Valves Commonly Used in Chemical Production
Sep 20, 2023
As the pace of scientific and technological development further accelerates, chemical production is gradually becoming intelligent and automated. In chemical production equipment, a valve is a very important component. There are many types of valves with different functions. During the design process of the chemical system, the valves must be reasonably selected according to the specific requirements of the system to ensure that the functions of the valve can be effectively exerted, thereby laying a solid foundation for the safe and stable operation of the production system and ensuring that chemical enterprises can create higher economic benefits.
1. Types of valves
In the chemical production process, many types of valves are involved, such as ball valves, diaphragm valves, butterfly valves, gate valves, etc. Only by fully understanding the functions of valves can we select a more reasonable valve to a certain extent to meet the requirements for chemical production.
1.1 Ball valves
The ball valve is a quarter-turn valve, which has the characteristics of small sizes, small strokes, fast response speeds, well closing, reliable operation, small installation space, and simple installation and maintenance. Usually, ball valves are used in chemical control environments with high viscosity, low temperature and high pressure. Ball valves are difficult to manufacture and process, and the price is high, especially large-diameter ball valves. Therefore, it is necessary to fully consider the characteristics of the ball valve so that the functions of the ball valve can be maximized in the process of selecting a ball valve.
1.2 Globe valves
In chemical pipelines, if the internal temperature is too high, you can choose a globe valve, because the globe valve can not only give full play to the functions of small valves but also transmit steam. In chemical pipelines with relatively small diameters, globe valves can reasonably control the flow and pressure in chemical pipelines, and have good application effects. However, the globe valve cannot be used in low vacuum chemical control environments, and it cannot be used as a vent valve. In addition, the medium in chemical pipelines has high viscosity or is in a suspended state, so globe valves cannot be used.
1.3 Diaphragm valves
Compared with other types of valves, the structure of the diaphragm valve relies on a soft plastic membrane or rubber membrane to control fluid movement. Diaphragm valves have relatively small fluid resistance and can be closed in both directions. They are usually used in corrosive, low-pressure suspended viscous fluid media or slurries. There is no close relationship between the operating mechanism and the medium channel, and the fluid is blocked by the elastic diaphragm. The temperature resistance of the diaphragm material determines the application temperature of the diaphragm valve.
1.4 Gate valves
The gate valve is a straight-stroke valve with mature technology, reliable operation, low price, and good closing. However, it has a large size and is tall, requiring large installation space and maintenance auxiliary facilities. The valve stem has a long stroke and takes a long time to close. Gate valves are divided into single wedge gate valves and double wedge gate valves according to the wedge type and cutting method. A gate valve is suitable for pipelines containing solid particles, residues or media that are easy to crystallize and solidify.
1.5 Butterfly valves
A butterfly valve is a valve with simple structure. Butterfly valves can be used to control the flow of various media such as air, water, steam, various corrosive media, mud, oil, liquid metal and radioactive media. They mainly play the role of cutting off and throttling pipelines. The butterfly valve core is a disc-shaped butterfly plate that rotates around its axis in the valve body to achieve the purpose of opening and closing or adjustment. Butterfly valves are suitable for opening, closing and regulating ventilation and dust removal pipelines, and are widely used in gas pipelines and waterways in power and petrochemical systems.
1.6 V-shaped ball valves
The ball core of the V-shaped ball valve is a 1/4 spherical shell with a V-shaped notch. It has a large flow capacity, a large adjustable range, shear force, and can be closed well. It is especially suitable for working conditions where the fluid material is fibrous. The edge of the valve core is V-shaped, and there is a V-shaped opening on the ball. As the ball rotates, the change in the middle opening area can be used to adjust the flow rate and can cut off the impurities contained in the fluid and close it. It is suitable for controlling pulp, mortar and viscous fluids.
1. Types of valves
In the chemical production process, many types of valves are involved, such as ball valves, diaphragm valves, butterfly valves, gate valves, etc. Only by fully understanding the functions of valves can we select a more reasonable valve to a certain extent to meet the requirements for chemical production.
1.1 Ball valves
The ball valve is a quarter-turn valve, which has the characteristics of small sizes, small strokes, fast response speeds, well closing, reliable operation, small installation space, and simple installation and maintenance. Usually, ball valves are used in chemical control environments with high viscosity, low temperature and high pressure. Ball valves are difficult to manufacture and process, and the price is high, especially large-diameter ball valves. Therefore, it is necessary to fully consider the characteristics of the ball valve so that the functions of the ball valve can be maximized in the process of selecting a ball valve.
1.2 Globe valves
In chemical pipelines, if the internal temperature is too high, you can choose a globe valve, because the globe valve can not only give full play to the functions of small valves but also transmit steam. In chemical pipelines with relatively small diameters, globe valves can reasonably control the flow and pressure in chemical pipelines, and have good application effects. However, the globe valve cannot be used in low vacuum chemical control environments, and it cannot be used as a vent valve. In addition, the medium in chemical pipelines has high viscosity or is in a suspended state, so globe valves cannot be used.
1.3 Diaphragm valves
Compared with other types of valves, the structure of the diaphragm valve relies on a soft plastic membrane or rubber membrane to control fluid movement. Diaphragm valves have relatively small fluid resistance and can be closed in both directions. They are usually used in corrosive, low-pressure suspended viscous fluid media or slurries. There is no close relationship between the operating mechanism and the medium channel, and the fluid is blocked by the elastic diaphragm. The temperature resistance of the diaphragm material determines the application temperature of the diaphragm valve.
1.4 Gate valves
The gate valve is a straight-stroke valve with mature technology, reliable operation, low price, and good closing. However, it has a large size and is tall, requiring large installation space and maintenance auxiliary facilities. The valve stem has a long stroke and takes a long time to close. Gate valves are divided into single wedge gate valves and double wedge gate valves according to the wedge type and cutting method. A gate valve is suitable for pipelines containing solid particles, residues or media that are easy to crystallize and solidify.
1.5 Butterfly valves
A butterfly valve is a valve with simple structure. Butterfly valves can be used to control the flow of various media such as air, water, steam, various corrosive media, mud, oil, liquid metal and radioactive media. They mainly play the role of cutting off and throttling pipelines. The butterfly valve core is a disc-shaped butterfly plate that rotates around its axis in the valve body to achieve the purpose of opening and closing or adjustment. Butterfly valves are suitable for opening, closing and regulating ventilation and dust removal pipelines, and are widely used in gas pipelines and waterways in power and petrochemical systems.
1.6 V-shaped ball valves
The ball core of the V-shaped ball valve is a 1/4 spherical shell with a V-shaped notch. It has a large flow capacity, a large adjustable range, shear force, and can be closed well. It is especially suitable for working conditions where the fluid material is fibrous. The edge of the valve core is V-shaped, and there is a V-shaped opening on the ball. As the ball rotates, the change in the middle opening area can be used to adjust the flow rate and can cut off the impurities contained in the fluid and close it. It is suitable for controlling pulp, mortar and viscous fluids.
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