What is API RP 934-A PDF and Why Should You Care? A Brief Introduction to Materials and Fabrication of Heavy Wall Pressure Vessels for High-temperature, High-pressure Hydrogen Service
this practice is intended to provide guidance for the selection of the appropriate pressure vessel materials and fabrication procedures for the fabrication of pressure vessels that operate at high pressure and high temperature. it does not establish minimum mechanical properties or safety standards for pressure vessels. pressure vessels certified to standards may be used where the design is based on published documents and other information. this document may also be used as a resource when planning to modify existing pressure vessels. the interior surfaces of these pressure vessels may have an austenitic stainless steel, ferritic stainless steel, or nickel alloy weld overlay or cladding to provide additional corrosion resistance. this recommended practice is applicable to wall (shell) thicknesses from 1 in. (25 mm) to 4 in. (100 mm). integrally reinforced nozzles, flanges, tubesheets, bolted channel covers, etc. can be greater than 4 in. at shell or head thicknesses greater than 4 in.
Api rp 934 a PDF
aapi recommends that the plain carbon steel (0.035 in. thick) used to form the shell in the asme classification 40 be coated with a zinc-chromium electroplated layer or a nickel-chromium coating. in some instances, api may recommend that the shell be clad with a high-strength alloy to prevent corrosion in the environment in which it will be used. api recommends that if the general process of the pressure vessel is not known to the user, that the pressure vessel be inspected and tested prior to installation. a test for minimum hoop strength with a minimum 5-in. (127-mm) shell and head is recommended for all sections of vessel, including nozzles. if the hoop strength test is negative, the pressure vessel must be tested for minimum tensile strength and minimum yield strength. only those pressure vessels that fail the tests should be installed. for boilers, api recommends that the shells be lined with a corrosion-resistant material. if the corrosion-resistant material is a passive material, this material should be applied to the inner surface of the shell. if the corrosion-resistant material is an active material, a suitable method of applying this material should be provided. api has provided a list of corrosion-resistant materials that may be used.