Process technology equipment and systems chapter 12&13

Process technology equipment and systems chapter 12&13, Process Diagram & Utility Systems

285 Process Diagrams O BJECTIVES 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. • 285 Chapter 12 ● Process Diagrams 286 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 e ngineering 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 Types of Process Diagrams 287 Figure 12.1 Process and Instrument Symbols Globe Valve Pneumatic Valve Gate Valve Three-Way Valve Shell & Tube Heat Exchanger Bleeder Valves Rotary Compressor Manual Valve Steam Turbine Compressor & Silencers Butterfly Butterfly Butterfly Ball Solenoid Back Pressure Regulator Pressure Reducing Regulator S VALVES TA N K S PUMPS & TURBINE COMPRESSORS HEAT EXCHANGERS Bin Mixer XXXXXX LLL VESSELS Liquid Ring Compressor Kettle Plate & Frame Spiral U-Tube Centrifugal Compressor Centrifugal Compressor (Turbine Driven) T Ball Four-Way Needle Angle Relief LINE SYMBOLS Major Process Minor Process Pneumatic Hydraulic Capillary Tubing Electromagnetic Signal Electric Future Equipment FURNACE STIRRED REACTOR Cooling Tower Cooling Tower BOILER PLATE Distillation Column Gauge Orifice Rotameter Vacuum Pump Positive Displacement Progressive Cavity Screw Pump Reciprocating Pump Sump Pump Horizontal Centrifugal Centrifugal Centrifugal Vertical Screw Pump Gear Pump Air Cooled Exchanger (Louvers Optional) Double-Pipe Heat Exchanger C C Condenser Heater Single Pass Chimney Two Pa s s Draw Off Generic Tra y Demister Spray Nozzle Packed Section Manway Vor tex Breaker Bullet Hemispheroid Tank Sphere Internal Floating Roof Tank Floating Roof Tank Cone Roof Tank INDUCED DRAFT Crossflow NATURAL DRAFT Counterflow SAFETY (Gases) Plug Check Diaphragm Pinch Valve Stop Check Knife Valve Rotary Screw Compressor Flow Indicator Flow Transmitter Flow Recorder Pressure Indicator Pressure Transmitter FI FT FR PI PT Temp Indicator Temp Transmitter Temp Recorder Level Indicator Level Transmitter Level Controller TI TT TR LI LT LC LR Level Recorder TC Temp. Controller PR Pressure Recorder Pressure Controller PIC 65 55 55 65 65 55 Flow Controller FC PIC PRC LA 105 40 25 I P Transducer Pressure Indicating Controller (DCS) Pressure Recording Controller Level Alarm FE Flow Element TE Temperature Element LG Level Gauge AT Analyzer Transmitter Reciprocating Compressor Chapter 12 ● Process Diagrams 288 during their initial training period. Knowing and recognizing these symbols is important for a new technician. The chemical processing industry has a ssigned a symbol for each type of valve, pump, compressor, steam tur- bine, heat exchanger, cooling tower, basic instrumentation, reactor, dis- tillation column, furnace, and boiler (Figure 12.1A). There are symbols to represent major and minor process lines and pneumatic, hydraulic, or elec- tric lines, and there is a wide variety of electrical symbols (Figure 12.1B). Flow Diagrams New technicians are required to study a simple flow diagram of their a ssigned 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. Flow Indicator Flow Transmitter Flow Recorder Pressure Indicator Pressure Transmitter FI FT FR PI PT Temp Indicator Temp Transmitter Temp Recorder Level Indicator Level Transmitter Level Controller TI TT TR LI LT LC F I C 55 Variable Being Measured Remote Location (board mounted) Control Loop Instrument Remote Location (behind control panel) Field Mounted LR Level Recorder TC Temp Controller PR Pressure Recorder Pressure Controller PC 65 55 55 65 65 55 Flow Controller FC PIC PRC LA 105 40 25 I P Transducer Pressure Indicating Controller Pressure Recording Controller Level Alarm FE Flow Element TE Temperature Element LG Level Gauge AT Analyzer Transmitter What It Does Figure 12.1 Process and Instrument Symbols (continued) Types of Process Diagrams 289 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. Typi- cal 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. Figure 12.2 Process Flow Diagram (PFD) Furnace Feed Tank Bottoms Tank Boiler Cooling Tower Reactors Product Tank 2 Product Tank 1 Vacuum Pump Column Drum Chapter 12 ● Process Diagrams 290 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 variety of elements, including flow diagrams, equipment locations, eleva- tion plans, electrical layouts, loop diagrams, title blocks and legends, and foundation 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 e quipment symbols, abbreviations, unit name, drawing number, revision number, Figure 12.3 Process and Instrument Diagram (P&ID) F-105 Tk-10 Tk-16 B-105 CT-105 Rx-105 C-105 FCV I/P TT TC I/P PT PC PCV I/P LT LC I/P I/P LT LC TE TT TC I/P P-10 P-11 Rx-106 P-12 V-1 D-105 Tk-12 Tk-14 P-13 P-14 V-2 V-3 V-4 V-5 V-6 EX-105 V-7 P-15 FT FC Types