tailieunhanh - Process Engineering Equipment Handbook Episode 3 Part 7

Tham khảo tài liệu 'process engineering equipment handbook episode 3 part 7', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Tanks T-29 TABLE T-1 Overview of Inventory Uncertainties Level Inventory Servo Radar HIMS HTG m ft Mass . . Mass Mass . 20 66 10 33 2 Inventory uncertainties in TABLE T-2 Overview of Batch Transfer Uncertainties Transfer Level Servo Radar HIMS HTG m ft Mass GSV GSV Mass Mass GSV 20-18 66-60 4-2 20-26 Batch transfer uncertainties in NOTE For level-based systems servo radar the density is obtained from the laboratory analysis of a grab sample the uncertainty is assumed to be percent. independent approval institute. Well-known institutes are PTB Germany Factory Mutual Research USA SAA Australia JIS Japan and CSA Canada . The better tank-gauging instruments do not just meet the safety standards but exceed them by anticipating future safety requirements as well. Such requirements include the exclusion of aluminum inside storage tanks zone 0 the limitation of the kinetic energy of moving parts of a gauge to values far less than could cause ignition. Lightning and tank gauging. Lightning can cause hazardous situations and measures should be taken to protect the tank installation and tank-gauging system against these hazards. Modern tank-gauging systems contain many electronic circuits. Their position on top of storage tanks makes this equipment more vulnerable to lightning damage than any other type of industrial equipment. Today s communication systems linking all field equipment via one network increase the probability of possible damage to the equipment as the networks spread over increasingly larger areas. With high reliability and availability one of the prime requirements of modern tank-gauging equipment there is a need for well-designed field-proven lightning protection methods. Figure T-19 shows a tank gauge under high voltage test. In tank farms .