Process diagrams book


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A brief out of all the technical symbols used in any instrumentation prject

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Process diagrams book

  1. 1. 30678_12_ch12_p251-270.qxd 06/09/2006 11:14 Page 251 MASTER ➁ Process Diagrams OBJECTIVES After studying this chapter, the student will be able to: • Review process diagram symbols. • Describe the use of process diagrams and the information they contain. • Draw a process flow diagram. • Draw a process and instrument drawing. • Describe the various process equipment relationships. 251
  2. 2. 30678_12_ch12_p251-270.qxd 06/09/2006 11:14 Page 252 MASTER ➁ Chapter 12 ● Process Diagrams Key Terms Electrical drawings—symbols and diagrams that depict an electrical process. Elevation drawings—a graphical representation that shows the location of process equipment in relation to existing structures and ground level. Equipment location drawings—show the exact floor plan for location of equipment in relation to the plan’s physical boundaries. Flow diagram—a simplified sketch that uses symbols to identify instruments and vessels and to describe the primary flow path through a unit. Foundation drawings—concrete, wire mesh, and steel specifications that identify width, depth, and thickness of footings, support beams, and foundation. Legends—a document used to define symbols, abbreviations, prefixes, and specialized equipment. Process and instrument drawing (P&ID)—a complex diagram that uses process symbols to describe a process unit; also called piping and instrumentation drawing. Types of Process Diagrams Process diagrams can be broken down into two major categories: process flow diagrams (PFDs) and process and instrument drawings (P&IDs), sometimes called piping and instrumentation drawings. A flow diagram is a simple illustration that uses process symbols to describe the primary flow path through a unit. A process flow diagram provides a quick snapshot of the operating unit. Flow diagrams include all primary equipment and flows. A technician can use this document to trace the primary flow of chemicals through the unit. Secondary or minor flows are not included. Complex con- trol loops and instrumentation are not included. The flow diagram is used for visitor information and new employee training. A process and instrument drawing is more complex. The P&ID includes a graphic representation of the equipment, piping, and instrumentation. Mod- ern process control can be clearly inserted into the drawing to provide a process technician with a complete picture of electronic and instrument systems. Process operators can look at their process and see how the en- gineering department has automated the unit. Pressure, temperature, flow, and level control loops are all included on the unit P&ID. Basic Instrument Symbols Process technicians use P&IDs to identify all of the equipment, instru- ments, and piping found in their units. New technicians use these drawings 252
  3. 3. 30678_12_ch12_p251-270.qxd 06/09/2006 11:14 Page 253 MASTER ➁ Basic Instrument Symbols VALVES S H Gate Needle Four-Way Angle Diaphragm Manual Valve Solenoid Hydraulic Back Back Operated Gauge Pneumatic Valve Valve Pressure Operated Pressure CLOSED Regulator Regulator Globe Three-Way Valve Butterfly Valve M Pneumatic Operated Relief Ball Plug Bleeder Butterfly Valve Safety Check Valve Orifice Motor Rotameter PRV Valves PSV COMPRESSORS PUMPS & TURBINE Vacuum Reciprocating Compressor & Centrifugal Centrifugal Pump Compressor Silencers Compressor Pumps Vertical T Screw Pump Rotary Liquid Ring Centrifugal Compressor Gear Pump Turbine Compressor Compressor (Turbine Driven) HEAT EXCHANGERS LINE SYMBOLS Future Equipment Major Process Hairpin Exchanger U-Tube Shell & Tube Heat Exchanger Minor Process Heat Exchanger Pneumatic Hydraulic L L L Capillary Tubing X X XXX Single Pass X Electromagnetic Signal Heat Exchanger Reboiler Heater Condenser Electric VESSELS TI Temp Indicator Drum or Condenser TT Temp Transmitter TR Temp Recorder Mixer LI Level Indicator LT Level Transmitter Tank LC Level Controller Mixing Reactor Forced-Draft Cooling Tower FI Flow Indicator FT Flow Transmitter FR Flow Recorder PI Pressure Indicator Tower Tower PT Pressure Transmitter Bin with Packing PRC Pressure Recording Furnace Induced-Draft Cooling Tower Controller Figure 12.1a Process and Instrument Symbols 253
