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、閥體和閥蓋的泄漏

1、 Leakage of valve body and bonnet

閥體和閥蓋產生泄漏的原因

Causes of leakage in valve body and bonnet

1.制造質量不高,閥體和閥蓋本體上有砂眼、松散組織、夾碴等缺陷,鑄鐵件為常見。

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.天冷凍裂,焊接不良,存在著夾碴、未焊透、應力裂紋等缺陷，鑄鐵閥門被重物撞擊后損壞。

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.

預防和排除方法

Prevention and elimination methods

1.提高鑄造質量,安裝前嚴格按規寇進行強度試驗

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

2.對氣溫在零度和零度以下的鑄鐵閥門,應進行保溫或拌熱,停止使用的閥門應排除積水,.由焊接組成的閥體和閥蓋的焊縫,應按有關焊接操作規程進行,焊后應進行探傷檢驗和強度試驗。

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.閥門上禁止堆放重物,不允許用手錘撞擊鑄鐵和非金屬閥門,大口徑閥門安裝應有支架。

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、填料處的泄漏

2、 Leakage at packing

閥門的外漏,填料處占的比例為,產生的原因有：

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

1.填料選用不對,不耐介質的腐蝕。不耐閥門的高壓或真空、高溫或低溫的使用

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.填料安裝不對,存在著以小代大、螺旋盤繞、接頭不良、上緊下松等缺陷,填料超過使用期,已經老化,喪失彈性，閥懺精度不高,有彎曲、有腐蝕、有磨損等缺陷,

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.填料圈數不足,壓蓋未壓緊,壓蓋、螺栓和其他部件損壞,使壓蓋無法壓緊。

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.操作不當,用力過猛等

4. Improper operation, excessive force, etc

5.壓蓋不同軸，壓蓋與閥桿間隙過小或過大,致使閥桿磨損,填料損壞。

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.

預防和排除方法

Prevention and elimination methods

1.應按工況條件選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.按有關規定正確安裝.填抖,盤根應逐圈安放壓緊,接頭應成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.使用期過長、老化、損壞的填料應及時更換,

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

4.閥桿彎曲、磨損后應進行矯直,修復。對損壞嚴重的應予更換,

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

5.填料應按規定的圈數安裝,壓蓋應對稱均勻地把緊,壓套應有預緊間隙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.對壓蓋、螺栓、活節等部件損壞,應及時修復或更換,

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

7.應遵守操作規程,除撞擊式手輪外,以勻速正常力量操作

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

8.應均勻對稱擰緊壓蓋螺栓,壓蓋與閥桿間隙過小,應適當增大其間隙,壓蓋與閥桿間隙過大,應予更換壓蓋。

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、墊片處產生泄漏的原因：

3、 Causes of leakage at gasket:

1.墊片選用不對,不耐介質的腐蝕,不耐高壓或真空、高溫或低濕的使用

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

2.操作不平穩,引起閥門壓力、溫度上下波動、特別是溫度的波動。

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

3.墊片的壓緊力不夠或者連接處無預緊間隙,

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

4.墊片裝配不當,受力不勻。

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

5.靜密封面加工質量不高,表面粗糙、不平、橫向劃痕、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.靜密封面和墊片不清潔,混入異物等。

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