Dear All,
When you have an heat exchanger shell&tube, normally you have to take into consideration a tube rupture scenario. Codes allow to avoid installation of PSV for tube rupture if the Low pressure side of the heat exchanger has a pressure design of at least 10/13 of the pressure design of the high pressure side.
In some engineering company designs I note that sometimes, when operating pressure of LP (low pressure) side is considerably lower than HP operating pressure, the pressure design of heat exchanger LP side is increased up to 10/13 of HP design pressure, but not the pressure design of connected systems upstream and downstream the heat exchangers.
Is there any reason for doing this? In my understanding this doesn't avoid the installation of a PSV for tube rupture to protect equipment connected to heat exchanger and, moreover, increases without apparent advantage the cost of an heat exchanger .
Thank you