ASTM A380/A380M-17 pdf free.Standard Practice for Cleaning, Descaling, and Passivation of Stainless Steel Parts, Equipment, and Systems.
This practice covers recommendations and precautions for cleaning, descaling, and passivating of new stainless steel parts, assemblies, equipment, and installed systems. These recommendations are presented as procedures for guidance when it is recognized that for a particular service it is desired to remove surface contaminants that may impair the normal corrosion resistance, or result in the later contamination of the particular stainless steel grade, or cause product contamination. The selection of procedures from this practice to be applied to the parts may be specified upon agreement between the supplier and the purchaser. For certain exceptional applications, additional requirements which are not covered by this practice may be specified upon agreement between the supplier and the purchaser. Although they apply primarily to materials in the composition ranges of the austenitic, ferritic, martensitic, and duplex stainless steels, the practices described may also be useful for cleaning other metals if due consideration is given to corrosion and possible metallurgical effects.
7. Inspection After Cleaning
7.1 General—Inspection techniques should represent careful, considered review of end use requirements of parts. equipnient. and systems. There is no substitute for good, uniform, cleaning practices which yield a metallurgically sound and smooth surface, followed by adequate protection to preserve that condition. Establishment of the most reliable tests and test standards for cleanness are helpful in attaining the desired performance of parts. equipment. and systems. Testing should be suñiciently extensive to ensure the cleanness ot all surfaces exposed to process fluids when in service. The tollowing represent some tests that have been successfully applied to stainless steels. The urchaser shall have the option of specifying in his purchase documents that any of these quality assurance tests be used as the basis for acceptability of the cleanness of the stainless steel item, the absence of iron on the surface, or both.
8.5.7 Installed piping systems are often laid up wet, that is, they are filled with water (or process fluid) after in-place cleaning until ready to be placed in service. Storage water should be of the same quality as the makeup water ftr the system, and should be introduced in a manner that it directly replaces the final flush water without pennitting the internal surfaces of the system to dry.
8.5.8 Equipment and assemblies br critical applications may be stored and shipped with pressurized. dry. filtered. oil-free nitrogen to prevent corrosion until they are ready to be installed. Means shall be provided for maintaining and mombring the gas pressure during shipping and storage. If the item is to be shipped to or through mountains or other areas where the altitude varies greatly from that where it was pressurized. consideration must be given to the effect of that change in altitude on the pressure inside the item, and possible rupture or loss of seals.
8.5.9 Pressure-sensitive tape is often used for sealing or protective covers, seals, caps. plugs, and wrappings. If possible, the gummed surface of the tape should not come in contact with stainless steel surfaces. It’ tape has come in contact with the metal, clean it with solvent or hot water, and vigorous scrubbing.