1 Introduction  Komatsu Connecting Rod,Connecting Rod For Bearing,Connecting Rod For Engine,K20 Engine Connecting Rod Wuhu Hangtian Automobile Connecting Rod Co., Ltd , https://www.htconrod.com
The safety valve is a very important protective valve, widely used in various pressure vessels and pipeline systems. When the pressure in the pressurized system exceeds the specified value, it can automatically open and discharge excess medium into the atmosphere. In order to ensure the safe operation of pressure vessels and piping systems to prevent accidents, they can be automatically shut down when the system pressure drops back to working pressure or slightly lower than the working pressure. The reliability of the safety valve work is directly related to the safety of equipment and personnel, so it must be given attention.   
2, analysis and solutions  safety valve common cause of the malfunction
2.1 , safety valve valve leakage 
Under the normal working pressure of the equipment, leaks exceeding the permissible level occur at the sealing surfaces of the valve flap and the seat, and leakage of the safety valve will not only cause loss of the medium. In addition, the continuous leakage of the medium will also cause the hard seal material to be destroyed. However, the commonly used safety valve seal surface is a metal material to a metal material, although it strives to be smooth and smooth, but it should be done under the condition of medium pressure. It is very difficult to absolutely not leak. Therefore, for a safety valve where the working medium is steam, the seal performance is considered to be acceptable if the leak is not heard at the outlet end under the specified pressure value.
2.2, the relief valve body joint surface leakage 
Refers to the leakage phenomenon between the upper and lower valve body joint surface, resulting in the leakage of the main reasons are the following aspects: First, the joint surface of the bolt tight enough or tight, resulting in bad sealing joint surface.
The elimination method is to adjust the tightness of the bolts. When tightly tightening the bolts, it must be carried out diagonally. It is best to measure the gaps at the tight edges and tighten the bolts until the bolts are tight and make the gaps at the joint surfaces. Consistent. The second is that the toothed seal on the joint surface of the safety valve body does not meet the standard. For example, toothed seals have slight groove marks in the radial direction, poor parallelism, and defects such as sharp teeth or over-slopes can cause seal failure. So that the valve body surface leakage. The quality of a good spare part can be shut off during inspection and the use of a standard toothed seal can avoid this phenomenon. Thirdly, the flatness of the joint surface of the valve body of the safety valve is too bad or it is sealed by hard impurities, resulting in seal failure. For the leakage of the joint surface of the valve body due to the poor flatness of the joint surface of the valve body, the method of elimination is to disassemble the valve and regrind the joint surface until the quality standard is met. As the impurities are trapped and cause the seal to fail, carefully clean the joint surface during valve assembly to prevent impurities from falling.
2.3 . The main safety valve does not move after the impulse safety valve is actuated
This phenomenon is often referred to as the refusal of the main security door. The main security door refused to move is very serious for the boiler in operation, it is a major hidden danger of the equipment and seriously affects the safe operation of the equipment. Once the pressure in the pressure vessel and pipeline in operation exceeds the rated value, the main safety door Without action, equipment overpressure can easily cause equipment damage and major accidents.
Before analyzing the reasons why the main safety valve refused to move, first analyze the principle of the main safety valve. In addition, the moving parts of the valve of the safety valve are also stuck. This may be due to improper assembly, contamination of dirt and impurities or corrosion of parts; poor surface finish of the piston chamber surface, surface damage, defects such as grooves and hard spots. In this way, the frictional force fm between the moving member and the fixed member increases, and if other conditions do not change, f1 < f2+f3+fm, the main safety gate refuses to move .