  4. 4. 30678_12_ch12_p251-270.qxd 06/09/2006 11:14 Page 254 MASTER ➁ Chapter 12 ● Process Diagrams TI Temp Indicator FI Flow Indicator I Transducer P TT Temp Transmitter Flow Transmitter PIC Pressure Indicating FT 105 Controller TR Temp Recorder FR Flow Recorder PRC Pressure Recording 40 Controller TC Temp Controller FC Flow Controller LA Level Alarm 25 LI Level Indicator PI Pressure Indicator FE Flow Element LT PT Level Transmitter Pressure Transmitter TE Temperature Element 65 55 LR Level Recorder PR Pressure Recorder LG Level Gauge 65 55 LC Level Controller PC Pressure Controller AT Analyzer Transmitter 65 55 Variable Being What It Does Measured Instrument FIC 55 Field Mounted Remote Location Remote Location Control Loop (board mounted) (behind control panel) Figure 12.1b Process and Instrument Symbols (continued) during their initial training period. Knowing and recognizing these symbols is important for a new technician. The chemical processing industry has as- signed a symbol for each type of valve, pump, compressor, steam turbine, heat exchanger, cooling tower, basic instrumentation, reactor, distillation column, furnace, and boiler (Figure 12.1). There are symbols to represent major and minor process lines and pneumatic, hydraulic, or electric lines, and there is a wide variety of electrical symbols. Flow Diagrams New technicians are required to study a simple flow diagram of their as- signed operating system. Process flow diagrams typically include the major equipment and piping path the process takes through the unit. As operators learn more about symbols and diagrams, they graduate to the much more complex P&IDs. 254
  5. 5. 30678_12_ch12_p251-270.qxd 06/09/2006 11:14 Page 255 MASTER ➁ Flow Diagrams Cooling Tower Vacuum Pump Product Tank 1 Drum Furnace Feed Tank Column Product Tank Reactors 2 Bottoms Tank Boiler Figure 12.2 Process Flow Diagram (PFD) Some symbols are common among plants; others differ from plant to plant. Some standardization of process symbols and diagrams is taking place. The symbols used in this chapter reflect a wide variety of petrochemical and refinery operations. Figure 12.2 is a PFD that shows the basic relationships and flow paths found in a process unit. It is easier to understand a simple flow diagram if it is broken down into sections: feed, preheating, the process, and the final products. This simple left-to-right approach allows a technician to identify where the process starts and where it will eventually end. The feed section includes the feed tanks, mixers, piping, and valves. In the second step, the process flow is gradually heated for processing. This section includes heat exchangers and furnaces. In the third section, the process is included. Typ- ical examples found in the process section could include distillation columns or reactors. The process area is a complex collection of equipment that works together to produce products that will be sent to the final section. 255
