Piping and instrumentation

The process flow-sheet shows the arrangement of the major pieces of equipment and their interconnection. It is a description of the nature of the process. 

This chapter covers the preparation of the preliminary P and I diagrams at the process design stage of the project. 

---

P IDs (piping and instrumentation diagrams) should identify instruments, sample locations, the presence of sample valves, nozzle blinding, and control points. Of particular importance are the bypasses and alternate feed locations. The isolation valves in these hues may leak and can distort the interpretation of the measurements. 

Piping and Instrument Diagram (P ID) A diagram that shows the details about the piping, vessels, and instrumentation. 

All piping and instrument connections should be made on the lower half of the housing to aid in removal of the top half. Other connections, if they must be made in the top half, should have easily accessible joints. 

Often, more time is spent specifying and discussing accessories than is spent on the basic compressor. This is because the open options are much more numerous. Also, the average user is more familiar with piping and instrumentation, both of which fall into the accessory area. 

The scope of supply includes all the required equipment, piping and instrumentation for proper flaring of gaseous effluents with smoke suppression system. The scope of supply shall include at least ... 

Fig ure 11-23. Piping and instrumentation diagram of a fermenter. (Source Bartow [13], Supersizing the aerobic fermenter," Chem ca Engineering, pp. 70-75, July 1999. Courtesy of Chemical Engineering.)... 

As the process moves from the process development stage to the design and construction stage the chemistry, unit operations, and type of equipment have been set. The design and construction stage needs to focus primarily on equipment specifications, piping and instrumentation design, installation details, and layout for an inherently safer installation. 

FIAZOP is a formally struetured method of systematieally investigating eaeh element of a system for all ways where important parameters ean deviate from the intended design eonditions to ereate hazards and operability problems. The HAZOP problems are typieally determined by a study of the piping and instrument diagrams (or plant model) by a team of personnel who eritieally analyze eflfeets of potential problems arising in eaeh pipeline and eaeh vessel of the operation. 

Piping and Instrument diagrams (P IDs - not shown) may be even more appropriate for showing these details and to provide information for PSA. The P IDs are used to describe the relationships between equipment and instrumentation and other relevant information that enhances clarity. 

This phase is where the basic design work, such as process flow design, is performed. Piping and instrumentation diagrams (P IDs) and equipment... 

Discuss the main differences between a process flow diagram (PFD) and a process piping and instrument diagram (P ID). 

Dettiiled plant descriptions such as piping and instrumentation drawings and flowcharts... 

Drawings should conform to accepted drawing conventions, preferably those laid down by the national standards. The symbols used for flow-sheets and piping and instrument diagrams are discussed in Chapter 4. Drawings and sketches are normally made on detail paper (semi-transparent) in pencil, so modifications can be easily made, and prints taken. 

In most design offices Computer Aided Design (CAD) methods are now used to produce the drawings required for all the aspects of a project flow-sheets, piping and instrumentation, mechanical and civil work. 

---