FACTORS INFLUENCE THE SELECTION OF MATERIALS

The proper selection is a difficult problem because in most cases, the determinants may be conflicting. If corrosion is typical versus cost.  

The main factors that influence are:

1. Fluid Driven -
   Nature and concentration of impurities or fluid
   contaminants, pH, velocity, Toxicity, resistance to corrosion; chance
   contamination;
   
2. Terms of Service -
   Temperature and pressure. (given the extreme conditions, even if transient conditions or possible);
   
3. Stress level of the material -
   The material must have mechanical strength compatible with the magnitude of these efforts. (Fluid pressure, weight, wind loads, thermal expansion reactions, overloads, assembly efforts, etc);
   
4. Nature of Mechanical stress -
   Traction, compression, bending, static or dynamic efforts; s shock, vibration, etc. Efforts cyclical;
   
5. Availability of materials -
   With the exception of carbon steel materials has limited availability;
   
6. System calls -
     Appropriate for the type of material and the type of mounting;
   
7. Cost of materials -
   Often a decisive factor. You should consider the direct cost and indirect costs also represented by the lifetime, and the resulting replacement costs and system downtime;
   
8. Security -
   The greater or lesser degree of security required will depend on the strength and lifetime;
   
9. Easy to fabrication and assembly -
   Among the limitations include the weldability, machinability, ease of shaping, etc.;
   
10.  Previous Experience -
    It is risky to decide on a material that does not know any previous experience in similar service;
    
11. Expected life -
    The lifetime depends on the nature and
    importance of the pipe and the time of return on investment. time
    life for the purpose of project is approximately 15 years;