  6. 6. 30678_12_ch12_p251-270.qxd 06/09/2006 11:14 Page 256 MASTER ➁ Chapter 12 ● Process Diagrams Process and Instrument Drawings A P&ID is a complex representation of the various units found in a plant (Figure 12.3). It is used by people in a variety of crafts. The primary users of the document after plant startup are process technicians and instrument and electrical, mechanical, safety, and engineering personnel. In order to read a P&ID, the technician needs an understanding of the equipment, instrumentation, and technology. The next step in using a P&ID is to memorize your plant’s process symbol list. This information can be found on the process legend. Process and instrument drawings have a va- riety of elements, including flow diagrams, equipment locations, elevation plans, electrical layouts, loop diagrams, title blocks and legends, and foun- dation drawings. The entire P&ID provides a three-dimensional look at the various operating units in a plant. Process Legend The process legend (Figure 12.4) provides the information needed to inter- pret and read the P&ID. Process legends are found at the front of the P&ID. The legend includes information about piping, instrument and equipment P-12 CT-105 P-13 V-2 V-3 PC I/P PT PCV D-105 LT LC I/P P-14 Tk-12 F-105 Tk-10 V-4 C-105 V-5 Rx-105 FC I/P V-6 FT TT TC Tk-14 V-1 TE TT TC I/P LT FCV I/P Rx-106 P-10 LC P-15 I/P EX-105 Tk-16 V-7 B-105 P-11 Figure 12.3 Process and Instrument Diagram (P&ID) 256
  7. 7. 30678_12_ch12_p251-270.qxd 06/09/2006 11:14 Page 257 MASTER ➁ Process and Instrument Drawings VALVE SYMBOLS EQUIPMENT CONT. LINE SYMBOLS Future Equipment Ball Gate Pneumatic Manual Major Process Bleeder Valve Operated Valves Valve Minor Process Plug Pneumatic Angle Pneumatic Globe Knife Valve Hydraulic L L L Valve INDUCED DRAFT Butterfly Crossflow Capillary Tubing X X X X S Relief Pinch Valve Valve Mechanical Link • • • • Solenoid Valve SAFETY (Gases) CLOSED Check Stop Check Electromagnetic, Sonic Valve Optical, Nuclear Diaphragm Three-Way Electric Four-Way Valve NATURAL DRAFT Connecting Line EQUIPMENT SYMBOLS Counterflow Non-Connecting Line Non-Connecting Line Jacketed or Double Containment Vacuum Horizontal Pump Software or Data Link Vertical INSTRUMENT SYMBOLS Sump Pump Orifice BOILER TI Temp. Indicator FI Flow Indicator Centrifugal Rotameter TT Temp. Transmitter FT Flow Transmitter Gear Pump TR Temp. Recorder Flow Recorder Positive Rotary Screw FR Displacement FURNACE Compressor TC Temp. Controller FC Flow Controller Gauge LI Level Indicator PI Pressure Indicator Reciprocating Single Pump Pass Demister LT Level Transmitter PT Pressure Transmitter 65 55 Screw Pump Spray Nozzle LR PR Chimney Level Recorder Pressure Recorder 65 55 Progressive Cavity Packed Two Pass Section LC Level Controller PC Pressure Controller 65 55 FE Flow Element I Transducer Draw Off P C C TE Temperature Element PIC Pressure Indicating Generic Controller Manway 105 Tray Double-Pipe Plate and Frame LG Level Gauge PRC Pressure Recording Spiral Heat 40 Controller Heat Exchanger Exchanger Heat Exchanger Vortex AT Analyzer Transmitter LA Level Alarm Breaker 25 P C Air Cooled Exchanger E (Louvers Optional) Drum APPROVED Sphere DATE 10-6-99 Dome Roof Tank GENERAL LEGEND Condenser DISTILLATION UNIT Cone Roof Internal Floating DRAWING NUMBER Tank Roof Tank OO6543 REVISION 1 PAGE 1 OF 30 Heater PREFIXES ABBREVIATIONS CW- cooling water RX- reactor D- drum TK-tank P- pump MU- makeup UT- utilities C- column F- furnace V- valve FW- feed water CA- chemical addition CT- cooling tower EX- exchanger SE- sewer IA- instrument air Figure 12.4 Process Legend 257
  8. 8. 30678_12_ch12_p251-270.qxd 06/09/2006 11:14 Page 258 MASTER ➁ Chapter 12 ● Process Diagrams S 4" E W 18" Remesh 12" N 2 x 64 x 18" Load-Bearing Rebar in Beam All Beams 32 0" Remesh Remesh Over Plastic 6-8-10 Method 6 0" 10 0" 28 0" 90 8 0" 28 0" 64 0" width x length x thickness Estimating Materials: cu. yds. = 27 Figure 12.5 Foundation symbols, abbreviations, unit name, drawing number, revision number, approvals, and company prefixes. Because symbol and diagram standard- ization is not complete, many companies use their own symbols in unit drawings. Unique and unusual equipment will also require