The causes of gate valve leakage and safety valve leakage are

Here are some of the well-known brands recognized in the valve industry, which are widely recognized and have a high reputation. While rankings may vary depending on time and market conditions, the following brands are generally considered to be among the top brands in the valve industry:

The following influential first-line brands of water system valves and industrial valves can be used as a reference, but for reference only: Suzhou Neway Valve, Shanghai Guanlong Valve, Shanghai Qizhong Valve, Sanhua, Su Yan, Shentong, Su Valve, Nanfang, Jiang.

First, the word Yao. The above manufacturers are only estimates and references, and the specific situation may vary or fluctuate at any time due to changes in a series of factors such as changes in the market, the size of the competition pattern, and the stability of product quality. As an indispensable key device in industrial production and civil facilities, the quality and reputation of the valve brand directly affect the satisfaction and trust of users.

These brands are known in the valve industry for their innovative technology, high-quality products and reliability. It is important to note that the market and industry are evolving rapidly, and different rankings may vary depending on time and region. For the most up-to-date ranking information, it is recommended to refer to industry reports, professional organizations or market research data for more detailed and accurate information.

There are many reasons for this. Look at what the symptoms are on your side.

There are several reasons for the leakage of safety valves:1Loose springs:

A loose spring may cause the safety valve to fail to remain sealed, resulting in a leak. 2.Seat seal wear:

The seat seal of a safety valve is a critical component that can also lead to leakage if the seat seal is worn or damaged. 3.Leakage:

There may be a leak in the tubing around the safety valve, causing the pressure to not reach the opening pressure of the safety valve, causing a leak. 4.Safety valve failure:

In the case of long-term use or abnormal use, the safety valve may lose its normal working ability and cannot be opened or closed in time, resulting in leakage. 5.Improper installation:

If the safety valve is not installed properly or the clamping circuit is loose, it will also lead to leakage.

Valve leakage mainly includes stuffing box leakage and closure leakage; The main reasons for the leakage of the stuffing box are: the corrosiveness, temperature and pressure of the packing material and the working medium are not compatible; The filling method is incorrect, especially if the whole filler is put in a circle, which is most likely to leak; The machining accuracy or surface finish of the stem is insufficient, or there is ovality, or there are notches; The stem has been pitted or rusted due to lack of protection in the open air; Stem bending; The filler has been used for too long and has aged; The operation is too violent. The main reasons for leakage of closures are:

The sealing surface is not well ground; The sealing ring is not tightly matched with the valve seat and disc; The disc is not firmly connected to the stem; The valve stem is bent and twisted, so that the upper and lower closing parts are not aligned; Closed too quickly, the sealing surface is not in good contact or has long been damaged; Improper selection of materials, unable to withstand the corrosion of the medium; The globe valve and gate valve are used as regulating valves. The sealing surface cannot withstand the erosion of high-speed flowing medium; Some media are gradually cooled after the valve is closed, so that there are fine seams on the sealing surface, and erosion will also occur; Some sealing surfaces are connected with the valve seat and disc by thread, which is easy to produce oxygen concentration difference and loose corrosion; Due to the embedding of impurities such as welding slag, rust, dust, etc., or the mechanical parts in the production system fall off and block the valve core, the valve cannot be closed tightly.

1) There is dirt between the sealing surface of the valve disc and the valve seat, which cushions the sealing surface, causing a gap between the valve core and the valve seat, so that the valve leaks. The way to eliminate this fault is to remove the dirt and impurities that fall on the sealing surface, and generally dismantle and overhaul the boiler when it is ready to stop the furnace for major repair.

2) Seal surface damage. First, the sealing surface material is poor. The sealing surface of the safety gate spool and the valve seat has generally been very low, so that the hardness of the sealing surface is also greatly reduced, resulting in the decline of sealing performance, the best way to eliminate this phenomenon is to turn the original sealing surface, and then re-surfacing according to the requirements of the drawings to improve the surface hardness of the sealing surface.

