Sealing surface machining of poor quality, mainly in the sealing surface cracks, porosity and other defects clip ballast, welding and heat treatment specifications due to improper selection and operation of welding and heat treatment process caused by bad sealing surface hardness is too high or too, is due to wrong selection or improper heat treatment, the sealing surface uneven hardness, corrosion intolerance, mainly due to the welding process will come on top of the underlying metal blown, dilute the alloy composition caused by the sealing surface. Of course, there is also a design problem. Improper selection and damage caused by adverse operating. Mainly by the working conditions in the absence of selection of valve, the shut-off valve when the throttle use, leading to closure than the pressure is too large and too close or shut lax, so that the sealing surface by erosion and wear. Erosion of the medium, which is the medium flowing on the sealing surface abrasion, erosion, cavitation results. When the media at a certain speed, medium fine floating gate valve sealing surface collision to cause local damage trench clear shot valve, direct high-speed flow of medium sealing surface erosion to cause local damage, mixed media and local vaporization , bubbles bursting impact surface dark bar valve sealing surface, causing local damage. Erosion corrosion combined with chemical media outlets alternation gate, strongly sealing surface erosion. Mechanical damage, the sealing surface in the opening and closing over we will produce scratches, bumps, crushing and other damage. Between the two sealing surfaces, the role of high temperature and pressure generation atomic mutual penetration, resulting in blocking phenomenon. When the two mutually movable sealing surface, easy to pull tear adhesions. The higher the surface roughness of the sealing surface, this phenomenon is more likely to occur. The valve is closed, the valve flap in the back seat and the crushing process will bruise the sealing surface, the sealing surface of the local wear or indentation. Clamp valve, gate valve, England electromechanical provided by City Electrical Equipment Co., Ltd. of England. England City Electrical Equipment Co., Ltd. (www.gdyinglun.com) strong, credible, hydraulic machinery and components industry in Dongguan, Guangdong has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead England into the brilliant electromechanical and you work for a better future!