The definition and difference of safety valve and relief valve

Safety relief valve, also known as a driven by medium pressure safety relief valve pressure relief device automatically. According to the use of different occasions is applicable for a safety valve applies for a relief valve. In Japan, for example, to the safety valve and relief valve to make less well-defined, generally used for this kind of large boiler pressure vessel safety device called a safety valve, installed on the pipe or other facilities called discharge valve. If, however, according to Japan's miti 'thermal power technology standard' regulation, an important part of equipment safety, specify the use of safety valve, such as boiler, superheater, reheater, etc. And on the under side of the pressure relief valve need to connect with the boiler and turbine occasions, all need to install or safety valve discharge valve. So look, safety valve requirements more reliability than a relief valve. In addition, from the labor ministry of high pressure gas management rules,'s ministry, and various shipping association rules, the acknowledgment and provisions for security emissions, we call to ensure the emissions of a safety valve, and does not guarantee that emissions valve door called the discharge valve. At home no matter the rev type or micro and type are collectively referred to as the summary of a safety valve, safety valve is the boiler, pressure vessel and other pressure equipment on important safety accessories. Its operating reliability and performance is directly related to the equipment and personal safety, and closely related to energy saving and environmental protection. And some users in the selection and design department, always choose the wrong type. In this paper, the selection of safety valve for this analysis. Second, define the so-called broad sense including safety valve discharge valve, from the point of view of management rules, directly installed on the steam boiler or a pressure vessel, the necessary condition that must be recognized technical supervision department of the valve gate, in a narrow sense is called safety valve, other generally called the discharge valve. Safety valve and relief valve is very similar in structure and performance, when both are in more than opening pressure automatic discharge within the medium, to ensure the safety of the production plant. By similarities do exist in the essence, people when use, often to the confusion, in addition, some production device on the rules and regulations which all can choose. Therefore, the difference between the two often ignored. Thus appeared many problems. If you want to compare both make a clear definition, can be in accordance with the ASME boiler and pressure vessel code 'in the first article in this paper, the definition to understand: ( l） Safety valve is a kind of static pressure driven by valve before the medium pressure relief device automatically. Characterized by popping all open action. Used for gas or steam. ( 2) Discharge valve, also known as the overflow valve is a kind of static pressure driven by valve before the medium pressure relief device automatically. It increases with the increase of pressure more than open force in proportion to open it. It is mainly used for fluid.