机械密封检修规程

Maintenance rules for mechanical seals

要掌握机械密封检修与维护，首先要知道机械密封的工作原理。机械密封是由两块密封元件（静环与动环）垂直于轴的、光洁而平直的表面相互贴合，并作相对转动而构成的密封装置。它是靠密封介质的压力在旋转的动环合静环的接触表面（端面）上产生适当的压紧力，使这两个端面紧密结合，端面间维持一层极薄的液体膜而达到密封目的的。这层液体膜具有液体动压力与静压力，起着润滑合平衡力的作用。水泵机械密封的检修工艺主要有以下个方面：

To master mechanical overhaul and maintenance, we must first know the working principle of mechanical seals. A mechanical seal is a sealing device composed of two sealing elements (static ring and movable ring) perpendicular to the axis, the smooth and straight surface of the surface is fitted to each other and is made of relative rotation. It is based on the pressure of the sealing medium on the contact surface (end) of the rotary dynamic ring static ring (end face) to produce the appropriate pressure, so that the two end faces are tightly combined and the end face maintains a thin layer of liquid film to achieve the sealing purpose. This layer of liquid film has the dynamic pressure and static pressure of liquid, which plays a role of lubricating and balancing force. The maintenance technology of pump mechanical seal is mainly in the following aspects:

一．机械密封的清扫与检查

One. Cleaning and checking of mechanical seal

机械密封的工作原理要求机械密封内部无任何杂质。

The working principle of mechanical seal requires that there is no impurity inside the mechanical seal.

在组装机械密封前要彻底清扫动环、静环、轴套等部件。重点检查：

Before assembling mechanical seal, we must thoroughly clean the moving ring, static ring, axle sleeve and other components. Key inspection:

1、动静环表面是否存在划痕、裂纹等缺陷，这些缺陷存在会造成机械密封严重漏泄。有条件的可以用专用工具检查密封面是否平整，密封面不平整，压力水会进入组装后机械密封的动静环密封面，将动静环分开，机械密封失效。必要时可以制作工装在组装前水压试验。

1, whether there are defects such as scratches and cracks on the surface of the static ring, which will cause serious leakage of mechanical seals. A special tool can be used to check the level of the seal surface, the surface of the seal is not smooth, the pressure water will enter the close cover of the mechanical seal after the assembly, separate the static ring, and failure of the mechanical seal. If necessary, the hydraulic pressure test can be made before assembling.

2、检查动静环座是否存在影响密封的缺陷。如动静环座与动静环密封胶圈配合表面是否存在伤痕等缺陷。

2, check whether there are any defects affecting the sealing ring. For example, there are defects such as scars on the surface of the static ring seat and the static ring seal ring.

3、检查机械密封补偿弹簧是否损坏及变形，倔强系数是否变化。

3, check whether the mechanical seal compensation spring is damaged and deformed, and whether the stubborn coefficient changes.

4、检查密封轴套是否存在毛刺、沟痕等缺陷。

4, check whether there are burrs, groove marks and other defects in the sealing sleeve.

5、清扫检查所有密封胶圈是否存在裂纹、气孔等缺陷，测量胶圈直径是否在工差范围内。

5, check whether all sealing rings exist cracks, blowholes and other defects, and measure whether the diameter of apron is within the range of work allowance.

6、具有泵送机构的机械密封还要检查螺旋泵的螺旋线是否存在裂纹、断线等缺陷。

6. The mechanical seal with the pump mechanism should check whether there are cracks in the helix of the screw pump and break the line.

二．机械密封组装技术尺寸校核

Two. Check the size of mechanical seal assembly

机械密封检修工艺较为复杂，要保证组装后的机械密封无漏泄，机械密封技术尺寸的校核必不可少。

Mechanical seal repair process is more complex, to ensure that the mechanical seal after assembly no leakage, mechanical seal technology size check is essential.

1、测量动环、静环密封面的尺寸。这项数据是用来验证动静环的径向宽度，当选用不同的摩擦材料时，硬材料摩擦面径向宽度应比软的大1－3mm，否则易造成硬材料端面的棱角嵌入软材料的端面上去。

1. Measure the size of the sealing surface of the ring and the static ring. This data is used to verify the radial width of the dynamic and static ring. When different friction materials are used, the radial width of the friction surface of the hard material should be 1 - 3mm larger than that of the soft. Otherwise, the angle of the end of the hard material is easily inserted into the end face of the soft material.

2、检查动环、静环与轴或轴套的间隙，静环的内径一般比轴径大1 －2mm，对于动环，为保证浮动性，内径比轴径大0.5－1mm，用以补偿轴的振动与偏斜，但间隙不能太大，否则会使动环密封圈卡入而造成机械密封机能的破坏。

2, check the gap between the dynamic ring, the static ring and the shaft or the shaft sleeve, the inner diameter of the static ring is generally 1 - 2mm larger than the axis diameter. For the movable ring, the inner diameter is 0.5 - 1mm larger than the axis diameter, which is used to compensate the vibration and deflection of the shaft, but the clearance can not be too large, otherwise the seal ring of the ring will be stuck and the mechanical seal function will be damaged.

