After the safety valve jumps, the pressure control valve should be opened immediately to pay the line or vent line to reduce the pressure to the normal control range, and then check whether the safety valve can be automatically reset, if not reset, then close the safety valve hand valve, remove the safety valve for repair, and then install it again after re-pressurization.
Check whether the jump back to the seat intact, that is to say, after the jump the safety valve is still as good as the original seal, if there is no leakage and other adverse conditions do not need to deliberately deal with. If there is no leakage, no special treatment is needed. If there is leakage, the safety valve calibration department should be asked to repair and calibrate the valve again. If your safety valve jumps frequently, it means that your safety valve calibration pressure may not be correct, and must be sent to the calibration department to recalibrate.
Expanded Information
Safety valve
Safety valves are special valves that are normally closed when the pressure of the medium in the equipment or pipeline rises above a specified value, and prevent the pressure of the medium in the pipeline or equipment from exceeding the specified value by discharging the medium to the outside of the system. Safety valve belongs to the automatic valve category, mainly used in boilers, pressure vessels and pipelines, control pressure does not exceed the prescribed value, for personal safety and equipment operation plays an important role in protection. Note that the safety valve must undergo a pressure test before use.
Development
Safety valve is a special branch of the valve family, it is special because it is different from other valves only play a role in switching, and more importantly, play a role in protecting the safety of equipment. With the rapid development of China's economic construction, with pressure manipulation of equipment projects more and more. In view of the need for equipment pressure relief, safety valves play a vital role in the process of protecting equipment.
As of 2013 all types of safety valve manufacturers and traders have more than 700, daily trading inquiries reached more than 200, the supply and demand for safety valves market heated up significantly. Through the preliminary analysis of the first quarter data, the demand for safety valves to be twenty percentage points higher.
Safety valves are important safety accessories for boilers, pressure vessels and other pressurized equipment. Safety valve (also known as pressure relief valve) is based on the working pressure of the pressure system (operating temperature) automatically open and close, generally installed in the closed system of equipment or pipeline to protect the system safety. When the pressure or temperature in the equipment or pipeline exceeds the set pressure of the safety valve, it automatically opens to relieve pressure or reduce temperature to ensure that the pressure (temperature) of the medium in the equipment and pipeline under the set pressure (temperature), to protect the normal operation of the equipment and pipeline to prevent accidents and reduce losses. Safety valves are widely used in: steam boilers, liquefied petroleum gas
Oil and gas car tanker or liquefied petroleum gas railroad tanker, oil extraction wells, steam power generation equipment, high-pressure bypass, pressure piping, pressure vessels and so on. Safety valves are generally divided into spring-loaded safety valves and lever-loaded safety valves, pulse safety valves, of which the spring-loaded safety valves are most commonly used; according to the connection method is divided into threaded safety valves and flange safety valves. Safety valve caliber are generally not large, commonly used in DN15mm-DN80mm, more than 150mm are generally known as large caliber safety valves. 2013 safety valve industry market size, which has been an indisputable fact.
China can qualify the production of safety valves is not a large number of enterprises, because the safety valve is a special equipment industry, the State Administration of Quality Supervision in the application of qualification review is more stringent, and the huge demand for safety valves market, undoubtedly, to the qualified production of safety valves for these enterprises to bring more opportunities for wealth.
Main role
Safety valves play a safety protection role in the system. When the system pressure exceeds the specified value, the safety valve opens and discharges a part of the gas and fluid in the system into the atmosphere outside the pipeline, so that the system pressure does not exceed the permissible value, so as to ensure that the system is not overpressurized and accidents occur.
Technical Terms
Nominal Pressure: Nominal pressure: the maximum permissible pressure of the safety valve at room temperature, high temperature equipment with safety valves should not be considered at high temperatures under the reduction of the permissible stress of the material. Safety valves are designed and manufactured according to the nominal pressure standard.
Opening pressure: also called rated pressure or set pressure, is the safety valve valve flap in the operating conditions began to rise when the inlet pressure, in the pressure, the beginning of the measurable height of the opening, the medium is a continuous discharge can be perceived by the visual or auditory state.
Discharge pressure: the valve flap reaches the prescribed opening height of the inlet pressure. The upper limit of the discharge pressure is subject to the requirements of the relevant national standards or norms.
Over pressure: the difference between the discharge pressure and the opening pressure, usually expressed as a percentage of the opening pressure.
Seat pressure: discharge valve flap re-contact with the valve seat, that is, the opening height becomes zero when the inlet pressure.
Differential opening and closing pressure: the difference between the opening pressure and the return pressure, usually expressed as a percentage of the return pressure and the opening pressure, only when the opening pressure is very low using the difference between the two pressures to indicate.
