National standard and German standard globe valves and gate valves

Don't change. Although the structural length of the national standard is mostly the same as that of the German standard. However, the national standard valve body is not up to the export requirements. It is recommended to find a foundry with a German standard model to purchase valve body processing.

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.

No, it will affect the quality of the application, and then people will think that the quality of the valve in your factory is unstable, which is troublesome.

Let's analyze in detail what is the German standard check valve, the standard of the German standard check valve, the performance of the German standard check valve, if the answer is helpful to you, please raise your noble hand, give the answerer the American Weidun VTON valve a like!

Imported check valve products, there are German standard, American standard, British standard, and the national standard produced in China, many users are not very clear about the difference between these standards, improper selection caused by the wrong size, can not be installed and used, so this article introduces the German standard check valve.

German standard check valve refers to the check valve that adopts German or European manufacturing standards for all materials, connection sizes, testing and inspection standards and valve parameter identification in the production and manufacturing. For example, the imported lifting check valve of the American Weidun VTON German standard.

DIN3202-F4 F5 F7 check valve is suitable for liquid, gas and water medium pipelines and equipment, as a connection and break for flow change. The fluid resistance of the valve and the torque required for opening and closing are small, not limited by the flow direction of control, the shape is relatively simple, and the manufacturing process is good. Therefore, it has a wide range of uses, and is widely used in food, medicine, water supply and drainage engineering, construction, fire protection and other fields.

German standard check valve design standard: DIN3352

German standard check valve structure length: DIN3202

German standard check valve connection flange: DIN2543-2545

German standard check valve test and inspection: DIN3230

Product Model: Product diameter: DN15 200mm

Manufacturing standard: DIN3356

Structure length: DIN3202

Flange standard: DIN2543-2545 butt weld standard: DIN3239 test standard: DIN3230

The opening and closing parts of the national standard 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. Gate valve is a kind of valve with a wide range of use, the shut-off device with a general diameter of dn 50mm is selected from it, and sometimes the shut-off device with a very small diameter is also selected with two sealing surfaces of the gate valve gate, and the two sealing surfaces of the most commonly used mode gate valve form a wedge, and the wedge-shaped angle varies with the valve parameters, usually 50, and 2 ° 52 when the medium temperature is not high' 。The gate plate of the wedge gate valve can be made into a whole, which is called a rigid gate; It can also be made into a ram that can produce a slight amount of deformation to improve its manufacturability and make up for the deviation of the sealing surface angle in the processing process, which is called elastic ram.

Gate valve is the main control equipment for the flow or conveying volume of powder, grain, granular and small materials, and is widely used in metallurgy, mining, building materials, food, chemical and other industries to control flow changes or quickly cut off.

The national standard gate valve specifically refers to the type of cast steel gate valve, which can be divided into wedge gate valve and parallel gate valve according to the sealing surface configuration, and the 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.

When the national standard gate valve is closed, the sealing surface can only rely on the medium pressure to seal, that is, the sealing surface of the ram is pressed to the valve seat on the other side by relying on the medium pressure to ensure the sealing of the sealing surface, which is self-sealing. Most gate valves are forcibly sealed, that is, when the valve is closed, the ram should be forcibly pressed to the valve seat by external force to ensure the tightness of the sealing surface.

The gate plate of the national standard gate valve moves in a straight line with the valve stem, which is called the lifting rod gate valve (also known as the open rod gate valve). Usually there is a trapezoidal thread on the lifting rod, through the nut at the top of the valve and the guide groove on the valve body, the rotary motion is changed into linear motion, that is, the operating torque is changed into operating thrust.

When the valve is opened, when the ram lift height is equal to 1:1 times the valve diameter, the flow of the fluid is completely unobstructed, but this position cannot be monitored during operation. In actual use, it is marked by the apex of the valve stem, that is, the position that cannot be opened, as its fully open position.

In order to account for the lock-up phenomenon of temperature changes, it is usually rewound 1 2-1 turns back to the vertex position as the position of the fully open valve. Therefore, the fully open position of the valve is determined by the position of the ram (i.e. the stroke).

Some gate valves, the stem nut is located on the gate, and the handwheel rotates to drive the valve stem to rotate, and the gate is lifted, this kind of valve is called a rotary rod gate valve or a dark rod gate valve.

A gate valve is a valve in which the shut-off (ram) moves in the vertical direction along the centerline of the channel. The gate valve can only be used for full opening and full care in the pipeline, and cannot be used for adjustment and throttling. Gate valve is a kind of valve with a wide range of use, generally the diameter of DN 50mm shut-off device is used for it, sometimes the diameter of the shut-off device is also used gate valve.

When the national standard globe valve is opened, the opening height of the disc is 25% of the nominal diameter When 30%, the flow rate has reached the maximum, indicating that the valve has reached the fully open position. Therefore, the fully open position of the globe valve should be determined by the stroke of the disc.

The national standard globe valve is a forced sealing valve, so when the valve is closed, pressure must be applied to the valve disc to force the sealing surface not to leak. When the medium enters the valve from the bottom of the valve disc, the resistance that needs to be overcome by the operating force is the friction between the valve stem and the packing and the thrust generated by the pressure of the medium, and the force of closing the valve is greater than the force of opening the valve, so the diameter of the valve stem should be larger, otherwise the failure of the top bend of the valve stem will occur.