【Daily Question】November 9 – Sealed flushing plan PLAN53 (First 80 participants + 2 additional points for those who get it right; 3–8 wealth points extra)

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This post was last edited by A Le on 2015-11-10 09:12. The Mechanical Section has introduced the \"Question of the Day\" feature, which not only helps to foster an active atmosphere for technical discussions and guide their direction but also provides users with financial rewards, enabling them to experience various cool features. 【Daily Question】In API682, the seal flushing PLAN 53 scheme is divided into A, B, and C, with the main difference lying in the methods used to apply pressure to the system. Among them, 53A is ( ), 53B is ( ), and 53C is ( ). A. Pressure is provided by a gas chamber accumulator. B. Pressure is provided by a piston-type accumulator. C. Pressure is provided by an external pressure source. Answer: CAB. Citing the analysis by [Desert Fish on Floor 3], the Plan53A, 53B, and 53C system solutions represent further improvements upon the original Plan53 system solution. API Solution 53A is applied to external seals that rely on a sealant system; through thermosiphon action, the pump efficiency ring design of the external seal (or other mechanisms) circulates the stirring heat and frictional heat generated by the external seal back to the sealant tank. After being cooled by water-cooled coils, this heat returns to the external seal chamber. Another function of this system is to lubricate the main sealing surface of the external seal. For the main seal, the direction of leakage is altered, with the sealant leaking from the main sealing surface into the internal seal chamber. The Plan53A system requires an external pressure source, usually nitrogen. It is recommended that the pressure of the isolation fluid be 1.5 Bar higher than that of the main sealing chamber. When the pressure in the main sealing chamber varies frequently or exceeds 500 Psi, a pressure regulator should be installed at the pressure source to ensure that the pressure of the isolation fluid remains 20–25 Psi higher than that of the main sealing chamber. In API Plan 53B, since pressure is applied directly using nitrogen, when the pressure exceeds a certain value, nitrogen penetrates into the sealing fluid, turning it into a gas-containing liquid. This not only affects the efficiency of the thermal cycling process, but more importantly, the gas-containing sealing fluid can cause gas to be released at the main sealing surface, leading to dry operation and thus failure of the seal. Therefore, there is a limit on the allowable operating pressure; usually, when the medium pressure is above 20 bar, the Plan 53A sealing system is not used instead the Plan 53B sealing system is employed, with a separately configured airbag-type accumulator providing the pressure source. The airbag prevents contact between nitrogen and the sealing fluid. Similarly, since there is no pressure source higher than that of the medium available on-site, the pressure source for the sealing fluid is provided by the airbag-type accumulator. Plan53B 5: air-bag type accumulator; API Plan53C. Due to the high pressure and significant fluctuations in the medium within the inner sealing chamber, the pressure of the secondary protective sealing fluid on the outside must be set at the highest level of these fluctuations, which results in the outer seal operating under high-pressure conditions on a regular basis. To address this issue, the Plan53C sealing fluid system is used, with a differential pressure cylinder providing the pressure for the sealing fluid at a ratio of 1:1.1. The larger cylinder of this differential pressure cylinder is connected to the main sealing chamber, while the smaller cylinder (with a piston rod) is connected to the sealing fluid. The pressure of the sealing fluid increases in proportion to the pressure in the main sealing chamber, by a factor of 1:1.1. Plan53C is suitable for applications involving high pressures and significant pressure variations. Requirements and tips for answering questions: Please reply with the answer you believe to be correct. If you provide a detailed explanation or analysis of the question or answer, an additional reward will be given. Extra rewards will be awarded if your answer is correct and your explanation is thorough and accurate. Feel free to answer the questions. Please note: We will close this thread after 24 hours, and at that time we will announce the best reply (the best assistance), as well as the answer and explanation. Do not submit answers repeatedly. 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