Calculate the density, as well as temperature and pressure under the discharge conditions of the safety valve
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Excuse me, as shown in the diagram, what values should be entered for density, as well as temperature and pressure under the relief condition for the safety valve? 1. Is the density of the medium under relief condition determined based on operating pressure, set pressure, or design pressure? Is P gauge pressure or absolute pressure – that is, does 0.1 need to be added, and should overpressure be taken into account by using 1.1 times the design pressure? 2. Is the unloading temperature the ambient temperature or the design temperature? 3. Is the pressure on the outlet side 0.1 MPA at atmospheric pressure?
The discharge pressure should refer to the operating pressure; loosely speaking, it can be replaced by the set pressure. If pressure is not specified, it is generally considered as gauge pressure. The discharge temperature is the temperature of the medium; either the maximum operating temperature or the design temperature can be used, unless it falls exactly at a boundary condition, in which case a specific assessment is required. If the outlet pressure relief side is connected to the atmosphere, the atmospheric pressure applies; if a pipe is used for connection, the resistance of that pipe must be taken into account. If it is connected to another container, the operating pressure of that container applies.
The pressure for release, in accordance with GB150, should be determined by the design pressure, and it should be absolute pressure. The discharge temperature should be dependent on the medium; in the case of liquefied gases, it should be related to the release pressure. The pressure on the outlet side depends on whether there is backpressure; if not, it is atmospheric pressure.
Agree with the person above! If the medium is a liquefied gas, the temperature of the medium at the discharge pressure must be taken into account; an increase in temperature corresponds to an increase in pressure! Temperature and pressure are related to each other! Rather than just the design temperature.
The set pressure is mostly close to the design pressure.
The setting pressure, in accordance with GB150, should be determined based on the design pressure; it is generally slightly less than the design pressure, while for applications requiring airtightness, it must be equal to or greater than the design pressure.