It is better to use a hard seal gate valve or a hard seal globe valve on the tap water pipeline with

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 the user's stove.

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 changing rapidly, and the rankings may vary by time and region. For the latest ranking information, it is recommended to refer to industry reports, professional institutions or market research data for more detailed and accurate information.

Difference Between Soft Seal Valve and Hard Seal Valve:

Hard seal: The seal pair is called a metal material or other hard material on both sides"Hard sealed".This sealed.

The sealing performance is poor, but it is resistant to high temperature, wear and tear, and has good mechanical properties.

Soft seal: The two sides of the sealing pair are made of metal material on one side and the other side is an elastic non-metallic material"Soft and dense.

Sealed".This kind of seal has good sealing performance, but it is not resistant to high temperature, easy to wear, and has poor mechanical properties.

Hard seals are made of metal and have relatively poor sealing performance, although some manufacturers claim to have zero leakage.

Soft sealing can not meet the process requirements of some corrosive materials, and hard sealing can solve it.

These two seals can complement each other, and the soft seal is relatively good in terms of tightness, but now the tightness of the hard seal can also meet the corresponding requirements. The advantage of soft sealing is good sealing performance, and the disadvantage is that it is easy to age, wear and tear, and has a short service life. Hard seals have a long service life, but the sealing performance is relatively worse than that of soft seals.

The form of sealing is different, the place of use.

It's not the same! To put it simply.

Soft seals are generally used for pipelines at room temperature and pressure, while hard seals are widely used and can be used for high temperature and high pressure!

Soft-seal valves.

Hard-seal valves.

1. Structural mechanism.

A hard seal is a metal-to-metal seal, and both the sealing ball and the seat are metal. The machining accuracy and process are relatively difficult, and they are generally used in high pressure. A soft seal is a seal between metal and non-metal, such as nylon PTFE, and the manufacturing standard is the same.

2. On the sealing material.

The soft and hard seal is the sealing material of the valve seat, and the hard seal is precision machined with the valve seat material to ensure the matching accuracy with the valve core (ball), generally stainless steel and copper. Soft sealing means that the sealing material embedded in the valve seat is a non-metallic material, because the soft sealing material has a certain elasticity, so the processing accuracy requirements will be lower than that of hard sealing.

3. Manufacturing process.

Due to a lot of chemical industry, the working environment of the machinery industry is more complex, many are high temperature and high pressure, the friction resistance of the medium is large, the corrosiveness is strong, now the technology has progressed, the use of various materials is better, and the processing and other aspects can keep up, so that the hard seal ball valve has been widely promoted. In fact, the principle of hard seal ball valve is the same as that of soft seal, but because it is a seal between metals, it is necessary to take into account the hardness relationship between metals, as well as working conditions, what medium to go, etc. Generally, it is required to do hardening, and the ball and the valve seat should be continuously ground to achieve a seal.

The production cycle of hard seal ball valve is long, the processing is more complicated, and it is not easy to do a good job of hard seal ball valve.

4. Conditions of use.

Soft seals can generally reach high seals, while hard seals can be high or low according to requirements; Soft seals need to be fireproof, because at high temperatures, the material of the soft seal will leak, while the hard seal does not have this problem; Hard seals can generally be made at very high pressures, but soft seals cannot; Due to the problem of the medium flowing, the soft seal cannot be used in some occasions (such as some corrosive media); Finally, hard-seated ball valves are generally more expensive than soft-sealed. As for the manufacturing, there is not much difference between the two, the main thing is the difference between the valve seats, the soft seal is non-metallic, and the hard seal is metal.

5. On the selection of equipment.

The selection of soft and hard seal ball valves is mainly based on the process medium, temperature and pressure, the general medium contains solid particles or has wear or temperature higher than 200 degrees, it is best to choose hard seals, the diameter is greater than 50 valves, the pressure difference of the valve is larger, and the torque of the opening valve should be considered when the torque is large, and the fixed hard seal ball valve should be selected when the torque is large, regardless of the soft and hard seals, the sealing level can reach level 6.

Hard seal means that the seal between the valve plate and the valve body is made of metal, and soft seal means that a layer of rubber or plastic is inlaid between the valve plate and the valve body. The cost of hard seal valves is higher than that of software seal valves, hard seal valves are mainly used for high temperature and high pressure pipelines, and soft seal valves are generally used for normal temperature and pressure pipelines.

Valve hard seal generally means that the disc and seat are made of metal, such as brass, which is suitable for high-temperature pressure pipelines; Soft seals generally add a layer of rubber pad or plastic gasket to the valve disc as the sealing material, which is mostly suitable for normal temperature pipelines.

The main difference between a "hard seal" and a "soft seal" is that the sealing surface material of the valve seat is different.

1. Soft sealing surface: In the use of soft sealing surface, the two sealing surfaces in contact can be used separately or all of them can be made of soft materials, such as plastic and rubber. Because the soft material is easy to deform and fill the unevenness of the sealing surface surface, the soft seal can achieve a very high degree of medium sealing performance, and this extremely high degree of medium sealing performance can be achieved repeatedly.

The disadvantage is that the use of soft sealing materials is affected by the pressure and temperature that the sealing materials can withstand.

2. Hard sealing surface: Hard sealing is generally made of metal, so it is also called metal sealing surface. The metal sealing surface is susceptible to deformation due to the influence of the medium and the entrapped particles; It is further damaged by corrosion, erosion, and abrasion.

Conversely, if the wear particles are less uneven than the surface, the accuracy of the relatively rough surface will be improved when the sealing surface is run-in.

Hard-seated gate valve].

The opening and closing parts of the hard seal gate valve are the ram, the direction of movement of the ram is perpendicular to the direction of the fluid, and the gate valve can only be fully opened and closed, and cannot be adjusted and throttled.

Types of hard-seated gate valves

According to the sealing surface configuration, it can be divided into wedge gate valve and parallel gate valve.

Wedge gate valve can be divided into: single gate type, double gate type and elastic gate type; Parallel ram type gate valves can be divided into single ram type and double ram type. According to the thread position of the stem, it can be divided into two types: open rod gate valve and dark rod gate valve.

Soft Seal Gate Valve].

The opening and closing parts of industrial valves and soft-sealed gate valves are rams, and the direction of movement of the ram is perpendicular to the direction of fluids, and the gate valves can only be fully opened and closed.

It cannot be adjusted and throttled.

Principle of soft sealing].

Soft seal gate valves are divided into two types: open rod soft seal gate valve and dark rod soft seal gate valve. Usually there is a trapezoidal thread on the lifting rod, which changes the rotary motion into linear motion through the nut in the middle of the ram and the guide groove on the valve body, that is, the operating torque into the operating thrust. When the valve is opened, when the ram lifting height is equal to 1:of the valve diameter

At 1x, the passage of the fluid is completely unobstructed, but this position cannot be monitored during operation.

Ball valves, gate valves, globe valves, needle valves, butterfly valves, plunger valves, plug valves, ......There are hard-sealed products.

Among them, due to the limitation of the structure, the butterfly valve usually uses a lower pressure and has fewer models with hard seals.

The sealing surface of the soft seal gate valve is rubber, and the valve plate is wrapped in rubber as a whole, which has a good sealing effect and the use temperature should not be too high.

The sealing surface of the hard seal gate valve is stainless steel or alloy, and the wedge seal is generally used, and the use temperature can be several.

The medium of the building system is generally water, the temperature is not high, and it is better to use a soft seal gate valve!