At present, the safety valves mass-produced in the market are divided into two main categories: spring-loaded and lever-loaded. In addition to these, there are a number of other types of safety valves, such as impulse-type, pilot-type, safety switching valves, safety relief valves, and static-weight type.
The operating principle of spring-loaded safety valves depends mainly on the force of the spring. These safety valves are further divided into two types: closed and unclosed. For flammable, explosive or toxic media, we usually choose closed safety valves to ensure safety. For mediums such as steam or inert gases, unenclosed safety valves are a good choice. In spring-loaded safety valves, some of them are also equipped with wrenches, the main purpose of which is to check the flexibility of the valve flap, and can also be used as a manual pressure relief in case of emergency.
Lever-type safety valves, on the other hand, rely on the force of a lever and weight to operate. However, its large size often limits its application. In high temperature environments, we usually choose safety valves with heat sinks to ensure their proper operation.
An important parameter of safety valves is the discharge volume, which mainly depends on the caliber of the valve seat and the opening height of the valve flap. According to the different opening heights, safety valves are divided into two types: micro-opening type and full-opening type. Micro-opening safety valve flap opening height for the seat throat diameter of 1/40 to 1/20, while the full-opening safety valve flap opening height for the seat throat diameter of 1/4. These different designs are to adapt to different working conditions and media characteristics.
We hope that the above can help you better understand the types and working principle of safety valves.