The Definition Of Safety Valve
Safety valve is an important attachment of boiler, pressure vessels and other pressure equipment. Its acting reliability and performance have a direct effect to the safety of equipment and personal, and are closely related to energy-saving and environmental protection.
The safety valve includes discharge valve on broad sense, and from the management rules point, it can be directly installed in the steam boiler or pressure vessel, and its necessary conditions should be admitted by technical supervision departments, so called the safety valve on the narrowly. Other commonly known as discharge valve. Safety valve and the discharge valve are very similar in the structure and performance, both automatically discharge internal medium when exceeding the opening pressure, to ensure the safety of production equipment. Because of the similarity of this nature, we often confuse the two when using, in addition, some production facilities are also provided in the rules which can be chosen. Therefore, the difference between the two are often neglected. So there are many questions. If you want to make a more precise definition of the two valves, you may understand in accordance with first enunciated in the definition of "ASME Boiler and Pressure Vessel Code,":
1、Safety Valve is an automatic pressure relief device that drived by medium static pressure before the valve. It has the features of sudden open fall lift action, can be used for gas or steam occasions.
2、Relief Valves, also known as the relief valve, is an automatic pressure relief device drived by before valve medium static pressure. It opens in proportion with the increase of pressure exceeds opening force. It is mainly used for fluid occasions.
3、Safety relief valve, also known as the safety relief valve, is an automatic pressure relief device drived by before valve static pressure. According to the different using occasions, it can be used as the safety valve and the discharge valve. Japan, for example, they give few clear definition of the safety valve and the relief valve, generally used for large-scale energy storage such as a boiler pressure vessel safety device is called the safety valve, installed on the pipelines or other facilities is called as the discharge valve. However, if according to MITI's "thermal power technology standard," the important parts of device should be specified to use safety valves, such as the boiler, superheater, reheater, and so on. From this, the safety valve requires more reliability than the relief valve. Besides, from the Japanese Ministry of Labor of the high-pressure gas management rules, the Ministry of Transport and all levels of the ship association rules, the identification and regulations of safety emissions, we call the guarantee of the emissions as safety valve, while not guaranteed as the discharge valve. In our country, both fall lift and low lift are known as the safety valve.
