutionConductivity can help determine the concentration of the dominant electrolyte in the presence of other electrolytesTypical uses for Conductivity AnalyzersGeneral Concentration Measurement and Control.Control Dilution of Pure Solutions and Mixtures.Leak DetectionInterface DetectionWater Quality

EDWIN SELVARAJ

Conductivity MeasurementsConductivity, unlike pH, is a non-specific measurement because it responds to any and all electrolytes in a solution. Nonetheless, it can be used to measure the concentration of a specific electrolyte under certain conditions:There must be a measurable change in conductivity over the concentration range to be measured. While conductivity can alternately increase and decrease with increasing concentration in strong solutions, concentrations measurements can only be made in ranges, where conductivity strictly increases or decreases.In addition to specific concentration measurements, conductivity can be used for the monitoring and control of dilutions, the detection of a leak of a more conductive solution into a less conductive solution.

EDWIN SELVARAJ

HPW6Cell ConstantCell Constant:Basic 1.0/cm Cell Constant:1.0 cm = 1.01.0cm2 cmACdddd = 1 centimeterDefined as the ratio of the distance separated, over the area of the platesDetermines how much signal is received by the analyzer for a solutions given conductivity

EDWIN SELVARAJ

Cell ConstantWhat are the mysteries behind this important term?First of all, Cell Constants have very funny units attached to them per cm. Once you realize that a cell constant is the ratio of how far the sensor electrodes are separated, divided by the area of the electrode plates, then the per cm units make some sense.Cell Constants are an area of confusion for many people.Not all cell constants can be calculated this easy, due to the complex geometry of some electrodes. It is typical in hi-purity measurements for the electrodes to be in the form of concentric cylinders, as compared to flat plates.The function of the cell constant is to optimize how much input signal is being provided to the analyzer for a solutions given conductivity.Matching the proper cell constant to the solutions conductivity range will ensure that the analyzer can properly condition and process the input signal.

EDWIN SELVARAJ

HPW7Cell Constant:Cell ConstantRelates the conductivity of the solution to the conductance read by the instrumentFactor used as a multiplier for the conductivity instrumentConductance MeterSolution Conductivity 10.00Cell Constant 2.0AC5.00

EDWIN SELVARAJ

Cell ConstantOlder conductivity instrumentation did not take the cell constant into account, and you would have to multiply the instrument reading by the cell constant to arrive at the conductivity of the solution. In this way, the cell constant is a multiplier for the conductivity instrument.Modern instrumentation can account for the cell constant and display the resultant conductivity reading of the solution. However, you still must be careful to match the appropriate cell constant with the analyzer.Some instruments are designed to work with only a specific cell constant. If a sensor with an improper cell constant is attached to the analyzer, then the readings will be erroneous. Some instruments can use various cell constants, but you must still program the instrument for the corresponding cell constant used. Finally, some advanced instrumentation uses smart sensors that tell the analyzer its cell constant and calibration factor.

EDWIN SELVARAJ

HPW8Cell ConstantCell Constants vary above and below 1.0/cm They optimize accuracy within a specific range Typically, the higher the Cell Constant; the higher the conductivity range0-10uS/cm Ultrapure Distillation50-500uS/cm Deionized Reverse Osmosis500-5000uS/cm Raw Water2-20mS/cm Chemical Control

EDWIN SELVARAJ

Cell Constant

Cell constants are used to maximize the accuracy of the conductivity reading in a specific range of measurement.Basically, the higher the cell constant, the higher the conductivity range to be measured.For high purity water in applications like Semiconductor, Power and Pharmaceuticals, it is important to use the lowest cell constant possible, which is 0.01/cm. Not all manufacturers make this range of cell, some stop at 0.1/cm. However, to maximize the accuracy at the ultrapure water range, the 0.01/cm cell constant is preferred.For applications where the water is not quite as pure (50-500uS/cm) such as, deionization trains and reverse osmosis skids, then the 0.1uS/cm cell constant is a good choice.For common conductivity ranges of raw waters and mixtures in the hundreds to the thousands of microsiemens, then the 1.0/cm cell constant should be used.Finally, for concentrated chemicals and brine solutions applications, it is important to use higher cell constants, such as 5-10/cm, or specialized sensors like 4-electrode or Toroidal sensors.

