If the leakage between the valve flap and the valve seat of the safety valve exceeds the rated range, the medium will be lost and the sealing material will be damaged. — Under normal circumstances, the sealing surface of the safety valve is mainly composed of metal materials, and it is made as smooth and flat as possible, but in the case of secondary extrusion with pressure, it is unlikely that it will be completely sealed without leaking of. Therefore, in the rated pressure environment, the safety valve using steam as the medium can be detected by relying only on naked eyes and ears. There are two main reasons for valve leakage:

       Dirt and debris appear on the sealing surface, and the original sealed plane is blocked to separate the gap between the valve core and the valve seat. This causes the valve to leak. Solving this type of problem is usually the dirt on the sealing surface. When the boiler is temporarily decommissioned for maintenance, it is necessary to perform a run test on the safety door, and if there is a leak, it should be repaired as a whole. -The interval between normal running runs is 20 minutes after full cooling.

       Damage to the sealing surface. There are many reasons, such as: the sealing material is unqualified. After years of use of the safety valve, the strength of the sealing surface is easily weakened due to continuous switching on and over maintenance and other reasons, resulting in weakened sealing ability. Suggested measures to solve this problem are to flatten the original sealing surface, and perform secondary processing welding according to the original drawings to enhance the hardness and strength of the surface, and pay attention to the surface damage, and must not be careless.

       Overhaul quality. Due to the poor level of maintenance, the valve core and valve seat cannot reach a certain level in the grinding process. The solution is to use grinding or even turning to repair the sealing surface as much as possible depending on the severity of the damage.

       Improper assembly or incorrect size of parts. During the entire assembly work, the valve core and the valve seat are not completely aligned, or a serious light transmission problem occurs on the joint surface. It may also be that the seal between the valve core and the valve seat is too loose and it is difficult to truly seal. The solution is to strictly check the length, thickness, and distribution of the gaps next to the valve core, and to ensure that the valve core cannot be lifted in the gap between various parts, and the width of the sealing surface is appropriately reduced to seal according to the data on the drawing.