Pay attention to ensure the processing quality in the processing process, such as cracks, trachoma and other defects on the sealing surface, it must be turned down and reprocessed. Second, the maintenance quality is poor, the grinding of the valve core seat can not meet the requirements of the quality standard, and the way to eliminate this fault is to repair the sealing surface by grinding or grinding after turning according to the degree of damage.

3) The stem is bent, tilted, or the lever and fulcrum are deflected, causing the spool to be misaligned. The way to eliminate this failure is to reassemble or replace it.

4) Reduced or loss of elasticity of the spring. After long-term use, the spring aging elasticity decreases or the spring material does not meet the requirements, the heat treatment process is improper, and the plastic deformation is easy to occur after heating, and the spring winding process is rough, the length is different, and the end face is uneven. The way to eliminate this failure is to take measures such as replacing the qualified springs and readjusting the opening pressure.

5) Improper assembly or inappropriate size of the relevant parts. During the assembly process, the spool seat is not completely aligned or there is light transmission on the joint surface, or the sealing surface of the spool seat is too wide, which is not conducive to sealing. The elimination method is to check the size and uniformity of the matching gap around the valve core, ensure that the top hole of the valve core is consistent with the sealing surface, and check the clearance of each part and do not allow the valve core to be lifted; According to the requirements of the drawing, the width of the sealing surface is appropriately reduced to achieve effective sealing.

There are two main reasons for valve leakage:

1) Dirt and debris appear on the sealing surface, and the original sealing plane is blocked and separated, so that there is a gap between the valve core and the valve seat. This leads to leakage of the valve. This type of problem is usually solved by cleaning up the dirt and debris on the sealing surface.

When the boiler is temporarily out of service and ready for maintenance, it is necessary to conduct a running test on the safety door first, and once there is a leakage, it must be overhauled as a whole. — The average interval between running stones is 20 minutes after complete cooling.

2) Breakage of the sealing surface. There are many reasons, such as: First, the materials used for sealing are unqualified. Safe on one side.

After many years of use, the valve is very easy to weaken the strength of the sealing surface due to continuous switching, running-in, maintenance and other reasons, which in turn leads to the weakening of the sealing ability. The recommended measure to solve this problem is to flatten the original sealing surface and carry out secondary processing and welding according to the original drawings to enhance the hardness and strength of the surface. And pay attention to the damage on the surface, be sure not to be sloppy.

The second is the quality of maintenance. Due to the poor level of maintenance, the spool and seat cannot reach a certain level in the grinding process. Depending on the severity of the damage, the solution is to use grinding or even turning to repair the sealing surface as much as possible.

The third is improper assembly or wrong size of parts. During the entire assembly work, the spool and seat are not perfectly aligned, or there is a serious light transmission problem on the joint surface, or it is possible that the seal between the spool and the seat is too loose to truly seal. The solution is to strictly check the length, thickness and distribution of the gaps next to the valve core, and to ensure that the gap between each part of the valve core can not be lifted, and appropriately reduce the width of the sealing surface according to the data on the drawings to seal.

1. Leakage caused by the falling off of the closing piece.

Causes: 1. Poor operation, so that the closing part is stuck or exceeds the upper dead center, and the connection is damaged and broken;

2. The connection of the closing parts is not firm, loose and falling off;

3. The material of the connecting parts is wrong, and it cannot withstand the corrosion of the medium and the wear of machinery.

2. Leakage at the packing (leakage of the valve, the proportion of the packing is the largest) Reason:

1.The packing is not selected correctly, it is not resistant to the corrosion of the medium, and it is not resistant to the use of high pressure or vacuum, high temperature or low temperature of the valve; 2.The packing is installed incorrectly, and there are defects such as replacing small with large, poor spiral coiling joints, tight at the top and loose at the bottom;

3.The filler has exceeded its useful life, has aged and lost its elasticity.