EDWIN SELVARAJ

Conductivity

EDWIN SELVARAJ

Conductivity

EDWIN SELVARAJ

Conductivity

EDWIN SELVARAJ

Conductivity

EDWIN SELVARAJ

Conductivity

EDWIN SELVARAJ

Model 400Sensor cylinder construction Geometric shapes differs but cell constant reminds true Operating Parameters:are cell constant dependantdesign dependantTemperature Compensation:Pt 1000 StandardOptional Pt-100 Process Connection3/4 inch MNPT

EDWIN SELVARAJ

ENDURANCE- Contacting SensorsConfigurations:Screw-In...Model 400/401Retractable...Model 402Sanitary...Model 403Low Flow Cell...Model 404Low Conductivity Measurement: Ultrapure to Surface Water Cell Constants of 0.01/cm, 0.1/cm and 1.0/cmHigh Conductivity Measurement:10.0 and 4 electrode (401)USE TOROIDAL IF POSSIBLE400401402403404

EDWIN SELVARAJ

Temperature Effects on ConductivityTemperature has drastic effects on conductivity measurements and is typically compensated forEach conductive solution has its own set of concentration vs temperature curvesTypical Temperature slopes (linear)Acids:1.0 to 1.6% / oCBases:1.8 to 2.2% / oCSalts:2.2 to 3.0% / oCNatural Waters:2.0% / oC0-5% / oC Temperature slope adjustment, in our instruments, provides greater accuracy in chemical concentration controlSpecific common temperature curves are programmed into specialized percent concentration analyzers for higher accuracy and ease of use for concentration measurementsLow conductivity measurements (less than 10 microSiemens/cm) require special temperature compensation for accuracy

EDWIN SELVARAJ

Temperature Slope for Low Conductivity Water 024681012141618202224260102030405060708090100TEMPERATURE DEGREE CTEMPERATURE SLOPE ( % PER DEG C )PURE WATER0.1 microS/cm1.0 microS/cm

EDWIN SELVARAJ

HPW12CATION Applications require an additional special temperature compensation algorithm Temperature CompensationCATION: Positively charged atomsResin BeadsH+-H+--H+--H+Na+--Mg+-Na+Na+Mg+FLOWCATION BedH+OH-H+OH-H+H+H+H+Feed WaterProduct WaterCATIONS displace Hydrogen Ions on the resin beads; causing Product Water to be more acidic

EDWIN SELVARAJ

HPW13Temperature CompensationCATION Water is moreacidic than equivalentHigh-Purity Water;therefore, it has adifferent temperaturebehaviorAll New Rosemount Instruments include CATION temperature compensationCation00.10.20.30.40.50.60.70.80.9CATION 0.1S/cm vs. High-Purity 0.1 S/cmHi- Purity0255075100Temperature C:conductivity (uS)

EDWIN SELVARAJ

Conductivity Analyzers and TransmittersContacting ConductivityElectrodes Exposed to the Measured SolutionAffected by Dirty or Corrosive Process StreamsInductive ConductivityNo Electrodes Exposed to the Measured SolutionRelatively Unaffected by Dirty or Corrosive Process Streams

EDWIN SELVARAJ

Principle of Operation Toroidal ConductivityElectrodes do not contact the process streamTwo toroidal wound coilsDrive coil is energized by > 20KzIn turn inducing an Alternating Current in to the liquidInduced current in the solution picked up by second coilInduced current in second coil is DIRECTLY proportional to the solution Conductivity

EDWIN SELVARAJ

Principle of Operation Toroidal Conductivity SensorDrive CoilPick-up CoilInput Voltage to CoilInduced Current dependenton the Conductivity of theSampleSampleSample

EDWIN SELVARAJ

Toroidal Sensors

EDWIN SELVARAJ

Toroidal Sensors

EDWIN SELVARAJ

Model 228 Toroidal SensorCommon ApplicationsHigh ConductivitySuspended Solids Content% ConcentrationOperating Parametersdesigned for coating application Harsh environmentsRecommended Measurement Ranges:250 uS/cm - 2,000,000 uS/cm*Dependent on Instrument Selection

EDWIN SELVARAJ

Toroidal Sensors create a magnetic flux around A Toroidal sensor creates a magnetic flux around the sensor about the size of a base ball (cricket ball)

EDWIN SELVARAJ

Toroidal Sensor simulationDue the nature of Toroidal measurement it is difficult to simulate an input directly into the analyzer.