a modified sym- bols file. Foundation Drawing The construction crew pouring the footers, beams, and foundation uses foundation drawings (Figure 12.5). Concrete and steel specifications are designed to support equipment, integrate underground piping, and provide support for exterior and interior walls. Process technicians do not typically use foundation drawings, but these drawings are useful when questions arise about piping that disappears under the ground and when new equip- ment is being added. Elevation Drawing Elevation drawings (Figure 12.6) show the location of process equipment in relation to existing structures and ground level. In a multistory structure, the elevation drawing provides the technician with information about 258
  9. 9. 30678_12_ch12_p251-270.qxd 06/09/2006 11:14 Page 259 MASTER ➁ Process and Instrument Drawings RX-300 TK-300 C-300 Figure 12.6 Elevation Drawing EL-40 0" D-56 EL28 0" RX-105 EL 16 0" TK-105 TK-200 RX-106 equipment location. This information is important for making rounds, check- ing equipment, developing checklists, catching samples, and performing startups and shutdowns. Electrical Drawing Electrical drawings (Figure 12.7) include symbols and diagrams that de- pict an electrical system. Electrical drawings show unit electricians where power transmission lines run and places where power is stepped down or up for operational purposes. A process technician typically traces power to the unit from a motor control center (MCC). The primary components of an electrical system are the MCC, motors, transformers, breakers, fuses, switchgears, starters, and switches. Specific safety rules are attached to the operation of electrical systems. The primary safety system is the isolation of hazardous energy “lock-out, tag-out.” Process technicians are required to have training in this area. Figure 12.7 shows the basic symbols and flow path associated with an electrical drawing. Electrical lines are typically run in cable trays to switches, motors, ammeters, substations, and control rooms. A transformer is a device used by industry to convert high voltage to low voltage. The electric department always handles problems with transform- ers. Electric breakers are designed to interrupt current flow if design condi- tions are exceeded. Breakers are not switches and should not be turned on 259
  10. 10. 30678_12_ch12_p251-270.qxd 06/09/2006 11:14 Page 260 MASTER ➁ Chapter 12 ● Process Diagrams 69,000 Volts 69 KV MAIN TRANSFORMER V A As 51 Vs 27 13,200 V 13.2 KV 13, 800 V 13.8 KV 2,300 V 2.3 KV Generator 480V BUS MAIN POWER DISTRIBUTION BOILER Steam MCC #1 2.3 KV or Turbine 480 Volts ELECTRIC POWER PLANT Motor Motor Starter Starter M M Motor On Off M Motor Fuse MCC Motor Control Center V Voltmeter: measures voltage Vs Voltmeter Switch 27 Under Voltage Relay Current Transformer: reduces high voltage to instrumentation. A Ammeter: measures electric current As Ammeter switch Transformer Overcurrent Relay Potential Transforming Symbol 50 (Instantaneous) Transformer Overcurrent Relay 51 Power Transformer: reduces high voltage (Time delay) Circuit Breaker: a protective device that interrupts current flow through an Switch Motor Circuit Contacts electric circuit Figure 12.7 Electrical Drawing 260
  11. 11. 30678_12_ch12_p251-270.qxd 06/09/2006 11:14 Page 261 MASTER ➁ Process and Instrument Drawings or off. If a tripping problem occurs, the technician should call for an electri- cian. Fuses are devices designed to protect equipment from excess cur- rent. A thin strip of metal will melt if design specifications are exceeded. During operational rounds, technicians check the ammeters inside the MCC for current flow to their electrical systems. Voltmeters, electrical devices used to monitor voltage in an electrical system, are also checked during routine rounds. Equipment Location Drawing Equipment location