Flowsheets Piping

Spend a day reviewing available process flowsheets, piping and instrument drawings, and operating manuals. Unless you have had an operating job before, you will not be able to understand the unit fully from these documents alone. Next, study the unit in the field. This is difficult and may easily take a week. 

A separate table such as the example in Table 15-2 is prepared for each line designation. Each valve is assigned a designation on the flowsheets and explained in this table. The pipe, valves, and fittings table can sp( acceptable valves by manufacturer and model number, by a generic description, or by a combination of the two as shown in the example. It should be pointed out that Tables 15-1 and 15-2 are examples from American Petroleum Institute Recommended Practice (API RP) 14E and are illustrative only. There are almost as many different formats for pipe, valve, and fip "" tables as there are companies, and these examples are in no manner ty or recommended. Often, for. simphcity, valve types are not described i pipe, valve, and fittings specifications but on separate sheets for each. ... 

Used to present the heat and material balance of a process. This may be in broad block form with specific key points delineated, or in more detailed form identifying essentially every flow, temperature and pressure for each basic piece of process equipment or processing step. This may and usually does include auxiliary services to the process, such as steam, water, air, fuel gas, refrigeration, circulating oil, etc. This type of sheet is not necessarily distributed to the same groups as would receive and need the piping flowsheet described next, because it may contain detailed confidential process data. 

Piping Flowsheet or Mechanical Floiu Diagram, Figures 1-8,... 

The two types of lines on a flowsheet are (1) those representing outlines and details of equipment, instruments, etc., and (2) those representing pipe carrying process or utility liquids, solids, or vapors and electrical or instrument connections. The latter must be distinguished among tliemselves as suggested by Figure 1-21. 

The process designer must also consider the corrosive nature of the fluids involved when selecting construction materials for the various process and utility service lines. Some designers attach these materials designations to the line designation on the flowsheets, while others identify them on the Line Summary Table (Figure 1-24D). Some typical pipe materials designations are ... 

This contributes materially to the readability of the flowsheets. Each line on the flow sheet must represent an actual section or run of piping in the final plant and on the piping drawings. 

In order to coordinate the process flowsheet requirements with the mechanical piping specifications, Line Schedules are prepared as showm in Figure 1-24A through D. The complete pipe system specifications are summarized by codes on these schedules refer to paragraph on Working Schedules. 

V-ll is a typical valve code to use on flowsheets and piping drawings. 

Process flowsheets do not normally show companion flanges for valves unless these serve as blinds or for orifice plates. This detail is sometimes shown on the piping flow-... 

As a direct companion of the completed flowsheet, the line schedule sheet transmits the process and mechanically necessary details for proper interpretation of the piping aspects of the flowsheet (see Figures 1-24A, B, C, D). These schedules are initiated by the process engineer to further explain the requirements of the process as shown on the flowsheets. They are often and perhaps usually cooperatively completed by other engineers, particularly the piping, mechanical and instrumentation groups. 

Combined Process and Piping Flowsheet or Diagram, Figures... 

Current technolog) allows the use of computer programs and data bases to construct an accurate and detailed flowsheet. This may be a process type diagram or a piping and mechanical/instrument diagram, depending on the input. See Figures 1-9, 1-10, 1-18A and 1-18B. 

NOTE 1. Vertical columns indicate valves acceptable as equivalent to the specification description. 2. V-l 1 is a typical valve code to use on flowsheets and piping drawings. 

American Gas Association method, 121 Complex pipe systems, 122 Low pressure air, steam, 131 Panhandle formula, 120, 121 Panhandle-A formula, 121 Parallel system, 122 Series system, 122 Transmission factors, 120 Weymouth formula, 120 Flowsheet symbols, 17... 

Present the MSPS graphically to the user (by highlighting the pipes on the flowsheet, for example). Ask the user to specify any pipes that he or she prefers to keep open. Mark all such pipes as unsatisfactory. If there are no unsatisfactory pipes, return the current SPS as the ASPS. 

Bromberg, I. A Look at an Engineering Contractor s Overhead Costs, Sept. 12,1966, p. 218. Sokullu, E.S. Estimating Piping Costs from Process Flowsheets, Feb. 10,1969, p. 148. 

Figure 2 Reduced flowsheet of the experimental setup. The mass-flow controllers, the three-way valves in the oxidizing and reducing pipes, the multiple-way valve GC and the temperature of the reactor are all computer-controlled.

In this volume, there is an account of the basic theory underlying the various Unit Operations, and typical items of equipment are described. The equipment items are the essential components of a complete chemical plant, and the way in which such a plant is designed is the subject of Volume 6 of the series which has just appeared. The new volume includes material on flowsheeting, heat and material balances, piping, mechanical construction and costing. It completes the Series and forms an introduction to the very broad subject of Chemical Engineering Design. 

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