What matters need to be paid attention to when purchasing valves

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.

First, what to pay attention to when purchasing valves:

1.The first is, of course, the appearance of the valve. When purchasing, visually inspect the valve, and the surface should be free of trachoma; The surface of electroplating should be glossy and uniform, and attention should be paid to whether there are defects such as peeling, cracking, burning, exposed bottom, peeling, black spots and obvious pitting; The surface structure of the spraying should be fine, smooth and uniform, and there should be no defects such as sagging and exposed bottom.

The above defects will directly affect the service life of the valve.

2.The connection of the valve is also something to consider. The pipe thread of the valve is connected with the pipeline, and the surface of the thread is visually inspected for obvious defects such as dents and broken teeth when purchasing, and special attention should be paid to the effective length of the pipe thread and the connector will affect the reliability of the seal, and the effective length of the pipe thread should be paid attention to when purchasing.

Generally, the effective length of the cylindrical pipe thread of DN15 is about 10mm.

3.Gate valves and ball valves are generally marked with nominal pressure on their valve bodies or handles, and they can be selected according to their own needs when purchasing.

4.When replacing an existing gate valve or ball valve, it is necessary to find out the length of its structure so that it cannot be installed after purchase.

5.There are two kinds of pipe threads for triangle valves: internal threads and external threads, which should be purchased according to needs; It should also be noted that there are some zinc alloy triangle valves on the market, which are sold at a lower price than ordinary products, but are prone to corrosion and fracture.

2. Pay attention to the packing when choosing the valve: the way to eliminate the leakage of the packing is:

Correct selection of fillers;

Reload according to the correct one;

If the valve stem processing is unqualified, it should be repaired or replaced, and the surface finish should be at least 5, and more importantly, it should reach more than 8, and there should be no other defects;

Take protective measures to prevent corrosion, and replace those that have been corroded;

The stem bend should be straightened or renewed;

After the filler is used for a certain period of time, it should be replaced;

The operation should be paid attention to smoothly, open and close slowly, and prevent drastic temperature changes or medium impact.

1. What is the control function of the valve? Each valve structure is designed to perform a certain function. Don't expect one valve to do all the functions within the entire piping system.

2. Pressure-temperature rating. In order to meet the actual needs, pay special attention to the pressure-temperature rating of the required valve. Particular attention should be paid to the sealing and gasket materials, which determine the pressure-temperature rating of the valve to a considerable extent.

Specify sealing materials and sedimentation materials to meet or exceed actual needs.

3. Valves and connections. Factors such as the integrity of the piping system, future routine maintenance, corrosion protection, on-site assembly, weight and safety are all factors that should be considered in determining the way the valve is connected to the pipe.

4. The operation mode or operation method is selected according to the valve type, size, pressure, temperature, installation environment and other factors.

5. When ordering valves, please provide the following data to avoid unnecessary repetition and delay, and ensure that the purchased valve is indeed the valve you need.

1) Valve diameter.

2) Pressure interface material: casting and component material.

3) Types of valves: imported valves, ball valves, needle valves, globe valves, gate valves, check valves, butterfly valves, etc.

4) Terminal connection mode, if the connection mode is welding, the thickness of the pipe wall should also be provided; If the connection is flanged, the flange surface or polish should be provided.

5) Any material that is different from the standard configuration: sealing material, precipitation material, bolt material, etc.

6) Any accessories: anti-acid protective layer, locking device, chain operation, etc.

7) Manual or power actuator: please include the required technical details.

Threaded valves are usually fitted with atmospheric low pressure above. If it is to be used on high-pressure valves, it is not available, and it is necessary to use a welded link valve or a flanged connection valve.

Before purchasing and using, please determine the working pressure and medium range of the valve, and then consult the technical department of the professional valve manufacturer for selection.