停机主要是由机械密封的毛病形成的。毛病的表现大都是走漏，走漏缘由有以下几种：
　　1、动静环密封面的走漏，缘由主要有：端面平面度，粗糙度未到达请求，或外表有划伤;端面间有颗粒物质，形成两端面不能同样运转;装置不到位，方式不正确。
　　2、补偿环密封圈走漏，缘由主要有：压盖变形，预紧力不平均;装置不正确;密封圈质量不契合规范;密封圈选型不对。
　　实践运用效果标明，密封元件毛病最多的部位是动，静环的端面，渣浆泵机封动，静环端面呈现龟裂是常见的毛病现象，主要缘由有：
　　1、装置时密封面间隙过大，冲洗液来不及带走摩擦副产生的热量;冲洗液从密封面间隙中漏走，形成端面过热而损坏。
　　2、液体介质汽化收缩，使两端面受汽化收缩力而分开，当两密封面用力贴合时，毁坏光滑膜从而形成端面外表过热。
　　3、液体介质光滑性较差，加之操作压力过载，两密封面跟踪转动不同步。例如高转速泵转速为20445r/min，密封面中心直径为7cm，泵运转后其线速度高达75 m/s，当有一个密封面滞后不能跟踪旋转，瞬时高温形成密封面损坏。
　　4、密封冲洗液孔板或过滤网梗塞，形成水量缺乏，使机封毛病。
　　另外，密封面外表滑沟，端面贴合时呈现缺口招致密封元件毛病，主要缘由有：
　　1、液体介质不清洁，有微小质硬的颗粒，以很高的速度滑人密封面，将端面外表划伤而毛病。
　　2、机泵传动件同轴度差，泵开启后每转一周端面被晃动摩擦一次，动环运转轨迹不同心，形成端面汽化，过热磨损。
　　3、液体介质水力特性的频繁发作惹起泵组振动，形成密封面错位而毛病。
　　液体介质对密封元件的腐蚀，应力集中，软硬资料配合，冲蚀，辅助密封0形环，V形环，凹形环与液体介质不相容，变形等都会形成机械密封表面损坏毛病，所以对其损坏方式要综合剖析，找出基本缘由，保证机械密封长时间运转。

Shutdown is mainly caused by mechanical seal defects. The performance of the problem is leakage, leakage reasons have the following several: 1, Dynamic and static ring sealing surface leakage, the main reasons are: End flatness, roughness did not meet the requirements, or the appearance of scratches; between the end surface particulate matter, the two ends can not operate equally; the device is not in place, the way is not correct. 2. Leakage of the sealing ring of compensation ring, the main reasons are: the deformation of gland, uneven pre-tightening force, incorrect device, the quality of the sealing ring does not conform to the specifications, the wrong type of sealing ring. The practical application results show that the most defective parts of the sealing elements are the end faces of the moving and stationary rings, the Slurry Pump Seals, and the crack of the end faces of the stationary rings is a common fault phenomenon. The main reasons are as follows: 1, the heat produced by the friction pair can not be carried away by the flushing fluid; the flushing fluid leaks from the gap of the sealing surface, resulting in overheating of the end surface and damage. 2, the liquid medium vaporized shrinkage, so that the two end surface by vaporized shrinkage force and separate, when the two sealing surface force-fit, destroy the smooth film to form end surface overheating. 3, the liquid medium smoothness is poor, in addition to the operation pressure overload, two sealing surface tracking rotation is not synchronized. For example, the speed of high speed pump is 20445r/min, the diameter of seal surface center is 7cm, the linear speed of pump is as high as 75m/s after running, when there is a seal surface can not follow the rotation, the seal surface is damaged by the instantaneous high temperature. 4, sealing washing liquid orifice plate or filter screen obstruction, forming a lack of water, so that the machine seal. In addition, the surface of the seal groove, the end of the joint when the gap caused by sealing elements defects, the main reasons are: 1, the liquid medium is not clean, there are tiny hard particles, with a very high speed sliding seal surface, scratch the surface of the end surface. 2. Poor coaxiality of the driving parts of the pump, the end face is shaken and rubbed once every turn after the pump is turned on, and the running track of the moving ring is different, resulting in end face vaporization and over-heat wear. 3, the frequent occurrence of the hydraulic characteristics of the liquid medium caused the pump vibration, the formation of seal surface dislocation and fault. The corrosion of liquid medium to sealing elements, stress concentration, soft and hard data matching, erosion, auxiliary sealing 0-ring, v-ring, concave ring and liquid medium are incompatible, deformation, etc. , therefore, the damage mode should be comprehensively analyzed to find out the basic reasons to ensure the long-term operation of mechanical seals.