drawings (plot plans) show the exact location of equipment in relation to the plant’s physical boundaries (Figure 12.8). One of the most difficult concepts to explain to a new process technician is the scope and size of modern chemical processing. Most chemical plants and refineries closely resemble small cities; they have well-defined blocks and areas connected by a highway of piping and equipment. Equipment loca- tion drawings provide information about the neighborhood. Loop Diagrams A loop diagram traces all instrument connections between the field instru- ment and the control room panel. This includes instrument air lines, wiring connections at field junction boxes, and control room panels and front connections. Electrical One-Line Diagrams Like the piping in process systems, the wiring in a unit follows a path. Electri- cal diagrams show a flow path for distributing power throughout the unit and Figure 12.8 TK-1 TK-2 Equipment Location 8 0" TK-3 TK-4 P-100 20 0" 18 0" 8 0" 20 0" P-200 20 0" 6 0" TK-100 D-200 EX-200 TK-200 18 0" P-500A C-200 8 0" P-201 TK-300 EX-202 TK-400 20 0" 10 0" P-300 16 0" P-400 261
  12. 12. 30678_12_ch12_p251-270.qxd 06/09/2006 11:14 Page 262 MASTER ➁ Chapter 12 ● Process Diagrams to all electrical equipment. These diagrams show the different voltage levels in the unit, electrical equipment such as transformers, circuit breakers, fuses, and motors and horsepower required. It also includes start/stop switches, emergency circuits, and motor control centers. Process technicians can use these diagrams to trace a system from the power source to the load. Review of Basic and Specialized Symbols Piping and Valves Each plant will have a standardized file for their piping symbols. Process technicians should carefully review the piping symbols for major and minor flows; electric, pneumatic, capillary, and hydraulic elements; and future equipment (Figure 12.9). The major flow path through a unit illustrates the Figure 12.9 Removable Spool Piping Symbols Y-type Strainer RS Flexible Hose Duplex Strainer Expansion Joint Basket Strainer XXX Breather Vent Cover D Detonation Arrestor In-Line Mixer F Flame Arrestor S In-Line Silencer S Vent Silencer Diverter Valve T Steam Trap DS Desuperheater Rotary Valve Ejector / Eductor Pulsation Dampener Exhaust Head Flange Future Equipment Electromagnetic, Sonic Optical, Nuclear Major Process Electric Minor Process Connecting Line Pneumatic Non-Connecting Line LLL Hydraulic Non-Connecting Line X X X X Capillary Tubing Jacketed or Double Containment • • • • Mechanical Link Software or Data Link 262
  13. 13. 30678_12_ch12_p251-270.qxd 06/09/2006 11:14 Page 263 MASTER ➁ Review of Basic and Specialized Symbols critical areas a new technician should concentrate on. A variety of other symbols are included on the piping. These include valves (Figure 12.10), strainers, filters, flanges, spool pieces, insulation, piping size, pressure rat- ing, material codes, and steam traps. Pumps and Tanks Pumps and tanks come in a variety of designs and shapes. Common pump and tank symbols are shown on Figure 12.11. Compressors, Steam Turbines, and Motors Because compressors and pumps share a common set of operating prin- ciples and are classified as dynamic or positive displacement, the sym- bols for compressors may closely resemble those for pumps (compare GATE VALVES H Figure 12.10 M Valves Gate Manual Pneumatic Motor Hydraulic Bleeder Valve Operated Valves Valve GLOBE VALVES H M M Angle Globe Pneumatic Motor Hydraulic Needle Valve Pneumatic Motor BALL VALVES PLUG VALVES H M Ball Ball Motor or Plug Plug Motor or Hydraulic Hydraulic BUTTERFLY VALVES M S Butterfly Butterfly Butterfly Motor or Pneumatic Solenoid Valve Hydraulic Operated CLOSED DIAPHRAGM VALVES CHECK VALVES M Motor Check Check Stop Check Diaphragm Valve Valve SAFETY (Gases) RELIEF (Liquids) Three-Way Four-Way Valve Relief Valve Knife Valve Pinch Valve Gauge Rotameter Orifice 263
