Chapters 1-4 Flashcards
The first consideration of a process technician is
safety of employees and community
To be a good troubleshooter, you have to know ___
what is normal
Purpose of process instrumentation
to control PV at a desired SP
5 instruments of a control loop
sensor, transmitter, controller, final control element, transducer
Common flow elements
flow orifices, turbines, and other DP elements
Pressure
force per unit area (psi)
Atmospheric pressure at sea level
14.7 PSIA
Gauge pressure at sea level
0 PSIG
Level elements
dP cell, displacer (buoyancy), sight glass, float/tape, bubbler
wires of dissimilar metals connect at one end and generate electrical signal
Thermocouples
measures temperature based on electrical resistance
RTD (resistance temperature device)
BFD
Block Flow Diagram
PFD
Process Flow Diagram
P&ID
Piping and Instrument Diagram
Bubble with no line
field mounted
Bubble with solid line
control room mounted
What pressure are many large storage tanks designed to operate at?
atmospheric pressure
Most electric motors in industry are __ phase and run at ____ Volts
Most electric motors in industry are 3 phase and run at 480 Volts
Primary method of cooling in cooling tower
evaporative
Water tube boilers consist of a _______ drum (top), _____ tubes, and a _____ drum.
Water tube boilers consist of a STEAM drum (top), BOILER tubes, and a MUD drum (bottom)
A fired heater used to heat raw materials to operating temperature
Furnace
Type of heat exchanger that proves heat balance to a distillation column
Kettle Reboiler
Converts raw materials into useful products by chemical reaction
Reactor
What is used in a reactor to speed up the rate of reaction?
Catalyst
Separating components of a feed based on boiling points
Distillation
Distillation Column: Where do lighter products (low boiling point) exit the column and in what phase?
top in vapor phase
Distillation Column: Where do heavier products (high boiling point) exit the column and in what phase?
Bottom in liquid phase
Vapors from top of distillation are condensed in overhead condenser and collected in an ______
accumulator
A collection of instruments that work together to control a process variable (PV)
Control Loop
Typically designed to measure flow rate and control the flow downstream of the measuring device.
Flow Control Loop
Most common element in flow control loop
Orifice Plate
Creates a differential pressure (dP) that is measured by a transmitter
Orifice Plate
Composed of a tapered tube, scale, and a ball or float - usually a field instrument.
Rotameter
Pressure element that expands with increased pressure and collapses with lower pressure.
Bellows
Most common type of field pressure gauge. C-shaped element swells with increased pressure and moves a linkage that drives an indicator.
Bourdon tube
Senses pressure and sends signal to a controller or recorder
Pressure transmitter
How is temperature most often controlled?
By controlling the flow of a heating or cooling liquid
Most common temperature elements:
RTD and Thermocouple
Analytical instrument used to determine acidic or base
pH
Analytical instrument for suspended solids
Turbidity
Analytical instrument for dissolved solids
Conductivity
Controller located in the field or near equipment
Local Controller
Controller located in control room or on DCS
Remote Controller
PLC
Programmable Logic Controller
DCS
Distributed Control System
Converts one form of energy into another.
Transducer
Control Valve - FO
Fails Open (air to close)
Control Valve - FC
Fails Close (air to open)
Controller Mode used as a scaling factor from 0-100% output. Sometimes expressed as gain.
Proportional Band
Controller Mode - how large is the error and ow long did it last. Sometimes expressed as reset.
Integral
Controller Mode - how fast did the PV move away from the setpoint. Sometimes expressed as rate.
Derivative
Device designed to prevent damage to equipment and personnel.
Interlock
Controls conditions that must be satisfied before a piece of equipment can be started
Permissive