Back pressure: the pressure at the outlet of the safety valve.
Rated discharge pressure: the upper limit of the standard discharge pressure.
Sealing test pressure: the inlet pressure for sealing test, at which the leakage rate through the sealing surface of the closing member is measured.
Opening height: the actual lift of the valve flap from the closed position.
Runner area: the minimum cross-sectional area of the runner between the inlet end of the valve flap and the sealing surface of the closing member, used to calculate the theoretical displacement without any resistance.
Runner diameter: the diameter corresponding to the area used for the runner.
Curtain area: when the valve valve above the seat, between the sealing surface of the cylindrical or conical surface area of the channel.
Vent area: the minimum cross-sectional area of the fluid passage when the valve is vented. For full-opening safety valve, the discharge area is equal to the area of the flow channel; for micro-opening safety valve, the discharge area is equal to the curtain area.
Theoretical displacement: is the cross-sectional area of the flow path and the safety valve flow path area is equal to the calculated displacement of the ideal nozzle.
Discharge coefficient: the ratio of the actual displacement to the theoretical displacement.
Rated displacement coefficient: displacement coefficient and the product of the reduction factor (take 0.9).
Rated displacement: refers to the actual displacement of that part of the safety valve allowed as a benchmark for the application.
Equivalent calculated displacement: refers to the pressure, temperature, media properties and other conditions and rated displacement of the same conditions, the calculated displacement of the safety valve.
Frequent bouncing: safety valve valve flap quickly and abnormally back and forth movement, in the movement of the valve flap contact valve seat.
Fluttering: safety valve flap rapid and abnormal back and forth movement, in the movement of the valve flap does not contact the valve seat.
Valve development trend
China's valve industry chain is numerous, but not a valve power. Overall look China has entered the ranks of the world's major valve country, but from the product quality point of view of China's valve power still has a long way to go. The industry's low concentration of production, high-end products matching the low R & D capacity of the valve, the valve industry, such as the low level of manufacturing technology still exists, the import and export trade deficit is expanding.
The next few years will be the valve industry's high-speed shock period, a direct consequence of this high-speed shock is to lead to the expansion of the trend of polarization in the valve cabinet brand camp. Really able to survive in the market valve business is definitely not so much. But this high-speed shock of the valve industry will bring great opportunities, the results of the shock will make the market operation more rational.
The road to localization of high-end valves is exceptionally "bumpy". The purpose of the basic parts has become a constraint on China's manufacturing industry to the high-end development of the short board, during the 12th Five-Year Plan, the government will continue to increase the localization of high-end equipment parts and components. Here we select the "implementation program" mentioned in several key development industries representative of the valve for import substitution feasibility analysis (such as petroleum, power plants, metallurgy, machinery, electronics, mining, chemical industry, building materials, electric power, energy, sewage treatment, etc.). From the analysis we can see that the sub-sector valve import substitution feasibility varies greatly, high-end valves urgently need more policy guidance and scientific research support.
Valve industry in the development of the national economy, as an important part of the preparation for manufacturing, play a very important role. Because of China's domestic valve manufacturing level compared with the international advanced level there is still a gap, a lot of high parameters, high temperature and high pressure, high pounds of key valves have been dependent on imports.
In order to promote the localization of valves, in the State Council issued a "number of opinions on accelerating the revitalization of the equipment manufacturing industry", the relevant state departments in accordance with the requirements made by the state of the localization of major equipment, has made a series of major deployments and led by the National Development and Reform Commission, the China Machinery Industry Federation and the China General Machinery Industry Association, the deployment of the development of the relevant areas of major equipment, the valve Localization of the program, and many times with the relevant departments to coordinate, and now the localization of valves in the domestic valve industry has formed a **** knowledge.
Actively adopt international standards for product design; absorption of foreign excellent design structure (including patented technology); product testing, performance testing in strict accordance with international standards; absorption of foreign advanced production process experience and attention to the research and application of new materials; to clarify the imported high-parameter valves, such as the technical parameters and conditions of the valve products is to speed up the process of localization to promote the continuous updating of the valve products, the only way to fully realize the localization of valves. The only way to fully realize the localization of the valve.
With the accelerated pace of restructuring of the valve industry, the future of the industry will be the safety of valve product quality and product brand competition between the products to high-tech, high parameters, strong corrosion resistance, high life direction, only through continuous technological innovation, the development of new products, technological innovation, in order to gradually improve the technical level of products to meet the domestic device supporting the full realization of the localization of the valve. China's valve manufacturing industry in the huge demand for environment, will certainly show better prospects for development.
Source of reference: Baidu Encyclopedia-Safety Valve