The best thing to do is to test the entire loop (sensor and transmitter). To simulate an input place a resistance through the Toroidal sensor, calculate the reading using the formulas, and verifying the actual reading matches the calculated reading. Use more then one resistance to confirm the loop works correctly

If it does not work, perform a continuity test on each of the coils. If the continuity test fails, cut about 30 millimeters off the back end of the cable and retest. If the continuity test passes, then replace the sensor with a known good sensor and retest with resistors.

EDWIN SELVARAJ

Check coil continuityIf the loop does not react to a resistance through the Toroidal sensor remove the sensor from the analyzer and check for continuity of the drive (2 ohms) and receive (2 ohms) coils. Make sure there is no continuity between the two coils.2.0ohmsIf the coils are open cut off about 10 millimeters of cable and re-check for continuity. Continue to cut cable until continuity is established. Re-terminate and rewire sensor to the analyzer and check calibration with resistors.Topics

EDWIN SELVARAJ

Solution simulation10.0 mS/cmA Toroidal signal can not be simulated directly into the analyzer with resistors. A loop check must be performed where the Toroidal sensor and analyzer are wired together and a closed resistance is threaded through the Toroidal sensors hole. Nominal cell constant is 3.0

EDWIN SELVARAJ

ENDURANCE - Model 404 Low Flow CellCommon ApplicationsApplications Where Low Flow Rates Are Present, Typically Ultra Pure WaterAvailable in Two Cell Constants For Use Up To 2000 uS/cm.01 uS/cm0.1 uS/cmMaterial of construction Hot temp use SST for cooler processes use PVC Sensor must be calibrated with flow cell because outer electrode is built into the walls of the flow cel

EDWIN SELVARAJ

Conductivity measurement is comprised of these distinct components. The sensor A connecting cable (may be a VP connector)An analyzer or transmitter Power sourceTroubleshooting a Conductivity loopThe Process

EDWIN SELVARAJ

How Conductivity measurement is madeThe conductivity sensor does not make an electro-chemical reaction like pH and amperometric sensors do, but acts as a deliverer and receiver of a square wave signal generated at the analyzer.

EDWIN SELVARAJ

The conductivity sensor does not make an electro-chemical reaction like pH and amperometric sensors do, but acts as a deliverer and receiver of a square wave signal generated at the analyzer. How Conductivity measurement is madeThe amplitude of the returning square wave signal is processed with the temperature signal in the analyzer, and the conductivity of the solution is displayed locally. 218 uS/cm

EDWIN SELVARAJ

Isolation stepsIsolation of the problem can be done in 4 steps

1st, remove the sensor from the process and place it in a known solution This eliminates any process-related interference Ground Loops Verifies the loop is working correctly

2nd, remove the sensor and simulate an input Verifies that the analyzer is working correctly

3rd, remove the analyzer from its mounted position this eliminates ground loops caused by faulty wiring and poor earth grounding

4th, remove the analyzer from the factory floor and place on a bench this verifies possible power related issues it also points to possible communication problems

EDWIN SELVARAJ

Substituting a sensors signalIf the source of problem is not process related

simulate an input in to analyzer

simulating an input signal confirms analyzer status

determine signal needed

use ohms law to predict input signal

EDWIN SELVARAJ

Clarity II TurbidimeterANALYZER

EDWIN SELVARAJ

What is Turbidity?DefinitionExpression of the optical property that causes light to be scattered and absorbed rather than transmitted in straight lines through the sample.The relative clearness of water.ExplanationNot a direct measure of suspended solids in water, but a determination of the scattering effect such solids have on light.Color has an adverse effect on reading.Bubbles effect reading.A sudden change in turbidity could indicate a change in your process.MeasurementUnit of Measurement: Nephelometric Turbidity Units (NTU).

