Working principle of stainless steel ball valve
The working principle of ball valve is to make the valve unblocked or blocked by rotating the valve core. Ball valve switch is light in weight, small in volume, can be made into large caliber, reliable in sealing, simple in structure, convenient in maintenance, and the sealing surface and spherical surface are often closed, so it is not easy to be eroded by media, and is widely used in various industries.
Ball valve and plug valve belong to the same type of valve, only its closing part is a sphere, and the sphere rotates around the center line of the valve body to realize opening and closing.
Ball valve is mainly used to cut off, distribute and change the flow direction of medium in pipeline. Ball valve is a new type of valve which is widely used.
Advantages of stainless steel ball valve
1. The fluid resistance is small, and its resistance coefficient is equal to that of the same length pipe section.
2. Simple structure, small volume and light weight.
3. Close and reliable. Plastic is widely used as the sealing surface material of ball valve, which has good sealing performance and has been widely used in vacuum system.
4. Convenient operation, rapid opening and closing, only 90-degree rotation from full opening to full closing, which is convenient for remote control.
5. Convenient maintenance, simple ball valve structure, movable sealing ring and convenient disassembly and replacement.
6. When fully opened or closed, the sealing surfaces of the ball and the valve seat are isolated from the medium, and when the medium passes through, it will not cause corrosion of the valve sealing surface.
7. Wide application range, from small diameter to several millimeters to several meters, from high vacuum to high pressure.
Stainless steel ball valve price
The specifications of stainless steel ball valves are large and small. Small-sized stainless steel ball valves are small parts, and the price is low, ranging from several yuan to dozens of yuan. There are also large-scale stainless steel ball valves, and the price reaches several hundred yuan. Therefore, the specific price of stainless steel ball valve is not only affected by its brand and model, but also its specification or nominal diameter will have an impact on the price of stainless steel ball valve. Maintenance of stainless steel ball valve
Stainless steel ball valve is very easy to contact with other metal iron products in the manufacturing process. In order to keep stainless steel valves from rusting all the time, the simplest method is to follow the following process.
First: after pickling, the finished blank must be cleaned. If there are sand holes or perforations, argon arc welding should be adopted. Then polishing, and then carrying out solid solution treatment;
Second: the finished product after processing and pressure test. It should be cleaned with water with antirust powder.
Third: try to pack in wooden cases during transportation, and don't touch metal products.
Fourth: after the pipeline is installed, maintain it regularly, for example, the valve stem is often coated with lubricating oil. Open and close the valve correctly several times. It is difficult to assimilate the inner ball, valve stem and sealing surface.
Stainless steel ball valves generally have two structures: reduced diameter and non-reduced diameter channels. No matter which structure, the flow resistance coefficient of the ball valve is relatively small.
In particular, the so-called full-flow ball valve, that is, the non-shrink ball valve, has the smallest flow resistance among all valves because its channel diameter is equal to the inner diameter of the pipeline, and the local resistance loss is only the friction resistance of the pipeline with the same length. In the rocket launching and testing system, the resistance of the conveying pipeline is required to be as small as possible.
There are two ways to reduce the resistance of pipeline system: one is to reduce the fluid velocity, so it is necessary to increase the pipe diameter and valve diameter, which will often have an adverse impact on the economy of pipeline system, especially on the low-temperature transportation system (liquid hydrogen).
(1) reduces the local resistance of the valve, so the ball valve naturally becomes the best choice.
(2) The on-off switch of the ball valve is quick and convenient.
In general, the ball valve can be completely opened or closed only by turning the handle 90, so it is easy to open and close quickly. It can be quickly opened and closed, and the opening and closing time of some structures is only 0.05 ~ 0. 1s, so as to ensure that it can be used in the test-bed automation system. When the valve opens and closes quickly, it has no influence on the operation.
(3) The ball valve has good sealing performance.
Most ball valve seats are made of elastic materials such as PTFE, and the sealing pair composed of metal and nonmetal materials is usually called soft seal. Generally speaking, the tightness of soft seal is easy to ensure, and the requirements for machining accuracy and surface roughness of sealing surface are not very high.
(4) The ball valve has a long service life.
Due to the good self-lubricating performance of PTFE, the friction and wear between PTFE and ball are small, and the roughness is reduced due to the improvement of ball processing technology, thus improving the service life of ball valve.
Comparison between copper ball valve and stainless steel ball valve
1, the materials they chose are completely different. Copper ball valves are made of copper and stainless steel ball valves are made of stainless steel.
2. The copper ball valve has excellent corrosion resistance, smooth and labor-saving switch operation and no leakage. Stainless steel will not be corroded, pitted, rusted, worn and resistant to high temperature. Usually stainless steel is more expensive.
3. Under the same pressure, the quotation in stainless steel is cheap, and the medium temperature of copper ball valve is much higher than that of stainless steel ball valve. If the medium temperature is too high, it is necessary to use copper ball valve. If the medium temperature does not exceed 80 degrees, a stainless steel ball valve can be used.