Problems with safety valves on circulating water pipes
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It’s been a year since graduation, and I noticed an issue on site: on some of the circulating water pipes for heat exchangers, safety valves are installed either on the inlet pipes or on the return pipes. Are there any relevant installation rules for safety valves?
Installed on the return pipe, it prevents an increase in pressure caused by the heating of the cooling water. There is no need to consider the inlet pipe, as its pressure will not exceed that of the main inlet pipe, which is equipped with appropriate safety measures; therefore, there is no need to worry about the branch pipes as well.
If your water is used as a cooling medium, such as circulating cooling water, then a safety relief valve should be installed upstream of the return water shut-off valve. This is to prevent the temperature of the circulating water from rising to such an extent that some of the liquid turns into vapor, thereby maintaining normal pressure within the piping system. If water is used as the heating medium, such as in a reboiler, where it exists in the form of high-temperature steam, a safety valve must be installed at the inlet to protect the heat exchanger in case the steam pressure becomes too high.