Industrial Communication Skills: Plant Line Tracing PDF

Unit A-10 • Fundamental Industrial Communication Skills Objective 5 Complete a plant line tracing. Plant Line Tracing It has been a long-standing practice for Power Engineers in training to trace the plant processes by constructing a single line sketch at the site where they work. Usually, a typic...

Unit A-10 • Fundamental Industrial Communication Skills Objective 5 Complete a plant line tracing. Plant Line Tracing It has been a long-standing practice for Power Engineers in training to trace the plant processes by constructing a single line sketch at the site where they work. Usually, a typical formal line diagram of a plant or system is very complicated. The novice may find it difficult to understand. It is a good idea to keep these diagrams for reference, and trace them physically. Single line sketches are simple to construct. Free hand sketches are often acceptable. Power Engineers often use note books or sketch pads that are easy to carry, and draw rough drafts of the sketches in pencil for easy revision. Figure 18 is an example of a drawing made by a Power Engineer in training. Figure 18 – Single Line Sketch of Water Treatment System from Engineer in Training 1-18 4th Class Edition 3 • Part A Energy Plant Sketching • Chapter 1 The sketch is a fair representation of the water treatment system. However, a number of features need to be pointed out: • This is a rough sketch and does not include all the features of the system, just those pertinent to the discussion. • The sketch contains both hand drawn and computer drafted elements • The sketch layout does not accurately represent the spatial connections between different equipment as it tries to minimize lines from crossing. • Pipe sizing is not shown. • Not all process flows are indicated. • Not all valves are shown. • Only a generic symbol for valve is used. • A plant specific symbol for pump is used. Final copies of sketches are often coloured to add additional value for later reference. These colours are applied for varying reasons including: • To clearly identify all the different pieces of equipment clearly. • To set apart the different processes (arbitrary colours). • Piping lines connecting the equipment may also be coloured to indicate fluid type and flow. Different plants will identify their piping colours in different ways. Some universal colour indications to identify fluids are generally recommended in registered plants. The following recommendations reflect those outlined in the ASME A13.1 Pipe Marking Standard. In this standard, labels are placed: • Adjacent to all valves and flanges. • Adjacent to all changes in pipe direction. • On both sides of wall, floor, or ceiling penetrations. • Every 7.5 to 15 meters on straight runs of pipe. Table 1 provides an overview of this pipe-labelling standard. Table 1 – ASME A13.1 Piping Labelling Overview Material Properties Letter Colour on Field Colour Example Flammable: fluids that are a vapour or produce vapours which can ignite and continue to burn in air Black on Yellow → Ammonia → Combustible: fluids that may burn but are not flammable White on Brown → Diesel Fuel → Toxic & Corrosive: fluids that are corrosive or toxic produce corrosive or toxic substances Black on Orange → Sulfuric Acid → White on Red → Fire Sprinkler → Other water: any other water, except water used in sprinkler and firefighting piping systems White on Green → Boiler Feed → Compressed air: any vapour or gas under pressure that does not fit the category above White on Blue → Compressed Air → Fire quenching: water and other substances used in sprinkler firefighting piping systems 4th Class Edition 3 • Part A 1-19 Unit A-10 • Fundamental Industrial Communication Skills The following are some of the acceptable practices used in tracing. a) Standardized symbols, such as those provided in this chapter, are often used to simplify learning, and provide clarity of the process. b) Adding personal notes to help remark on specific operating conditions. For example: i. “Manual main fuel valve is very sensitive to tripping. Open with care, slow and steady.” ii. “High point vent valve on the top of the domestic hot water tank is located 10 m east of the sodium zeolite softeners, and 3 m from the ground. Scaffolding and fall arrest requirements applies.” iii. “Note: Actual location and position of equipment are not included with PFDs and P&IDs.” iv. “Pipe designated colour coding: plant specific or ASME. • The plant may have its own documented colour coding for different piping containing different fluids. For example, water (blue), steam (red), and gas (yellow).” c) Verify that the information is up-to-date. Record and report any discrepancies for updates and revisions. d) Compare the personal hand drawn sketch with the current formal diagrams to improve learning and understanding of the process. e) For many plant sites, one of the major parts of the competent qualification requirement for a trainee is to i. Sketch a single line diagram on a white board from memory. ii. Explain the process with the aid of the sketch. iii. Answer questions from a selected group of evaluators; including senior operators, supervisors, and trainers. Well-prepared and accurate personal hand drawn single line sketches are often compared to well written school notes. They are helpful for the successful training and development of learners. In this case, they are the Power Engineers training in a plant site. Complete A Trace Drawing Using Figure 19, create a line trace drawing of the fuel lines in the photo. The fuel lines are yellow. In every new plant or area of work, a new set of line trace drawings will need to be completed. Initially, review the formal plant diagrams. Then physically trace the lines in the field (plant). 