API Codes

Tank Roof. The roof of a vertical cylindrical tank is treated like a building stmcture and uses the same basic rules as the building codes. For example, the API codes require a roof to be designed for the dead load plus a 122-kg/m (25-lb /ft ) Hve load. The minimum fabrication thickness of roof plates is 3/16 in. (4.8 mm). 

The API Code RP-520 [33a] suggests the following to determine the liquid expansion rate to protect liquid-filled (full) systems or locations where liquid could be trapped in parts of a system or an area could be subject to blockage by process or operational accident. When thermal input from any source can/could cause thermal expansion of the enclosed liquid ... 

Due to gas expansion from external fire, the API code [10] provides for calculation of the pressure relief valve orifice area for a gas containing vessel exposed to external fire on die unwetted surface ... 

The process designer and project engineer should classify the various areas of a plant following NEPA-70, Article 50528.29 order to advise the electrical and other project team members of the degree of electrical hazards anticipated. The appropriate equipment (motors, instruments, conduit, wiring, etc.) should be specified according to NEPA-70, Article 500 and others as applicable, the ASME Code and the API Code as appropriate. See NEPA-497A and... 

The ASME Pressure Vessel Code [1] and the API codes or recommended procedures [10, 13, 33] recognize and set regulations and procedures for capacity design, manufacture and installation of rupture disks, once the user has established the basis of capacity requirements. 

Low absolute pressure calculations, 129 Low pressure system, 129 American Petroleum Institute, 399 American Society of Mechanical Engineers, 399 API Codes, 399 API oil field separators, 239 API, heat absorbed from fire, 451-453 Babcock steam formula, 103, 107, 108 Back pressure, 404 Effect of, 407, 408 Baffles, lank mixing, 311 Diagrams, 330 Bag filters/separators, 270 Bag materials, 274 Cleaning, 272, 273 Heavy dust loads, 271 Specifications, 271 Temperature range, 271 Bins, silos, hoppers venting, 516 Blast pressure, 496 Blowdown, 404... 

Low-pressure models applicable to the protection of process buildings and storage tanks ruled by the API codes. RUST s low-pressure model is usually successful for vent design of internal or external overpressure. 

Larson, R.J., Vapor Accumulations within Covered Floating Roof Tanks, Annual Meeting of API Codes and Standards Committee, Los Angeles, CA, May 4, 1966. 

Alpha method The alpha procedure was derived by Drewry, Weidler, and Hwong (1977) from the same data set used for the original lambda correlation. For pile-capacity calculations the procedure utilizes a multiplier a on the undrained shear strength (Su) of the clay. The API code has traditionally recommended a value of 1.0 for Gulf of Mexico-type clays or a value that varies with strength for other types of clays. The API (2000) code varies the a value with the ratio of undrained soil strength to effective soil overburden ( / = S /a ) is as given in Equation 10.21 ... 

Many tanks require emission controls, and some require emergency pressure relief. These should be in accord with the API code relevant to the tank design and with NFPA 30 and 29 CFR 1910.106. The NFPA also regulates spacing of tanks. Finally, the use of inertion to prevent explosions will make an installation safer and will allow closer grouping of tanks. This is covered in NFPA 69. 

In accordance with the API code the misalignment must not exceed 1.6 mm. 

TDI tanks can be made from carbon steel (ASTM A 285 Grade C) or from stainless steel (Type 304 or 316). API Code 650 specifies V4-in steel for the bottom and /i6-in for the shell and roof. 

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