EDWIN SELVARAJ

THEORY-TURBIDIMETERDuring the early 1900s, the first instrument to make a turbidity measurement was referred to as the Jack Candle Turbidimeter, and consisted of a candle and a glass tube calibrated to equivalent ppm suspended silica turbidity.In the 1930s, a white light bulb and a photo detector was used to monitor the intensity of light scattered at 90.Turbidity is the measure of the amount of light scattered by particles in a sample. A beam of light passes through a sample containing suspended particles. The particles interact with the light and scatter the light. A detector measures the intensity of the scattered light.

EDWIN SELVARAJ

Turbidity vs. Total Suspended SolidsTurbidity is not the same as total suspended solids (TSS). Both turbidity and TSS are defined by the method used to measure them.TSS is a gravimetric measurement; it depends on the total mass of filterable material in the sample.Turbidity is an optical measurement; it depends on the number of particles in the sample and their shape and size.100 mg of solidparticles in 1 LTSS is 100 mg/L.Turbidity hasa certain value100 mg of solidparticles in 1 LTSS is 100 mg/L.Turbidity is different: moreparticles andsmaller size.Cut each particle in half

EDWIN SELVARAJ

Clarity II Online Turbidimeter System

EDWIN SELVARAJ

Turbidity Theory - Basic NephelometerTurbidity is the measure of the amount of light scattered by particles in a sample. A beam of light passes through a sample containing suspended particles. The particles interact with the light and scatter the light. A detector at 90 measures the intensity of the scattered light.

EDWIN SELVARAJ

Clarity II Online TurbidimeterClarity II enhancements: Pre-mounted Clarity II turbidity loop on a panel High pressure, flow-through chamber - Special Custom Dry Cal standard: AMCO clear polymer beads Sensor and chamber improvements as needed

EDWIN SELVARAJ

Installation: Plug and PlumbPlug and Plumb System: Pre-mounted analyzer, sensor(s) and debubbler/measuring chamber mounted on an ABS back plate.Dry Check CupMolded Debubbler and Measuring ChamberAnalyzerQuick Disconnect CableCalibration Cup

EDWIN SELVARAJ

Light SourceDetectorParticlesSensor Operation: Light Source and Detector

EDWIN SELVARAJ

Online TurbidimeterHow is the Clarity II turbidity measurement made?A detailed animation of the sensor optics shows a light source beam (blue color), particles floating around in the liquid medium inside the measuring chamber, and the detector (red color).The beam of light passes through the sample containing particles. The particles interact with the light and scatter the light. The detector measures the intensity of the scattered light.

EDWIN SELVARAJ

FoulingSuspended matter in the sample coats the photodiode window.The coating blocks the light, so less light falls on the photodiode. Less light falling on the photodiode means a lower apparent turbidity reading.photodiodeturbidityturbidity

EDWIN SELVARAJ

Lamp agingAs lamp ages, light intensity decreases. Therefore, the amount of scattered light decreases even though number of particles remains constant.

EDWIN SELVARAJ

Lamp diagnosticsIntensitydetectorVoltage FeedbackCurrentregulatorLight Power Source

EDWIN SELVARAJ

Lamp diagnosticsLight SourceIntensitydetectorVoltage FeedbackCurrentregulatorLight Power SourceEPA = LampLamp feed back voltage must be between1200mV and 1600mV

Lamp mid range voltage1400mV +/- 200mV

Maximum current 370mA

Weak Lamp voltage (replace the lamp)Less then 1250mV

ISO = LEDLED feedback voltage2000mV +/- 200mV

Target current10mA

A light intensity detector built into lamp board automatically increases the current to the lamp keeping the light intensity within specs. If the detected lamp intensity is below specifications that analyzer will blink Lamp calibration needed. ANALYZER

EDWIN SELVARAJ

Analyzer-MoistureMoisture analyzer used to measure moisture contents in a process gas.In the operating mode sensor isalternately exposed to the samplegas and dry reference gas. A dryreference gas is produced bypassing portion of the sample gas through the dryer to remove any moisture present.The difference in resonant frequencyof the sensor, as measured whenexposed to each of the two gasstreams, is a function of moisturecontent of the sample gas.Thus, the moisture concentration ofthe sample gas is determined fromthis frequency.ANALYZER

