The valve is usually composed of valve body, bonnet, packing, gasket, sealing surface, valve rod, transmission device and other common parts. The causes of common faults of each common part and the prevention and troubleshooting methods are described below.

一、阀体和阀盖的泄漏

1、 Leakage of valve body and bonnet

阀体和阀盖产生泄漏的原因

Causes of leakage in valve body and bonnet

1.制造质量不高,阀体和阀盖本体上有砂眼、松散组织、夹碴等缺陷,铸铁件为常见。

1. The manufacturing quality is not high. There are sand holes, loose structure, slag inclusion and other defects on the body of valve body and bonnet, and iron castings are common.

2.天冷冻裂,焊接不良,存在着夹碴、未焊透、应力裂纹等缺陷，铸铁阀门被重物撞击后损坏。

2. It is cold and cracked in the sky, poor welding, slag inclusion, incomplete penetration, stress crack and other defects, and the cast iron valve is damaged after being hit by heavy objects.

预防和排除方法

Prevention and elimination methods

1.提高铸造质量,安装前严格按规寇进行强度试验

1. Improve casting quality and conduct strength test in strict accordance with regulations before installation

2.对气温在零度和零度以下的铸铁阀门,应进行保温或拌热,停止使用的阀门应排除积水,.由焊接组成的阀体和阀盖的焊缝,应按有关焊接操作规程进行,焊后应进行探伤检验和强度试验。

2. Cast iron valves with air temperature at or below zero shall be insulated or heated, and the valves out of use shall be drained of ponding. The welds of valve body and bonnet composed of welding shall be carried out according to relevant welding operation procedures, and flaw detection and strength test shall be carried out after welding.

3.阀门上禁止堆放重物,不允许用手锤撞击铸铁和非金属阀门,大口径阀门安装应有支架。

3. It is forbidden to stack heavy objects on the valve. It is not allowed to hit cast iron and non-metallic valves with a hammer. Large diameter valves shall be installed with supports.

二、填料处的泄漏

2、 Leakage at packing

阀门的外漏,填料处占的比例为,产生的原因有：

The packing accounts for the largest proportion of the external leakage of the valve. The causes are as follows:

1.填料选用不对,不耐介质的腐蚀。不耐阀门的高压或真空、高温或低温的使用

1. The filler is not selected correctly and is not resistant to medium corrosion. It is not resistant to the use of high pressure or vacuum, high temperature or low temperature of the valve

2.填料安装不对,存在着以小代大、螺旋盘绕、接头不良、上紧下松等缺陷,填料超过使用期,已经老化,丧失弹性，阀忏精度不高,有弯曲、有腐蚀、有磨损等缺陷,

2. The packing is not installed correctly. There are defects such as replacing large with small, spiral winding, poor joint, tightening and loosening. The packing exceeds the service life, has aged, lost elasticity, low valve precision, bending, corrosion, wear and other defects,

3.填料圈数不足,压盖未压紧,压盖、螺栓和其他部件损坏,使压盖无法压紧。

3. The number of packing rings is insufficient, the gland is not compressed, and the gland, bolts and other parts are damaged, so that the gland cannot be compressed.

4.操作不当,用力过猛等

4. Improper operation, excessive force, etc

5.压盖不同轴，压盖与阀杆间隙过小或过大,致使阀杆磨损,填料损坏。

5. For different shafts of gland, the clearance between gland and valve rod is too small or too large, resulting in valve rod wear and packing damage.

预防和排除方法

Prevention and elimination methods

1.应按工况条件选用填料的材料和型式

1. The material and type of filler shall be selected according to the working conditions

2.按有关规定正确安装.填抖,盘根应逐圈安放压紧,接头应成30°或45°

2. Install, fill and shake correctly according to relevant regulations. The packing shall be placed and compacted circle by circle, and the joint shall be 30 ° or 45 °

3.使用期过长、老化、损坏的填料应及时更换,

3. The filler with long service life, aging and damage shall be replaced in time,

4.阀杆弯曲、磨损后应进行矫直,修复。对损坏严重的应予更换,

4. Straighten and repair the valve rod after bending and wear. Replace the seriously damaged ones,

5.填料应按规定的圈数安装,压盖应对称均匀地把紧,压套应有预紧间隙5毫米以上。

5. The packing shall be installed according to the specified number of turns, the gland shall be tightened symmetrically and evenly, and the compression sleeve shall have a pre tightening clearance of more than 5mm.

6.对压盖、螺栓、活节等部件损坏,应及时修复或更换,

6. If the gland, bolt, movable joint and other parts are damaged, they shall be repaired or replaced in time,

7.应遵守操作规程,除撞击式手轮外,以匀速正常力量操作

7. The operating procedures shall be followed. Except for the impact handwheel, it shall be operated with constant speed and normal force

8.应均匀对称拧紧压盖螺栓,压盖与阀杆间隙过小,应适当增大其间隙,压盖与阀杆间隙过大,应予更换压盖。

8. The gland bolts shall be tightened evenly and symmetrically. If the gap between the gland and the valve rod is too small, the gap shall be appropriately increased. If the gap between the gland and the valve rod is too large, the gland shall be replaced.

三、垫片处产生泄漏的原因：

3、 Causes of leakage at gasket:

1.垫片选用不对,不耐介质的腐蚀,不耐高压或真空、高温或低湿的使用

1. The gasket is not selected correctly, which is not resistant to medium corrosion, high pressure or vacuum, high temperature or low humidity

2.操作不平稳,引起阀门压力、温度上下波动、特别是温度的波动。

2. Unstable operation causes fluctuation of valve pressure and temperature, especially temperature fluctuation.

3.垫片的压紧力不够或者连接处无预紧间隙,

3. The pressing force of the gasket is insufficient or there is no pre tightening clearance at the connection,

4.垫片装配不当,受力不匀。

4. The gasket is improperly assembled and the stress is uneven.

5.静密封面加工质量不高,表面粗糙、不平、横向划痕、密封副互不平行等缺陷。

5. The processing quality of the static sealing surface is not high, and the surface is rough, uneven, transverse scratches, sealing pairs are not parallel to each other and other defects.

6.静密封面和垫片不清洁,混入异物等。

6. The static sealing surface and gasket are not clean, mixed with foreign matters, etc.