Why are the two safety valves on the SHELL drum located on the same side?
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Why are the two safety valves on the SHELL drum located on the same side?
The tripping pressures of the two safety valves are different. For safety reasons, two safety valves are set.
According to the American standards, two PSVs must be installed. From the gasifier control principle, the two PSVs should be evenly distributed on both sides of the steam drum. From the equipment layout of the steam drum itself, it is okay if they are placed on the same side. If the PSV operates on the same side, the liquid level deviation will increase, and 13XV0049 will be interlocked to open. Once 0049 is opened, it is not important how to arrange it. Moreover, Sinopec's SCGP devices have all canceled XV0049 and replaced it with a two-way flow meter, so there is no such problem.
According to the regulations of the American Society of Mechanical Engineers, setting two is mainly to consider the discharge flux. The different setting values of the two are to reduce the vibration generated during discharge.
Another consideration is that if the jump value of one safety valve deviates, the other one can still play a safety role.