Valve selection

Have you ever seen butterfly valves used? The pump inlets and outlets we supply for a Huadian power plant are all electric butterfly valves D941Y-16 DN600.

It is recommended to use butterfly valves, as gate valves have relatively more defects.

It depends on what medium you are transporting. It is better to use a gate valve for sealing.

You can't just look at the diameter, but also consider the medium, pressure, temperature and other conditions to decide which valve to use. If it is ordinary water, it is recommended to use a butterfly valve.

If you want to transport water or circulating water, you can choose a butterfly valve. If the materials being transported contain particles, you can choose a gate valve.

Due to the large diameter of the inlet and outlet pipes, manual valves are not easy to use. It is best to use electric or pneumatic ball valves.

Butterfly valves are suitable for mediums such as crude oil, oil products and water with large diameters and temperatures less than 80 degrees and pressures less than 1.0MPa. Gate valves are suitable for large diameters, steam, high-temperature oils, oil and gas and other media. They have good sealing performance and are not suitable for media that are prone to coking.

In addition, the previous design was based on the quality issues of butterfly valves.； The quality of modern butterfly valves has greatly improved, and they can largely replace gate valves. When selecting a valve, refer to the required parameters, which is absolutely fine.

If the medium is clean water, it is recommended to use a butterfly valve. If it is oil and gas, use a gate valve. If it is liquefied gas, use a ball valve.

If the transported medium is water, you can use a butterfly valve. Our oily sewage pump uses a butterfly valve at the inlet.

Please specify the fluid medium. Gate valves and butterfly valves have their own characteristics.

Steps and basis for selecting valves 1. Clarify the purpose of the valve in the equipment or device and determine the working conditions of the valve: Applicable medium, working pressure, working temperature, etc. 2. Determine the nominal diameter and connection method of the pipe connected to the valve: Flanges, threads, welding, etc. 3. Determine how to operate the valve: Manual, electric, electromagnetic, pneumatic or hydraulic, electrical linkage or electro-hydraulic linkage, etc. 4. Determine the materials of the selected valve shell and internal parts based on the medium transported by the pipeline, working pressure, and working temperature.: Gray cast iron, malleable cast iron, ductile iron, carbon steel, alloy steel, stainless acid-resistant steel, copper alloy, etc. 5. Select the type of valve: Closed-circuit valves, regulating valves, safety valves, etc. 6. Determine the type of valve: Gate valves, globe valves, ball valves, butterfly valves, throttle valves, safety valves, pressure reducing valves, steam traps, etc. 7. Determine the parameters of the valve: For automatic valves, first determine the allowable flow resistance, discharge capacity, back pressure, etc. according to different needs, and then determine the nominal diameter of the pipeline and the diameter of the valve seat hole. 8. Determine the geometric parameters of the selected valve: Structural length, flange connection form and size, height dimension of the valve after opening and closing, size and number of connecting bolt holes, external dimensions of the entire valve, etc. 9. Use existing data: Valve product catalogs, valve product samples, etc. Select the appropriate valve product

The choice of which valve to use still depends on the conveying medium, operating temperature, pressure, switching time, and action frequency. In the past, gate valves were usually used at the inlet and outlet of compressors, which had better sealing performance. At that time, butterfly valves were mainly centerline butterfly valves. However, with the development of three-eccentric metal-sealed butterfly valves, they can achieve zero leakage and can be closed quickly. In addition, their weight, volume and price are higher than those of gate valves. The valve has shown advantages. Therefore, there is a trend to replace the traditional application of gate valve. Of course, in some special occasions, the advantages of gate valve are still obvious, such as when the medium contains catalyst particles or coke particles, etc., gate valves are still used. Ball valves can also be used, but the price is much more expensive: hug:

I think it is more appropriate to use a butterfly valve! And future maintenance is also convenient! :) :) Some of the projects I do have butterfly valves at the inlet and outlet of the pump!

If you often use valve selection, I have standards here, which cannot be uploaded now. Leave your email address and I will send it to you, or QQ344353890

The characteristics of butterfly valve are: It has a simple structure, small dimensions and light weight, and is suitable for manufacturing valves with larger pipe diameters. Suitable for low pressure. The characteristics of gate valve are: The sealing performance is good, the fluid resistance is small, and the opening and closing force is small. It is widely used and has certain flow regulation performance. What medium is being transported? Generally, liquids are gate valves and gases are butterfly valves.

Why is the pump outlet diameter smaller than the inlet diameter? Is it the other way around?

Butterfly valves and gate valves can be used. Look at the use of frontline staff * Get used to it.

Butterfly valve or gate valve? DN350~400 is not too big, don’t think too much, just use the gate valve. Some butterfly valves don’t close tightly (of course, if you choose rubber-lined ones), if the valve doesn’t close, it will be troublesome to repair the pump!