  14. 14. 30678_12_ch12_p251-270.qxd 06/09/2006 11:14 Page 264 MASTER ➁ Chapter 12 ● Process Diagrams CENTRIFUGAL PUMPS POSITIVE DISPLACEMENT PUMPS Positive Displacement Positive Displacement Vertical Progressive Cavity Horizontal Screw Pump Gear Pump Vertical Screw Pump Sump Pump Vertical Vertical Can Vacuum Pump Pump Reciprocating Pump STORAGE SYMBOLS Dome Roof Open Top Tank Tank Bin Tank Tank Internal Floating Double Wall Roof Tank Tank Cone Roof Tank Drum Sphere Onion Tank External Floating Roof Figure 12.11 Pumps and Tanks Figures 12.11 and 12.12). In most cases, the compressor symbol is slightly larger than the pump symbol. In the multistage, centrifugal compressors, the narrowing of the symbol from left to right denotes compression of the gas before it is released. This is in sharp contrast to the steam turbine symbol, which illustrates the opposite ef- fect as the steam expands while passing over the rotor. Modern P&IDs show the motor symbol connected to the driven equipment. This equipment may be a pump, compressor, mixer, or generator. Figure 12.12 illustrates the standardized symbols for compressors, steam turbines, and motors. Heat Exchangers and Cooling Towers Heat exchangers and cooling towers are two types of industrial equipment that share a unique relationship. A heat exchanger is a device used to 264
  15. 15. 30678_12_ch12_p251-270.qxd 06/09/2006 11:14 Page 265 MASTER ➁ Review of Basic and Specialized Symbols CENTRIFUGAL COMPRESSORS PD COMPRESSORS T Reciprocating Centrifugal Centrifugal Compressor Compressor Rotory Compressor (Turbine Driven) Rotary Compressor Compressor & Silencers Centrifugal Rotary Screw Compressor Compressor Liquid Ring Vacuum Centrifugal Blower Positive Displacement Blower Axial Compressor Reciprocating Compressor STEAM TURBINE MOTORS Agitator or Mixer Motor Turbine Driver Doubleflow Turbine Diesel Motor Figure 12.12 Compressors, Steam Turbines, and Motors transfer heat energy between two process flows. The cooling tower per- forms a similar function, but cooling towers and heat exchangers use dif- ferent scientific principles to operate. Heat exchangers transfer heat energy through conductive and convective heat transfer, whereas cooling towers transfer heat energy to the outside air through the principle of evaporation. Figures 12.13 and 12.14 illustrate the standard symbols used for heat exchangers and cooling towers. The symbol for a heat exchanger clearly illustrates the flows through the device. It is important for a process technician to be able to recog- nize the shell inlet and outlet and the tube inlet and outlet flow paths. A heat exchanger with an arrow drawn through the body illustrates whether the tubeside flow is being used to heat or cool the shellside fluid. The downward direction indicates heating; the upward direction il- lustrates cooling. 265
  16. 16. 30678_12_ch12_p251-270.qxd 06/09/2006 11:14 Page 266 MASTER ➁ Chapter 12 ● Process Diagrams Figure 12.13 Plate and Frame Heat Exchangers Heat Exchanger Hairpin Exchanger Air Cooled Exchanger U-Tube (Louvers Optional) Heat Exchanger Double-Pipe Single Pass Heat Exchanger Heat Exchanger C C Spiral Heat Exchanger Reboiler Heater Condenser Shell and Tube Heat Exchanger Figure 12.14 Cooling Towers INDUCED DRAFT Crossflow FORCED DRAFT Counterflow HYPERBOLIC NATURAL DRAFT Chimney Tower Counterflow 266
