The boiler safety valve is one of the most important safety accessories to ensure the safe operation of the boiler. Whether it can be opened accurately and reliably is of great significance to the safe operation of the boiler. In this paper, the author analyzes and discusses the common faults of the boiler safety valve in the daily operation and the related elimination methods. This article by the Shanghai Five Valve Manufacturing Co., Ltd. reproduced share, Shanghai Wuyue is a professional safety valve manufacturers, the main production of various types of spring-loaded safety valve, pilot-operated safety valve ?, and for the use of units to provide related products for technical support. As a valve with an important protective function, safety valves are used in a wide range of pressure vessels and piping systems in a wide range of applications. When pressure vessels (systems) reach the upper limit of their pressure tolerance, they are automatically activated , Discharge excess media out of the pressure vessel (system), and automatically close it after it has been drained, thereby ensuring that the pressure vessel can operate within safe and reliable pressure limits to avoid major accidents. The normal operation of the safety valve not only relates to the normal safe use of pressure vessels such as boilers but also relates directly to the safety of people's lives and property. Therefore, the common failures of safety valves of boilers must be given high priority and solved promptly. In the following, the author of the boiler safety valve in the daily operation of the common failures and related troubleshooting methods were analyzed and discussed 1. Safety valve leaked Leakage of the valve is one of the most common faults in the safety valve of the boiler. It mainly refers to the leakage of the valve flap and the seat seal exceeding the allowable level under the normal working pressure of the boiler. Causes of failure and its solution: ①dirt falls on the sealing surface. Can use the lift wrench to open the valve a few times, the dirt washed away; ② sealing surface damage. Should be based on the degree of injury, grinding or turning grinding method to be repaired. Repair should ensure that the seal surface roughness, the finish should not be less than 10; ③ due to improper assembly or pipe load and other reasons, so that parts of the concentricity damage. Should be reassembled or ruled out pipeline additional load; ④ valve opening pressure and equipment normal pressure is too close, as the sealing surface is lower than the pressure. When the valve is subject to shock or media pressure fluctuations, the more prone to leakage. Should be based on equipment strength conditions on the opening pressure to make appropriate adjustments; ⑤ spring relaxation to reduce the setting pressure and cause valve leakage. May be due to heat or corrosion caused by other reasons, should be taken for spring, and even for the valve and other measures. Ruoyin due to improper regulation caused by the need to properly tighten the adjustment screw can be. 2. Safety valve back seat pressure is too low Causes of failure and its solution: Low seat back pressure will cause a large number of media time-out emissions, resulting in unnecessary energy loss, the formation of the spring pulse relief valve on the steam discharge, this form of impulse safety valve to open, the media continue to discharge, vibration Safety valve body, or the momentum before and after the relief valve due to the main relief valve medium discharge is not enough and continue to rise, so the pulse tube of steam along the drum in the gas collection header continue to impulse safety valve to maintain the impulse safety valve action. On the other hand due to this type of impulse safety valve actuation impulse valve sealing surface. To the reorganization of the formation of kinetic energy pressure zone, the valve core elevation, so as to achieve the impulse safety valve to continue emissions, the greater the steam emissions, the role of the spool on the safety of the thrust on the greater the smaller the impulse safety valve easy to back . At this point to eliminate this failure is to throttle the small, so that out of the flow of the relief valve medium flow rate decreases, reducing the pressure in the kinetic pressure area, so that the impulse safety valve back seat. The second factor that causes the seat back pressure is low is the fit clearance between the valve core and the guide sleeve is not suitable, with the gap is small, to the impulse safety valve Kai seat in this area instantly throttling to form a high kinetic energy pressure zone, the spool Raise, delay back seat time, eliminate this failure is to carefully check the spool also guide the size of the various parts of the sleeve, with the gap is too small, reducing the valve cover straight to the valve cap or valve cap diameter or increase the flap and guide Set between the radial gap, to increase the flow area of ​​the site, so that the steam flow path will not shunt, leaving the local pressure to form a high kinetic energy pressure zone. 3 valve body surface leakage Leakage of the valve body surface mainly refers to leakage between the upper and lower valve body surface leakage. Causes of failure and its solution: First, the binding surface of the bolt tightness or tight side, resulting in poor sealing surface. Elimination method is to adjust the bolt tightness, the tight bolt must be diagonally tight manner, it is best to measure the gap around the edge of the tight bolt will not move so far, and to make the gap around the junction Consistent. Second, the valve body with the tooth surface seal does not meet the standards. For example, the radial seal groove slightly grooved, poor parallelism, tip too sharp or over-the-slope and other defects can cause seal failure. So that the valve body surface leakage. In the maintenance of good spare parts quality, the use of standard toothed gaskets can avoid this phenomenon. Third, the flatness of the valve body with poor or hard padded impurities caused by seal failure. The valve body due to the flatness of the joint surface caused by poor bonding surface leakage, the elimination of the valve is to disintegrate the valve to re-ground the joint until the quality standards. As a result of impurities caused by gasket failure seal in the valve assembly carefully clean the surface to avoid impurities fall into. 4. Safety valve delayed back seat Mainly for the momentum relief valve seat back after the main safety valve delay back seat too long. Causes of failure and its solution: The main reason for this failure are the following two aspects. On the one hand, the main relief valve piston chamber leakage volume, although the impulse safety valve back seat, but there is still pressure in the pipeline and the piston chamber of the steam is still high, pushing the piston downward force is still large, So cause the main safety valve back seat slowly. The way to eliminate this kind of failure is mainly solved by opening the large throttle and increasing the throttle diameter. The large throttle opening and the increase of throttle make the steam left in the pulse tube to be drained rapidly , Thereby reducing the pressure inside the piston, so that the downward thrust on the piston quickly reduce the thrust in the steam turbine steam accumulator up thrust and the main safety valve spring pull up rapidly under its own back seat. On the other hand, the main safety valve is the friction between the moving parts and fixed parts can also cause the main relief valve seat back slowly, to solve this problem is the main safety valve moving parts and fixed parts with the gap Console standard range. 5. Safety valve flutter Safety valve in the discharge process of jitter phenomenon, called the safety valve flutter, flutter phenomenon can easily lead to metal fatigue, the safety valve to reduce the mechanical properties, causing serious equipment problems. Causes of failure and its solution: Flutter occurs mainly in the following aspects: On the one hand the improper use of the valve, the selection of the valve discharge capacity is too large, the elimination method should be selected valve rated displacement as close as possible to the necessary emissions of equipment. On the other hand is due to the inlet pipe diameter is too small, smaller than the inlet diameter of the valve, or inlet pipe resistance is too large, the elimination of the valve is installed, the inlet pipe diameter not less than the inlet diameter of the valve or reduce the import pipe Resistance, excessive discharge pipe resistance, resulting in excessive back pressure discharge is also a factor that causes the valve flutter can be solved by reducing the resistance of the exhaust pipe. Conclusion: The boiler safety valve is one of the most important safety accessories to ensure the safe operation of the boiler. Whether it can be opened accurately and reliably is of great significance to the safe operation of the boiler. In this paper, the safety valve leaks from the safety valve back seat pressure is too low, the valve body surface leakage, the safety valve delay back seat, flutter and other aspects of the safety valve to discuss the boiler safety valve common faults and proposed solutions .