of Process Diagrams 291 Figure 12.4 Process Legend Globe Valve Gate Valve Three-Way Valve Bleeder Valves Manual Operated Valve Gauge Orifice SAFETY (Gases) Ball Solenoid Valve CLOSED S Rotameter Four-Way Angle Plug Diaphragm Butterfly Check Valve Relief Valve Pneumatic Pneumatic Pinch Valve Stop Check Knife Valve INDUCED DRAFT Crossflow NATURAL DRAFT Counterflow FURNACE BOILER Vacuum Pump Centrifugal Drum Gear Pump Positive Displacement Dome Roof Tank Sphere Rotary Screw Compressor Progressive Cavity Screw Pump Reciprocating Pump Sump Pump Horizontal Vertical Internal Floating Roof Tank Cone Roof Tank Plate-and-Frame Heat Exchanger Air-Cooled Exchanger (Louvers Optional) Double-Pipe Heat Exchanger C C Spiral Heat Exchanger Condenser Heater Single Pass Chimney Two Pass Draw Off Generic Tra y Demister Spray Nozzle Packed Section Manway Vor tex Breaker VALVE SYMBOLS EQUIPMENT SYMBOLS Minor Process Pneumatic Hydraulic Capillary Tubing Electromagnetic,Sonic Optical,Nuclear XX XX LLL Major Process Future Equipment Connecting Line Nonconnecting Line Nonconnecting Line Jacketed or Double Containment Mechanical Link Software or Data Link •••• Electric Flow Indicator Flow Transmitter Flow Recorder Pressure Indicator Pressure Transmitter FI FT FR PI PT Temp Indicator Temp Transmitter Temp Recorder Level Indicator Level Transmitter Level Controller TI TT TR LI LT LC LR Level Recorder TC Temp. Controller PR Pressure Recorder Pressure Controller PC 65 55 55 65 65 55 Flow Controller FC PIC PRC LA 105 40 25 I P Transducer Pressure-Indicating Controller Pressure-Recording Controller Level Alarm FE Flow Element TE Temperature Element LG Level Gauge AT Analyzer Transmitter APPROVED GENERAL LEGEND DRAWING NUMBER REVISION 1 P C E DATE 10-6-10 PAGE 1 OF 30 OO6543 DISTILLATION UNIT LINE SYMBOLSEQUIPMENT CONT. INSTRUMENT SYMBOLS PREFIXES ABBREVIATIONS CW- cooling water MU- makeup FW- feedwater SE- sewer RX- reactor UT- utilities CA- chemical addition IA- instrument air D- drum C- column CT- cooling tower TK-tank F- furnace EX- exchanger P- pump V- valve Chapter 12 ● Process Diagrams 292 approvals, and company prefixes. Because symbol and diagram stan- dardization is not complete, many companies use their own symbols in unit drawings. Unique and unusual equipment will also require a modified s ymbols 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 equip- ment location. This information is important for making rounds, checking Figure 12.5 Foundation N W E S 64' 0" 28' 0" 28' 0" 6' 0" 8' 0" 10' 0" 6-8-10 Method 2' x 64' x 18" Load-Bearing Beam 18" 4" 12" Estimating Materials: Cu. yds. ϭ Width Length Thickness 27 Remesh Remesh Over Plastic Remesh Rebar in All Beams 32' 0" 90 Types of Process Diagrams 293 equipment, developing checklists, catching samples, and performing start- ups and shutdowns. Electrical Drawing Electrical drawings (Figure 12.7) include symbols and diagrams that d epict 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 con- trol 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 electri- cal systems. The primary safety system is the isolation of the hazardous e nergy “lock-out, tag-out” permit. Process technicians are required to have training in this area. Figure 12.7 shows the basic symbols and flow path a ssociated 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 trans- formers. Electric breakers are designed to interrupt current flow if design c onditions are exceeded. Breakers are not switches and should not be Figure 12.6 Elevation Drawing EL 16' 0" EL28' 0" EL-40' 0" TK-105 RX-105 TK-200 TK-300 RX-106 RX-300 C-300 D-56 Chapter 12 ● Process Diagrams 294 Figure 12.7 Electrical Drawing V Voltmeter: measures voltage V s Voltmeter Switch 27 Power Transformer: reduces high voltage Potential Transforming Symbol Under Voltage Relay M Motor MCC Motor Control Center Switch Fuse Circuit Breaker: a protective device that interrupts current flow through an electric circuit A A s 50 51 Ammeter: measures electric current Ammeter switch Transformer Overcurrent Relay (Instantaneous) Transformer Overcurrent Relay (Time delay) Motor Circuit Contacts Current Transformer: reduces high voltage to instrumentation. BOILER Steam Turbine Generator 69,000 Volts 69 KV 13,200 V 13, 800 V 2,300 V 13.2 KV 13.8 KV 2.3 KV On Off Motor 2.3 KV or 480 Volts 51 MAIN TRANSFORMER A s A 27 V V s MCC #1 480V BUS MAIN POWER DISTRIBUTION ELECTRIC POWER PLANT M M Motor Starter Motor Starter . diagrams and the information they contain. • Draw a process flow diagram. • Draw a process and instrument drawing. • Describe the various process equipment. drawing. Types of Process Diagrams Process diagrams can be broken down into two major categories: process flow diagrams (PFDs) and process and instrument