  17. 17. 30678_12_ch12_p251-270.qxd 06/09/2006 11:14 Page 267 MASTER ➁ Review of Basic and Specialized Symbols Figure 12.15 Furnace and Boiler Furnace Boiler The symbol for a cooling tower is designed to resemble the actual device in the process unit. Cooled product flows out of the bottom of the tower and to the processing units. Hot water returns to a point located above the fill. The symbol will not show all of the various components of the cooling tower system, but it will provide a technician with a good foundation in cooling tower operation and enough information to clearly see the process. Furnaces and Boilers The standard symbols file for furnaces and boilers is shown in Fig- ure 12.15. If a proprietary process includes several types of equipment not typically found on a standard symbol file, the designer will draw the device as it visually appears in the unit. Distillation Columns Distillation columns come in two basic designs, plate and packed (Fig- ure 12.16). Flow arrangements vary from process to process. The sym- bols allow the technician to identify primary and secondary flow paths. Distillation is a process designed to separate the various components in a mixture by their boiling points. (See Chapter 15.) A distillation column is the central component of a much larger system. This system typically in- cludes all of the equipment symbols found in this chapter. Plate distillation columns include sieve trays, valve trays, and bubble-cap trays. Packed columns are filled with packing material, rings, saddles, sulzer, and rosette. Reactors Reactors (Figure 12.17) are stationary vessels and can be classified as batch, semibatch, or continuous. A reactor is designed to allow chemi- cals to mix together under specific conditions to make chemical bonds, break chemical bonds, or make and break chemical bonds to form new products. 267
  18. 18. 30678_12_ch12_p251-270.qxd 06/09/2006 11:14 Page 268 MASTER ➁ Chapter 12 ● Process Diagrams Figure 12.16 Distillation Symbols PLATE TOWER PACKED TOWER Bubble-cap, Sieve, Valve Saddle, Ring, Sulzer, Rosette Single Pass Demister Spray Nozzle Chimney Two Pass Packed Section Draw Off Generic Tray Manway Vortex Breaker Sources of Information for Process Technicians Information used by process technicians comes from a variety of sources. Some of these sources are: • Operating training manuals • Process descriptions • Process control manuals • Equipment summaries • Safety, health, and environment regulations • Operating procedures • Startup and shutdown procedures 268
  19. 19. 30678_12_ch12_p251-270.qxd 06/09/2006 11:14 Page 269 MASTER ➁ Summary Figure 12.17 Reactor Symbols Hydrocracking Hydrodesulfurization Reformer Fluid Catalytic Fluid Coking Tubular Fluidized Cracking Reactor Reactor Mixing Reactor Alkylation • Emergency procedures • Process diagrams • Technical data books • Detailed equipment vendor information Summary Process flow diagrams (PFDs) and process and instrument drawings (P&IDs) are used to outline or explain the complex flows, equipment, in- strumentation, electronics, elevations, and foundations that exist in a process unit. A PFD is a simple flow diagram that describes the primary flow path through a unit. A P&ID is a complex representation of the various units found in a plant. Standardized symbols and diagrams have been developed for most pieces of industrial equipment, process flows, and instrumentation. 269
  20. 20. 30678_12_ch12_p251-270.qxd 06/09/2006 11:14 Page 270 MASTER ➁ Chapter 12 ● Process Diagrams Review Questions 1. Describe a process flow diagram and a process and instrument drawing. 2. Draw the symbols for a gate, globe, and automatic valve. 3. Draw the symbols for a centrifugal pump and positive displacement pump. 4. Draw the symbols for a blower and a reciprocating compressor. 5. Draw the symbols for a steam turbine and centrifugal compressor. 6. Draw the symbols for a heat exchanger and a cooling tower. 7. Draw the symbols for a packed distillation column and plate distillation column. 8. Draw the symbols for a furnace and a boiler. 9. Draw a simple process flow diagram using the symbols from questions 2–8. 10. What information is obtained from a loop diagram? 11. What information is available on electrical one-line diagrams? 12. What information is contained on a plot plan drawing? 270