In Indonesia this week is a busy week, because we have to prepare for lebaran or a long holiday, and that's why piping & fabrication maybe will post only for few days, and after those post, will take a long holiday.
Materials Considerations
Piping systems are fabricated from a great variety of metals and nonmetals, material selection being a function of the environment and service conditions. Materials must conform to the standards and specifications outlined in the governing code. Some codes such as ASME Section III impose additional requirements on materials beyond those in the material specifications. All fabrication and installation practices applied to these materials must be conducted so as to assure that the final installation exhibits all of the properties implicit in the design. For example, hot bending of certain austenitic stainless steels in the sensitization range will reduce their corrosion resistance if they are not subsequently heat-treated. Accordingly, a heat treatment to restore these properties should be specified.
Materials Considerations
Piping systems are fabricated from a great variety of metals and nonmetals, material selection being a function of the environment and service conditions. Materials must conform to the standards and specifications outlined in the governing code. Some codes such as ASME Section III impose additional requirements on materials beyond those in the material specifications. All fabrication and installation practices applied to these materials must be conducted so as to assure that the final installation exhibits all of the properties implicit in the design. For example, hot bending of certain austenitic stainless steels in the sensitization range will reduce their corrosion resistance if they are not subsequently heat-treated. Accordingly, a heat treatment to restore these properties should be specified.
Consideration must also be given to the various types of piping products, their tolerances, alloys, heat-treated conditions, weldability, and formability. Pipe is made by a variety of processes and depending on the method of manufacture can have differing tolerances.
Most product forms also come in a variety of alloys, and the choice of a fabrication process may be governed by the alloy. ASME Section IX has developed a system of P Numbers and Group Numbers. This system groups material specifications by chemical composition and/or physical properties. Those with like compositions and properties are grouped together to minimize the number of welding procedure qualifications required. This method of grouping can also be applied to other fabrication processes as well.
Happy Holiday to all of you and thanks!
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