API 653 - Section 650 EXAM 1 QUESTIONS AND ANSWERS 2024

API 653 - Section 650 EXAM 1 QUESTIONS AND ANSWERS 2024 API 650 covers material, design, fabrication, erection and testing requirements for aboveground welded steel storage tanks. Internal pressure allowed for these tanks approximates atmospheric pressure. However, the internal pressures mus not exceed what criteria? - ANSWERS The weight f the roof plates (1.1.1) What is the maximum temperature permissible for a 'standard tank' covered by API 650, unless additional requirements of appendix M of API 650 are followed? - ANSWERS 200F (1.1.1) Appendix A provides alternative simplified design requirements for tanks where the stressed components, such as shell plates and reinforcing plates. They are limited to a maximum nominal thickness of what (inches)? - ANSWERS 1/2" (1.1.7) Who is responsible for complying with all of the provisions of API 650 when a new tank is built? - ANSWERS The manufacturer (1.3) Required sections of this Standard become mandatory if the Standard has been adopted by _________ - ANSWERS Legal jusrisdiction (3.11) The lowest tempreature considered in the design shall be assumed to be how many degrees Farenheit above the lowest one-day mean ambient temperature of the locality where the tank is to be installed? - ANSWERS 15F (3.4) Material used to construct a tank shall conform to the specifications of API 650. May other material be used? - ANSWERS Yes, provdied that the material is certified to meet all the requirements of an applicable material spec listed in 650 and it is approved by the buyer. (4.1.2) Shell plates for API 650 tanks are limited to what maximum thickness? - ANSWERS 1.75" (4.2.1.4) A tank is to be fabricated using ASTM A283 Grade C 'killed' material. The maximum thickness of the lower two course plates is 3/4". The tank is to be constructed in Las Vegas, NV. What Minimum Design Temperature could be used without impact testing? - ANSWERS 35F (3.4) and (Fig 4.2) An impact specimen is removed from a 1.25" thick ASTM A516 Grade 55 plate. Three impact tests are taken from the specimen. What average longitudinal impact value must the test meet? - ANSWERS 15ft-lb (Tab 4.5b) An AST is to be built in Mobile, AL. No other information is available. What design temperature would you use for this tank? - ANSWERS 25F (Fig 4.2) An AST's bottom plates are 1/4" thick. They are single-welded lap-jointed. The lap need not exceed how much? - ANSWERS 1" (5.1.3.5) The bottom course of a tank is made from 1" thick ASTM A283 Gr C plate. The second course of the tank is made from 3/4" thick plate. What is the minimum distance that a vertical seam of the top course must be offset from a vertical seam of the bottom course? - ANSWERS 5t, thickess of thicker course. (5*1) = 5" (5.1.5.1b) In a butt-welded bottom, three plate joints shall be at least how many inches from each other and from the tank shell? - ANSWERS 12" (5.1.5.4) Who specifies the design metal temperature, the design specific gravity, the corrosion allowance (if any) and the design wind velocity for the AST? - ANSWERS The purchaser (5.2.2) A tank is buit from ASTM A537M 1 (C-Mn-Si) normalized, quenched and tempered, killed fine-grain, reduced carbon and TMCP steel. The welding is done by an automatic process. The purchaser requires hardness testing of the welds. The tank diameter is 19.1M. How many (if any) hardness test(s) will be required for one circumferential weld? - ANSWERS One every 30m. (19.1*pi) = 60m, 2 hardness tests. (5.3.3.4) A new AST is built. How far should the bottom sketch plates project beyond the outside of the shell weld attaching the bottom to the shell plate? (These are not annular plates) - ANSWERS 2" (5.4.2) Annular bottom plates shall have a radial width that provides at least how many inches between the inside of the shell and any lap-welded joint in the reminder of the bottom? - ANSWERS 24" (5.5.2) An AST is to be designed using API650. The tank is to be 50ft diameter and 16ft high (two 8ft courses). No corrosion allowance is required. The stored liquid in the tank is a non-corrosive oil with a 0.90 specific gravity. The material is ASTM A285 C. What is the required thickness of the bottom shell course? - ANSWERS ? An AST that is 100 feet in diameter is required by API 650 to have a minimum nominal shell thickness of what (inches), even if the calculated thickness is less? - ANSWERS 1/4" (5.6.1.1) What is the minimum nominal width of shell plates (unless specified otherwise by the purchaser)? - ANSWERS 72" (5.6.1.2) What allowable design stress should be used when designing a new AST if it is constructed of ASTM A516 Gr70 plate? - ANSWERS 25, 300psi (Tab 5.2) The 1ft method for calculation of AST shell thickness shall not be used for tanks larger than how many feet in diameter? - ANSWERS 200ft (5.6.1.2) Openings in AST tank shells larger than required to accommodate what size flanged or threaded nozzle shall be reinforced? - ANSWERS To accomodate 2 NPS flanged or threaded nozzle (5.7.2.1) How far must a reinforced NPS 10 nozzle be placed form the centerline of a non-stress relieved 0.75" thick vertical buttweld seam in the bottom course of the tank? The nozzle is located 3ft up from the bottom weld. The reinforcing plate of the nozzle is 0.75" thick and it is welded with a 0.5" fillet weld around its periphery, and the nozzle welds have not been stress relieved. - ANSWERS The greater of 10" or 8W (weld). 8W=(8*0.5)=4". Use 10