The safe discharge capacity of a pressure vessel refers to the amount of gas that must be released per unit time in order to ensure that the pressure of the pressure vessel does not rise again when the pressure vessel is overpressured.
The displacement of the safety valve refers to the discharge per unit time under the discharge pressure when the safety valve is fully open.
For boilers, the total displacement of safety valves must be greater than the maximum continuous evaporation of the boiler, and after all safety valves on the drum and superheater are opened, the steam pressure in the drum must not exceed 1.1 times the design pressure. For pressure vessels, it is required that the displacement of the safety valve must be at least equal to the safe discharge capacity of the pressure vessel.
The selection of safety valve should consider the following aspects:
(1) What type of safety valve is selected for the structural form mainly depends on the technological conditions of the equipment and the characteristics of the working medium. In general, most boilers and pressure vessels use spring safety valves. If the working medium of the container is toxic, flammable and explosive, a closed safety valve is selected. Boilers and high-pressure vessels, as well as medium and low-pressure vessels with large safety relief and low wall thickness, are best to use full-open safety valves.
(2) Pressure range The safety valve is designed and manufactured according to the nominal pressure standard series, and each safety valve has a certain working pressure range. When selecting, the appropriate safety valve should be selected according to the maximum allowable working pressure of the boiler and pressure vessel.
(3) The discharge volume of the safety valve selected must be greater than the safety discharge volume of the equipment, so as to ensure that when the boiler or pressure vessel is overpressured, a part of the medium can be discharged in time when the safety valve is opened, so as to avoid the pressure inside the device from continuing to rise.
The safe discharge capacity of a pressure vessel refers to the amount of gas that must be released per unit time in order to ensure that the pressure of the pressure vessel does not rise again when the pressure vessel is overpressured.
The displacement of the safety valve refers to the discharge per unit time under the discharge pressure when the safety valve is fully open.
For boilers, the total displacement of safety valves must be greater than the maximum continuous evaporation of the boiler, and after all safety valves on the drum and superheater are opened, the steam pressure in the drum must not exceed 1.1 times the design pressure. For pressure vessels, it is required that the displacement of the safety valve must be at least equal to the safe discharge capacity of the pressure vessel.
The selection of safety valve should consider the following aspects:
(1) What type of safety valve is selected for the structural form mainly depends on the technological conditions of the equipment and the characteristics of the working medium. In general, most boilers and pressure vessels use spring safety valves. If the working medium of the container is toxic, flammable and explosive, a closed safety valve is selected. Boilers and high-pressure vessels, as well as medium and low-pressure vessels with large safety relief and low wall thickness, are best to use full-open safety valves.
(2) Pressure range The safety valve is designed and manufactured according to the nominal pressure standard series, and each safety valve has a certain working pressure range. When selecting, the appropriate safety valve should be selected according to the maximum allowable working pressure of the boiler and pressure vessel.
(3) The discharge volume of the safety valve selected must be greater than the safety discharge volume of the equipment, so as to ensure that when the boiler or pressure vessel is overpressured, a part of the medium can be discharged in time when the safety valve is opened, so as to avoid the pressure inside the device from continuing to rise.