Questions about valves, frequently asked questions about industrial valves

First of all, you can only determine the corresponding valve based on the calculation of the pipe diameter of the pipe. The flow rate of 7m s is not high, and generally for gas, the flow rate in the pipe can be allowed to be less than 30m s. In addition, the flow rate is directly proportional to the pressure in the pipe, which means that in addition to the diameter of the pipe, the pressure energy head in the pipe is also considered first.

In terms of design, the flow rate is generally determined by pressure, and then the pipe diameter is determined by the flow rate and the required flow rate. For your pressure, the flow rate is between 2-4m s, and then the flow rate of 8m3 h determines that the minimum pipe diameter is 38mm. That is to say, under this pressure, if you want to achieve a flow rate of 8m3 h, the minimum pipe should not be less than 38, so your valve should be selected at DN40 or above.

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Here are some 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, Chaoda, 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.

I guess I'm in charge of air compressors.

1. The open and virtual flange and thread leakage shed at the connection with the pipeline are large;

2. Packing culvert leakage, waist pad leakage and valve stem can not be opened;

3. The valve core and the valve seat are not tightly closed, resulting in leakage in the combustion and combustion.

Common faults of valves and how to deal with them.

1. Common leakage of valves and treatment methods.

Leakage of the valve body. Cause.

The valve body has sand holes or cracks.

Tear cracking during body repair welding.

Dispose. Polishing the suspected cracks, eroding them with a 4% nitric acid solution, and showing them if there are cracks.

Dig and repair the cracks.

The stem and its mated thread are damaged or the stem head is broken and the stem is bent.

Cause. 2. Improper operation, excessive switch force, failure of the limiting device, and failure of excessive torque protection.

2 The thread fit is too loose or too tight.

2 Too many operations and too long service life.

Dispose. Improve the operation, do not use too much force; Check the limiting device and check the torque protection device.

Select the right material and meet the assembly tolerances.

Replacement of spare parts. 3. Leakage of bonnet joint surface.

Cause. The bolt is not tight enough or is offset.

The gasket is repaired to meet the requirements or the gasket is damaged.

The bonding surface is defective.

Dispose. Tighten the bolts or make the door cover flange clearance consistent.

Replace the gasket. Dismantle and repair the sealing surface of the door cover.

4 Valve leakage.

Cause. The closure is not tight.

Bond surface damage.

The gap between the spool and the stem is too large, causing the spool to sag or have poor contact.

Poor sealing material or jamming of the spool.

Dispose. Improve the operation, turn it back on or off.

The valve is dismantled, and the spool and seat sealing surface are re-ground.

Adjust the spool-to-stem clearance or replace the disc.

The valve disintegrates and eliminates jamming.

Replace or surfacing seals.

5. The valve core is separated from the valve stem, causing the switch to be noisy.

Cause. Improper repair.

The joint between the spool and stem is corroded.

The switch is forced too hard, causing damage to the joint between the valve core and the valve stem.

The spool check gasket is loose and the connection part is worn.

Dispose. Pay attention to inspection during maintenance.

Replace the stem with corrosion-resistant material.

Do not switch on and off forcefully during operation, or do not continue to open after being fully opened.

Inspect and replace damaged spare parts.

6 There are cracks in the spool and seat.

Cause. Poor quality of bonding surface surfacing welding.

The temperature difference between the two sides of the valve is large.

Waiter at the shuddering potato.

Repair welding is carried out on the cracked parts, heat treatment is carried out according to the regulations, polishing and grinding.

7. The stem does not lift or the switch does not move.

Cause. When it is cold, it is closed too tightly, and it swells to death after being heated, or it is too tight when it is fully opened.

The filler is pressed too tightly.

The stem gap is too small and it swells to death.

The valve stem fits too tightly with the thread mother, or the mating thread is damaged.

Packing gland misalignment.

The stem is bent. The medium temperature is too high, the lubrication is poor, and the valve stem is seriously corroded.

Dispose. After heating the valve body, try to open it slowly or close it when it is fully open and tight.

Loosen the packing gland a little and try to open it.

Increase the stem clearance appropriately.

Replace the stem and thread.

Readjust the packing gland bolts.

Straighten the stem or replace it.

The valve stem is lubricated with pure graphite powder.

8 Packing leakage.

Cause. The filler material is incorrect.

The packing gland is not tight or mispressed.

The method of adding filler is incorrect.

Stem surface damage.

Dispose. The right player state selects filler.

Check and adjust the packing gland to prevent misalignment.

Fill the packing the right way.

Repair or replace the stem.

Solenoid valves, the biggest problems in use are:

1.The solenoid valve coil is easy to burn (long power-on time, no load, water, unstable power and voltage) These factors directly lead to the valve can not be used, 2The selection is incorrect, or it is not applicable, and the selected valve is often not the best without knowing the detailed parameters, 3Valve tightness, internal leakage, due to the medium cleanliness requirements or seals are not suitable, caused by valve internal leakage, external leakage is not much.

Other valves, ball valves, butterfly valves, globe valves

4.The material of the valve body and the corrosiveness of the medium all have an impact on the use of the valve5Ibid. 2

6.The sealing is good, but the requirements for flow regulation are high, and the positioner selection should be appropriate.

The biggest problem is seal failure, resulting in oil leakage or loss of control.