1-20 4th Class Edition 3 • Part A Energy Plant Sketching • Chapter 1 Figure 19 – Boiler Gas Train (Courtesy of GPRC Power Lab) On the formal diagrams of a different gas train (Figure 20), the lines, valves, and instrumentation are all in a nice line. In the field, they may be all over. Tracing is necessary to know the physical location of all isolation valves, fittings, and instrumentation. Figure 20 – Gas Train P&ID Natural Gas DN PCV 25 Vent DN6 P6-F-001 35 kPa STR HV DN80 Isolation HV PSLL PI HV TP M PI DN 40 Vent S PI HV M PSH HV TP PI DN10 TP DN80 DN80 20 kPa DN6 DN6 HV PI Pressure Indicator HV PSL Hand Valve Pressure Control Valve Motorized Valve Safety Shut Off Valve Strainer Test Point Pressure Switch Low PSH Pressure Switch High PCV M S STR TP CV SV Pilot Line PI DN10 HV DN40 Vent DN15 Vent BMU HV TP PI S S PCV FCV S DN80 RF HV DN10 x DN6 DN6 DN10 DN6 Firing Hand Valve DN6 DN6 Burner Flow Control Valve Solenoid Valve REFERENCE DIAGRAMS GENERAL NOTES REVISIONS EQUIP TAG # PanGlobal Training Systems DRAWN BY Date TITLE P & ID Fuel and Burner Water Tube Boiler APPROVED Date NO BY CKD DESCRIPTION Date SCALE DWG# N.T.S. 4th Class Edition 3 • Part A 300 - WT01 - 01 REV A 1-21 Unit A-10 • Fundamental Industrial Communication Skills To initiate the drawing from Figure 19, start at the left side of the photo. a) The first item to draw is the isolation valve on the vertical line. b) A drip leg, or dirt pocket is under the “T” going to the gas train. c) Another isolation valve followed by a pressure gauge (shown as “PI” for Pressure Indicator), then a “Y” strainer. d) A pressure-regulating valve is next, which also has a vent line that is vented outdoors. e) After the PRV is a low gas pressure switch and pressure indicator (the switch is hard to see in the photo, it is behind the gauge). f ) Coming off the main line is the small tubular line for the igniter. g) Show the isolation valve, “Y” Strainer, then follow the stainless steel line up to the solenoid valve, before it enters the burner assembly. h) On the main line again, there are two power-actuated valves. There is a vent between them with a normally open (open when there is no power, closed when the powered valves are open) solenoid valve vented to the outside. i) Next is another pressure switch and pressure indicator (not visible in the photo). j) Closer to the burner is another isolation valve (a firing valve), and the control valve that modulates how much fuel is allowed to the burner. Self-Test 1 Make a formal P&ID of the sketch of the boiler gas train below. 1-22 4th Class Edition 3 • Part A Energy Plant Sketching • Chapter 1 Chapter Summary Being able to communicate is critical to the operating environment of an energy plant. Often this communication is best handled by a visual representation. Power Engineers are regularly required to make sketches of plant equipment and components, both individually and within the system. This is an effective learning tool to understand how plants work. It is an additional tool that helps identify physical operating characteristics that may be improved upon. Knowledge of how the system functions and the interrelationship of equipment is critical to effectively manage operating processes. 4th Class Edition 3 • Part A 1-23 Unit A-10 • Fundamental Industrial Communication Skills 1-24 4th Class Edition 3 • Part A Energy Plant Sketching • Chapter 1 Knowledge Exercises – Chapter 1 Name: Date: Instructor: Course: Objective 1 1. Identify two ways to successfully hand sketch a circle. 2. What important characteristic does dimensioning supply to a basic sketch? Objective 2 3. What are the six possible views used in an engineering diagram? Objective 3 4. In a sectional drawing, how is refractory and steel differentiated in a boiler shell? Objective 4 5. Draw the following symbols: turbine, flow indicator, pump, temperature recorder. 4th Class Edition 3 • Part A 1-25 Unit A-10 • Fundamental Industrial Communication Skills Chapter 1 (Cont.) Objective 5 6. Without any in-plant guide, on a plant piping diagram, what would the following labels indicate? a. White Lettering on Green background b. Black Label on Orange background c. White Label on Brown Background 7. Line tracing sample: Prepare a detailed sketch of the gas train pictured below. Identify the important components. 1-26 4th Class Edition 3 • Part A