EDWIN SELVARAJ

Analyzer-O2-Zirconia

EDWIN SELVARAJ

Analyzer-O2-ZirconiaAnal

EDWIN SELVARAJ

FIRE & GAS DETECTOR1.GAS2.HEATTOPICS

EDWIN SELVARAJ

Detector-GasGas sensors interact with a gas to initiate the measurement of its concentration. The gas sensor then provides output to a gas instrument to display the measurements.Important measurement specifications to consider when looking for gas sensors include the response time, the distance, and the flow rate. The response time is the amount of time required from the initial contact with the gas to the sensors processing of the signal. Distance is the maximum distance from the leak or gas source that the sensor can detect gases. The flow rate is the necessary flow rate of air or gas across the gas sensor to produce a signal

EDWIN SELVARAJ

EDWIN SELVARAJ

EDWIN SELVARAJ

EDWIN SELVARAJ

ELECTROCHMICAL CELL APPLICATIONS-Electrochemical Sensor consisting of a sensing electrode a counter electrode and a reference electrode seperated by an electrolyte reservoir. Gas contacting the sensor diffuses through a capillary diffusion barrier which controls the amount of gas entering the sensor. A gas permeable membrane reacts at the surface of the sensing electrode by either oxidation or reduction.

EDWIN SELVARAJ

MDS SENSING APPLICATIONS-The MOS film deposited onto a substrate between two electrodes. With no gas present, the resistance between the two electrodes is very high. As gas comes into contact with the sensor the resistance decreases (to kilo-ohms). The decrease in resistance is proporational to the concentration of gas present.

EDWIN SELVARAJ

INFRARED SENSING APPLICATIONS-In fixed point detectors there is a fixed path length between IR Source & IR Detector. Typically the path length is very short-(few inches) and the gas concentration is assumed to be uniform across the path. With a fixed path length, the measurement of absorption of the IR beam by the gas being measured can be expressed directly as PPM.

DETECTOR

EDWIN SELVARAJ

HEAT DETECTORHEAT DETECTOR is a device that responds to changes in ambient temperature. When temperature rises above the set point, it used as an alarm device to alert personnel or used as release device, to sense fire and actuate fire attack systems. HEAT DETECTORS are classified into two types:-1.Rat-of-Rise Detector 2.Fixed Temperature DetectorRat-of-Rise Detector react the sudden change or rise in ambient temperature from a normal baseline condition.Fixed Temperature Detector reacts when the ambient temperature reaches fixed pointF & G

EDWIN SELVARAJ

INSTRUMENT LOOPSTOPICS

EDWIN SELVARAJ

INSTRUMENT SYMBOLS

EDWIN SELVARAJ

INSTRUMENT SYMBOLS

EDWIN SELVARAJ

INSTRUMENT SYMBOLS

EDWIN SELVARAJ

INSTRUMENT SYMBOLS

EDWIN SELVARAJ

INSTRUMENT SYMBOLSTOPICS

EDWIN SELVARAJ

International Electrical Commission (IEC)

National Electrical Code (NEC)

National Electrical Manufacturers Association (NEMA)

American National Standard Institute, Inc. (ANSI)

Instrument Society of America (ISA)

Institute of Electrical and Electronic Engineers (IEEE)

International Standards Organization (ISO)

American Petroleum Institute (API)

API RP550: Installation of Refinery Instruments And Controls Systems

10. API Standard 670:Vibration, Axial-Position and Bearing Temperature Monitoring systems11. Offshore Reliablity Data (OREDA) changed as ISO 14224

CODES & STANDARDSCODECODECODE

EDWIN SELVARAJ

Definitions of Safety/Relief ValvesSafety Valve is a direct-pressure actuated pressure relieving valve characterized by a pop action and suitable for Vapor or Gas applications (discharges to atmosphere)Relief Valve is a direct-pressure actuated pressure relieving valve with no pop action and usually with no definite blow-down or re-closure point. Used primarily for liquid service (discharges to drain)Safety-Relief Valve combination of the above (where would it discharge?)

