Introduction to the hottest high pressure safety v

Introduction to high pressure safety valve

high pressure safety valve is a valve for safety protection. Its hoist is in a normally closed state under the action of external force. When the medium pressure in the equipment or pipeline rises and exceeds the specified value, it will automatically open. By discharging medium outside the system, the medium pressure in the pipeline or equipment will be prevented from exceeding the specified value. Safety valves are automatic valves, which are mainly used in boilers, pressure vessels and pipelines. The control pressure does not exceed the specified value, which plays an important role in protecting personal safety and equipment operation. According to the opening height of the safety valve disc, it can be divided into micro open safety valve and full open safety valve. The opening stroke height of the micro open safety valve is: 0.05d0 (minimum discharge throat diameter); The opening height of the full lift safety valve is 0.25d0 (minimum discharge throat diameter)

high pressure safety valves are divided into vertical hammer type, lever type, spring type and pilot type (pulse type) according to their structural forms; According to the structure of the valve body, it can be divided into closed type and non closed type. Closed safety valve means that the excluded medium will not leak out, and all of it will be discharged to the designated place along the outlet. It is generally used in toxic and corrosive media. For air and steam safety valves, non closed safety valves are mostly used. The selection of safety valve products should be determined according to the actual sealing pressure. For spring-loaded safety valves, springs with several working pressure levels within a nominal pressure (PN) range, in addition to indicating the model, name, medium and temperature of the safety valve, the sealing pressure of the valve body should also be indicated when ordering, otherwise the supply should be based on the maximum sealing pressure. The installation and maintenance of high-pressure safety valves should pay attention to the following matters: all kinds of safety valves should be installed vertically. There should be no resistance at the outlet of the high-pressure safety valve to avoid pressure. The safety valve should be specially tested before the overflow valve piston can be jacked or installed reversely, and its seal should be checked. The safety valve in use with poor loading stability shall be regularly inspected. The installation of safety valves shall meet the following requirements: (1) boilers with a rated evaporation capacity greater than 0.5 t/h, which is a compulsory national standard, shall be equipped with at least two safety valves: Boilers with a rated evaporation capacity less than or equal to 0.5t/h shall be equipped with at least one safety valve. Safety valves must be installed at the outlet of the separable economizer and the outlet of the steam superheater. (2) The high-pressure safety valve shall be installed vertically at the highest position of the boiler and header. Between the safety valve and the drum or header, no outlet pipe or valve for steam shall be installed. (3) The lever type safety valve shall be equipped with a device to prevent the weight from moving by itself and a guide frame to limit the derailment of the lever. The spring type safety valve shall be equipped with a lifting handle and a device to prevent the adjustment screw from being screwed casually. (4) For boilers with rated steam pressure less than or equal to 3.82MPa, the throat diameter of safety valve shall not be less than 25mm; for boilers with rated steam pressure greater than 3.82MPa, the throat diameter of safety valve shall not be less than 20mm. (5) The cross-sectional area of the connecting pipe between the high-pressure safety valve and the boiler shall not be less than the inlet cross-sectional area of the safety valve. If several safety valves are installed on a short pipe with high tensile and impact resistance directly connected to the drum, the passage cross-sectional area of the short pipe shall not be 1.25 times of the exhaust area of all safety valves. (6) Generally, the safety valve should be equipped with a steam exhaust pipe, which should lead directly to the safe place and have sufficient cross-sectional area to ensure smooth steam exhaust. The bottom of the exhaust pipe of the safety valve should be pretended to have a drain pipe connected to a safe place, and valves are not allowed to be installed on the exhaust pipe and drain pipe