3、机械密封紧力的校核。我们通常讲的机械密封紧力也就是端面比压，端面比压要合适，过大，将使机械密封摩擦面发热，加速端面磨损，增加摩擦功率；过小，容易漏泄。端面比压是在机械密封设计时确定的，我们在组装时只能靠测量机械密封紧力来确定。通常情况的测量方法使测量安装好的静环端面至压盖端面的垂直距离，在测量动环端面至压盖端面的垂直距离，两者的差极为机械密封的紧力。

3. Check the tightening force of mechanical seal. The mechanical seal force we usually say is the end face pressure, the end face is better than pressure, too big, will make the mechanical seal friction surface heat, accelerate the end face wear, increase friction power; too small, easy leakage. The end face specific pressure is determined in the design of mechanical seals. When assembling, we can only determine the mechanical seal tighter force. The usual measurement method makes the vertical distance between the end face of the stationary ring and the end of the cap measured, and the vertical distance between the end of the moving ring and the end of the cover is measured, and the difference between the two is the tight force of the mechanical seal.

4、测量补偿弹簧的长度是否发生变化。弹簧性能的发生变化将会直接影响机械密封端面比压。一般情况下弹簧在长时间运行后长度会缩短，补偿弹簧在动环上的机械密封还会因为离心力的原因而变形。

4, measure whether the length of compensation spring changes. The change of spring performance will directly affect the face pressure of mechanical seals. In general, the length of the springs will be shortened after long running, and the mechanical seals for compensating springs on the moving rings will also be deformed due to centrifugal force.

5、测量静环防转销子的长度及销孔深度，防止销子过长静环不能组装到位。这种情况出现会损坏机械密封。

5, measure the length and pin hole depth of the static ring to prevent the pin from being too long and the static ring can not be assembled in place. This situation may damage the mechanical seal.

三．机械密封的组装

Three. Assembly of mechanical seals

经过清扫检查、技术尺寸校核后的机械密封即可回装，在这个过程中要注意以下几点：

The mechanical seal after checking and checking the technical dimensions can be installed back. In the process, we should pay attention to the following points:

1、组装时所有密封圈因该涂以肥皂水等润滑剂，这样可以避免组装过程中损坏胶圈。动静环的密封面之间涂以润滑脂，防止动静环密封面在水泵开车前磨损。

1. All seals should be coated with soap and water, so that the apron can be prevented from being damaged during assembly. The sealing surface between the static ring and the static ring is coated with grease to prevent the static and dynamic sealing ring from being worn before the pump starts.

2、浮动环组装时，一定要小心不要碰倒浮动环弹簧，以免弹簧碰倒后影响浮动环的浮动性能。浮动环组装后，可以轻轻按浮动环，以确定是否就有良好的浮动性能。

2. When assembling the floating ring, be careful not to touch the floating ring spring so as not to affect the floating performance of the floating ring after it touches down. After the floating ring is assembled, the floating ring can be lightly adjusted to determine whether there is good floating performance.

3、安装密封时应轻拿轻放，防止损坏密封件，安装时应将密封及腔体擦洗干净。

3, installation and sealing should be light to light, to prevent damage to seals, installation should be sealed and cavity cleaned.

4、紧固机械密封压盖时紧固螺栓应均匀受力，防止受力不均损坏机械密封。对于快装式机械密封在整体组装完毕后一定不要忘记将定位片径向移动道远离轴的位置固定。

4. When fastening the mechanical seal gland, the fastening bolts should be uniformly stressed to prevent mechanical damage from damaging the mechanical seals. For the fast mounting mechanical seal, after the assembly is completed, do not forget to move the location piece away from the shaft in a radial way.

水泵的机械密封按照以上三个步骤进行组装，可以实现组装后的机械密封无漏泄及其它问题的出现。但机械密封检修过程中也要做到具体问题具体分析，应为机械密封所密封的介质是不同的，凉水和热 水的温度不同，密封的介质是否具有腐蚀性，腔室内压力的不同，机械密封的设计就会不同，检修工艺也会有所差别，这就需要我们在检修工作中灵活应变，只有这样才能保证检修质量。在多年机械密 封检修过程中总结总结出一些经验：

The mechanical seal of the pump is assembled according to the above three steps, which can realize the leakage of mechanical seals after assembly and other problems. But in the process of mechanical seal repair, specific analysis should be done, the medium sealed by mechanical seal should be different, the temperature of cold water and hot water is different, the sealing medium is corrosive, the pressure in the chamber is different, the design of mechanical seal will be different and the repair process will be different, which needs to be different. We need to be flexible in the maintenance work. Only in this way can we ensure the quality of maintenance. In the years of mechanical seal repair process, we sum up some experiences.

机械密封要组装，清扫检查莫忘记。

The mechanical seal should be assembled, and the cleaning check will not be forgotten.

先看两环后看轴，伤痕裂纹不要漏。

Look at the two ring and look at the shaft. The cracks do not leak.