EDWIN SELVARAJ

Typical Safety and Relief Valves

EDWIN SELVARAJ

Explain the Operating Principles of Safety ValvesSafety valves are held shut by means of a Steel spring or Torsion bar acting on the valve Disc so as to keep it on its SeatWhen the Boiler pressure reaches the pressure at which the valve is set (popping pressure), the disc will be raised slightly from its seat and steam will begin to escape through Ports or Holes and collect under the LipThe escaping steam provides an additional upward force and the valve then pops open

EDWIN SELVARAJ

Safety Valve Parts

EDWIN SELVARAJ

The Safety or Relief valve is a positive protection device which prevents the Boiler or other pressure vessels from exceeding that for which the vessel was designedThe ASME (American Society of Mechanical Engineers) Power Boilers code states that each boiler shall have at least one safety valve or safety relief valve and if the boiler has more than 47m2 of water heating surface, or if elec-tric, and it has a power input of more than 500 kw, then it shall have two or more safety valves or relief valves

EDWIN SELVARAJ

The 6% Rule:The safety valve must be able to discharge all of the steam produced by the Boiler without allowing the pressure to rise more than 6% above the highest pressure at which any valve is set and in no case more than 6% above the maximum allowable working pressure of the BoilerSafety Valve Capacity:The capacity of a particular design of safety valve is determined by means of tests which set the lift, popping and blow down pressures

EDWIN SELVARAJ

Safety/Relief Valve Types:1. Huddling Chamber Safety Valve:- Safety valves are held shut by means of a steel spring or torsion bar acting on the valve disc so as to keep it on its seat- When the Boiler pressure reaches the pressure at which the valve is set (popping pressure), the disc will be raised slightly from its seat and steam will begin to escape through Bleed holes- The escaping steam from the Bleed holes provides an additional upward force on the Lip of the disc and the valve then pops open

EDWIN SELVARAJ

Huddling Chamber Safety Valve

EDWIN SELVARAJ

2. Power - Operated Relief Valves:A Power-operated relief valve as defined by ASME, is one whose movements to open or close are fully controlled by a source of power (electricity, air/pneumatic, steam or hydraulic). The valve may be operated manually or automatically by remote control or deviceOn conventional type Boilers, this type cannot be used as a substitute for regular Safety or Relief valves, but can be used in conjunction with them (the next slide explains why)

EDWIN SELVARAJ

This type of Relief valve has a control station switch which has three positions:Automatic will open when preset high pressure setting is reached and re-seat itself closed when pressure has reduced to the preset low pressureManual - the valve opens regardless of pressureOff the relief valve will stay closed no matter what (this is why this type of relief valve cannot be used solely on the Boiler or any other pressure vessel)

EDWIN SELVARAJ

Installation and Operation of Safety Valves- A Safety valve or Relief valve must be connected to the Boiler independent of any other connection and attached as close to the Boiler as possible in an upright position with the spindle vertical- No valve of any type shall be placed between the Safety valve or Relief valve and the Boiler, or the discharge pipe of the Safety valve or Relief valve- The Safety/Relief valve discharge pipe shall not be smaller than the Safety/Relief valve outlet and the discharge pipe connection should be short and straight as possible

EDWIN SELVARAJ

- pressure on the Each valve must be equipped with gravity drains in the discharge pipe and the casing of the valve- To insure that the valve is not stuck in the closed position, each Safety/Relief valve shall have a lifting device or handle by which the valve disc can be lifted from its seat (there must be 75% of full working Boiler)

EDWIN SELVARAJ

Proper Safety Valve InstallationProper (left) and Incorrect (right) Installation

EDWIN SELVARAJ

Safety Valve Setting:The difference between the pressure at which the valve opens and the pressure at which the valve closes (by the spring tension), is called the BlowdownThe Blowdown, according to ASME section 1, PG-72.1, must be a minimum of 14 kPa, and the maximum Blowdown will allow the safety valve to close at a pressure not lower than 96% of the set pressure of the Safety valve* NOTE: Play Video of Safety Valves

EDWIN SELVARAJ

SURGECompressor surge is an unstable phenomenon where the gas flow forward and backward across the machine alternatively. This phenomenon occurs at certain conditions of flow, pressure ratio and rotational speed.As a consequence some damages can o