NEWS-HENAN MF VALVE CO.LTD.

The difference between butterfly valves with and without pins

1. The basic structure and working principle of butterfly valves Butterfly valves are a commonly used fluid control valve, mainly composed of valve body, valve seat, valve disc and operating mechanism. The opening and closing parts of butterfly valves are butterfly plates. Its working principle is to control the flow of medium by rotating the valve disc, that is, when the valve disc rotates to a certain angle, the medium can pass through the flow channel between the valve body and the valve seat to achieve the purpose of controlling the flow. Butterfly valves are widely used in gas pipelines and waterways in metallurgy, light industry, electric power, petrochemical systems, etc. According to the different designs of the pin shaft, butterfly valves can be divided into two types: with pins and without pins. 2. The difference between butterfly valves with and without pins From the appearance, the most essential difference between pinned butterfly valves and pinless butterfly valves is whether there is a conical pin positioning on the valve plate. The connection method of penetrating the valve plate and the valve stem with a pin is a pinned butterfly valve, and vice versa is a pinless butterfly valve....

10/282024

Which valves are used for corrosive fluids?

1. Characteristics of corrosive fluids and hazards to equipment Corrosive fluids refer to liquids or gases with strong chemical properties that are easy to corrode equipment. They are widely used in chemical, petroleum, power and other industries. The hazards of corrosive fluids to equipment are mainly manifested as follows: ①Corrosion of pipeline walls and equipment surfaces, resulting in leakage, seepage and breakage; ②Reducing the life of equipment and increasing the cost of maintenance and replacement; ③May cause harm and pollution to the environment and human body. 2. Valve types and usage recommendations for corrosive fluids Choosing valve types and materials suitable for corrosive fluids is the key to reducing corrosion hazards. The following are valve types and usage recommendations for corrosive fluids: ①Plastic valves: Suitable for the control and regulation of corrosive fluids, with the advantages of corrosion resistance, acid and alkali resistance, etc. Common plastic valves include PVC valves, PP valves, PVDF valves, etc. ②Ceramic valves: Suitable for high temperature, high pressure, corrosive media, with high corrosion resistance and mechanical strength. Common ceramic valves include zirconia ceramic valves, silicon carbide ceramic valves, etc. ③ Stainless steel valves: suitable for general corrosive media, with high corrosion resistance and...

09/072024

Analysis of reasons and solutions for valves that are difficult to open and close

1. Valve sealing is not tight The most common reason for valves to be difficult to open and close is that the valve is not tightly sealed, resulting in blockage and jamming. This is caused by wear, deformation, corrosion, and other problems on the valve sealing surface during long-term use. Especially in industrial production, when multiple switches are used, the seal will be loose over time. Solution: For valves with severe sealing surface damage, it is necessary to replace the sealing surface or replace the valve. For valves with slight damage, valve maintenance technology can be used, such as replacing sealing gaskets, repairing valve sealing surfaces, etc. 2. Valve jamming The valve may be jammed by dirt, sediment, scaling or other substances during operation, hindering the normal operation of the switch. Solution: For valves that are jammed by dirt, cleaning, flushing and other methods can be used for treatment. For valves that are scaled during use, chemical treatment methods such as chemical cleaning and chemical dissolution can be used. 3. Improper selection of valve material The choice of material is also one of the common problems that make valves difficult to open and close. Different media, pressures,...

08/072024

Difference between wafer butterfly valve and flange butterfly valve

Butterfly valves are widely used. Common butterfly valves can be divided into two types: wafer butterfly valve and flange butterfly valve. Wafer butterfly valves do not have flanges. Common wafer butterfly valves have only four bolt holes. When installing, two flanges are needed to clamp the wafer butterfly valve in the middle, and then connect it to the pipeline through bolts. The wafer butterfly valve has a shorter structure length, smaller volume, and lighter weight, so it has advantages in small-diameter valves and has lower costs. Flange butterfly valve refers to a butterfly valve with two flanges. When installing, it is only necessary to match the flange holes on the flange butterfly valve with the flange holes on the pipeline one by one and connect them with bolts. Flange butterfly valves are suitable for large-diameter valves. As the diameter increases, the number of flange holes of the flange butterfly valve itself also increases accordingly, thereby providing better stability when connecting the pipeline. There are obvious differences between flange butterfly valves and wafer butterfly valves. 1. Installation method The flange butterfly valve is directly connected to the pipeline through its own flange, while the wafer...

07/222024

Common valve failures and solutions

Valve is a commonly used fluid control device that can control the flow, pressure, flow direction, temperature, etc. of the fluid. However, since valves often face various working conditions and environments, various failures often occur. Common valve failures and solutions: 1. Valve stuck: This is one of the most common valve failures. The reason may be that impurities such as sand, dirt or oxides in the valve block the valve stem, causing the valve to fail to open or close normally. The solution is to disassemble the valve, remove internal impurities, and lubricate the surface of the valve stem. 2. Valve leakage: This is another common valve failure. The reason may be that the valve seal is damaged or the gap between the valve stem and the valve body is too large, causing the fluid to leak out of the valve. The solution is to replace the seal or adjust the gap between the valve stem and the valve body. 3. Valve weakness: This failure is usually caused by overload or damage to the valve operating handle or motor. The solution is to check and replace the operating handle or motor. 4. Valve vibration: This failure is often...

06/182024

Nominal pressure, working pressure and design pressure of valves

1. What is the nominal pressure of valves? The nominal pressure of valves refers to the pressure level marked on the valve, which refers to the maximum pressure that the valve can withstand under standard test conditions. The nominal pressure of valves is usually expressed in standards such as PN, Class, ANSI, such as PN10, Class150, etc. 2. What is working pressure? Working pressure refers to the pressure that the valve withstands when it is actually working. In actual work, the pressure that the valve withstands is not only affected by the pressure of the medium, but also by factors such as the temperature, flow rate, and flow rate of the medium. 3. Design pressure The design pressure is the maximum pressure designed to ensure the safe operation of the equipment. When designing the equipment, the designer needs to consider the safety of the equipment and determine the maximum pressure value based on the actual use of the equipment. The design pressure is usually the theoretical upper limit of the pressure that the equipment can withstand. In actual use, it is best to control the working pressure of the equipment below the design pressure to ensure the...

05/212024