MATERIALS SELECTION can be defined as follows:
Process of selecting optimum candidate materials which meets the application requirements at the minimum cost.
The optimum materials are generally have the lowest cost/life ratio.
Cost of materials is very important consideration for the materials engineer. Materials of construction for equipment and piping must be economical, as well as meet the design, safety, and reliability requirements of the facility. Materials that possess these attributes are considered to be “cost-effective” for the particular application.
In the oil and gas industry, the presence of hazardous chemicals, elevated temperatures and pressures, and/or corrosive environments can make the selection of cost-effective materials a complicated task.
The cost estimates shown in below table are based on carbon steel prices. It is suggested that these costs be multiplied by a material cost factor, matcost , for other materials. Table shows the suggested values for these material cost factors. These factors are based on a variety of sources from manufacturer’s data and cost quotations.
Table reference: API RP 581
