Process equipment construction materials

Information on manufacturing processes, equipment parameters, materials of construction, costs and the physical properties of process materials are needed at all stages of design from the initial screening of possible processes, to the plant start-up and production. 

Information about process equipment including materials of construction, electrical classification, relief systems, HVAC, design codes and standards, material and energy balances, safety systems, and piping and instrumentation diagrams (P lDs) must also be identified and assembled. 

Selection of Equipment The principal factors which influence mixing-equipment choice are (1) the process requirements, (2) the flow properties of the process fluids, (3) equipment costs, and (4) construction materials required. 

Polyester resins, reinforced with glass fibers, are used widely in the construction of process equipment. Some physical and mechanical properties are presented in Table 3.48. Table 3.49 lists various materials used as filler and the properties they impart to different plastics. 

This chapter covers the selection of materials of construction for process equipment and piping. 

Typical values of the mechanical properties of the more common materials used in the construction of chemical process equipment are given in Table 7.2. 

Process equipment information must include at least (1) materials of construction ... 

Process equipment design and materials must be documented by identifying the applicable codes and standards (e g., ASME, ASTM, API). If the codes and standards are not current, the DOE contractor must document that the design, construction, testing, inspection, and operation are still suitable for the intended use. If the process technology requires a design that departs from the applicable codes and standards, the contractor must document that the design and construction are suitable for the intended purpose. 

Before the HAZOP study is started, detailed information on the process must be available. This includes up-to-date process flow diagrams (PFDs), process and instrumentation diagrams (P IDs), detailed equipment specifications, materials of construction, and mass and energy balances. 

The main business of most chemical companies is to manufacture products by means of controlled chemical reactions. The reactivity that makes chemicals useful can also make them hazardous. Chemical reactions are usually carried out without mishap, but sometimes they get out of control because of problems such as the wrong or contaminated raw material being used, changed operating conditions, unanticipated time delays, failed equipment, incompatible materials of construction, or loss of temperature control. Such mishaps can be worse if the chemistiy under both normal and abnormal conditions is not fully understood. Therefore, it is essential that chemical process designers and operators understand the nature of the reactive materials andchemistry involved and what it takes to control intended reactions and avoid unintended reactions throughout the entire life cycle of a process facility. 

Other, more specific decisions are made in process design, including the actual choice of equipment (e.g., more than ten different types of heat exchangers are available) and the selection of construction materials of various process units. 

Process flowsheet Unit operations Equipment geometry. Materials of construction. 

Because carbon is difficult to machine, very litde impervious carbon equipment is made. However, impervious graphite has been accepted as a standard material of construction by the chemical process industry for the fabrication of process equipment, such as heat exchangers, pumps, valves, towers, pipe, and fittings (9,10). 

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