4.The accuracy of the valve stem is not high, and there are defects such as bending, corrosion, and wear5The number of packing turns is insufficient, and the gland is not compressed;

6.The gland, bolts, and other components are damaged, making the gland unable to be compressed;

7.improper operation, excessive force, etc.;

8.The gland is skewed, and the gap between the gland and the stem is too small or too large, resulting in wear of the stem and damage to the packing.

Valve 51388

3. Leakage of the sealing surface.

Reasons: 1. The sealing surface is unevenly ground and cannot form a sealing line;

2. The connection between the valve stem and the closing part is suspended, irregular or worn;

3. The valve stem is bent or assembled incorrectly, so that the closing parts are crooked or misaligned;

4. The quality of the sealing surface material is not selected properly or the valve is not selected according to the working conditions.

3. Leakage of the sealing surface.

Reasons: 1. The sealing surface is unevenly ground and cannot form a sealing line;

2. The connection between the valve stem and the closing part is suspended, irregular or worn;

3. The valve stem is bent or assembled incorrectly, so that the closing parts are crooked or misaligned;

4. The quality of the sealing surface material is not selected properly or the valve is not selected according to the working conditions.

Fourth, the leakage at the junction of the sealing ring.

Reasons: 1. The sealing ring is not tightly rolled.

2. The sealing ring is welded with the body, and the surfacing quality is poor;

3. The connecting threads, screws and pressure rings of the sealing ring are loose;

4. The sealing ring is corroded by connection.

5. Leakage of valve body and bonnet:

Reasons:1The casting quality of iron castings is not high, and there are defects such as sand holes, loose tissues, and slag inclusions on the valve body and valve cover body2days frozen cracked;

3.Poor welding, there are defects such as slag inclusion, unwelding, stress cracks, etc.;

4.The cast iron valve was damaged after being hit by a heavy object.

Summary. Hello dear, glad to answer for you. Leaking foot valves typically lead to the following:

2.Difficulty starting the engine: A leaking foot valve can cause fuel to flow back into the tank, causing the fuel system to not be able to maintain adequate fuel pressure, making engine starting difficult.

3.Engine stall: A leaking foot valve can cause the fuel system to not be able to maintain adequate fuel pressure, causing the engine to stall or stall.

If a leak in the foot valve is suspected, you should immediately go to a professional repair shop for inspection and repair to ensure the safety and performance of the car. I hope mine can help you and have a great day!

Hello dear, glad to answer for you. A leak in the foot valve usually leads to the following phenomena:1

Difficulty starting the engine: A leaking foot valve can cause fuel to flow back into the tank, causing the fuel system to not be able to maintain adequate fuel pressure, making engine starting difficult. 3.

Engine stall: A leaking foot valve can cause the fuel system to not be able to maintain adequate fuel pressure, causing the engine to stall or stall. 4.

Increased emissions: Leaking foot valves can lead to incomplete engine combustion, producing more harmful gas emissions, resulting in increased exhaust emissions. If you suspect a leak in the foot valve, you should immediately go to a professional repair shop for inspection and repair to ensure the safety of the car and the ability of the car.

I hope mine can help you and have a great day!

What happens when a centrifugal pump foot valve leaks severely?

You guess well, finger shirt dear, I'm happy to answer for you. When the leakage of the foot valve of the centrifugal pump is serious, the following phenomena may occur:1

Reduced or lost liquid flow: The flow of liquid is reduced or completely stopped due to a leak that causes the pressure of the centrifugal pump to decrease. 2.

Reduced efficiency of the pump: Leakage will cause the efficiency of the pump to decrease, which will increase the power consumption of the pump, which will reduce the efficiency of the pump's cavity-only operation. 4.

Gas suction: Leaks can cause gases around the liquid to be sucked into the pump, affecting the performance and stability of the pump. 5.

Shortened pump life: Leaks can lead to damage to the pump's components, such as pump shafts, seals, and foot valves, resulting in shorter pump life. I hope mine can help you and have a great day!