【Q&A Question 284】October 12, 2017
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【Q&A Question 284】October 12, 2017: What is the purpose of setting a control valve to air-open or air-close mode? (Unless otherwise specified, all questions and answers are based on hydrogenation units.) ) The answers to the daily questions change, and today’s answers are shown in subsequent questions. For management purposes, if you need to view content from a few days ago, please go through the summary post below. 2017 Q&A Summary Thread (updates have begun) http://bbs.hcbbs.com/thread-1657793-1-1.html 2017 Daily Question Summary Thread (updates have begun) http://bbs.hcbbs.com/thread-1657794-1-1.html 2016 Q&A Summary Thread (updates completed) http://bbs.hcbbs.com/thread-1597792-1-1.html (Source: Haichuan Chemical Industry Forum)
They are divided into gas-open and gas-close types, with safety considerations being the primary factor. In the event of an industrial accident (such as a loss of gas supply), it is necessary to determine whether the valve should be in an open or closed position. Generally, when controlling hazardous flow rates, a gas-open design is chosen; the valve closes in case of an accident to prevent accidents. For other protective measures, such as those involving cooling water, a gas-close design is used – the valve should remain open in the event of a gas supply interruption, otherwise overheating may occur, leading to equipment damage or explosions. When designing these systems, these two types are considered first, and only afterward is attention paid to the control mechanism of the controller (direct or reverse action).
Pneumatic control valves are divided into \"air-operated open valves\" and \"air-operated closed valves\". This classification is based on safety considerations: in the event of an industrial accident (such as a loss of air supply), it is important to know whether the valve should be in the open or closed position. Generally, when controlling hazardous flow rates, an air-operated open valve is preferred, as it ensures that the valve remains closed in case of an accident. For other protective purposes, such as cooling water systems, an air-operated closed valve is used; in the event of a loss of air supply, the valve should remain open to prevent overheating, equipment damage, or explosions
The so-called \"gas-driven on/off\" mechanism means that it operates when there is gas present, even without power; it shuts down when there is no gas. The \"gas-shut off\" mechanism is the opposite – it operates in the absence of both gas and power. The choice between gas-driven and gas-shut off operation is determined entirely based on considerations of process safety!
Pneumatic control valves are divided into \"air-operated open valves\" and \"air-operated closed valves\". This classification is based on safety considerations: in the event of an industrial accident (such as a loss of air supply), it is important to know whether the valve should be in the open or closed position. Generally, when controlling hazardous flow rates, an air-operated open valve is preferred, as it ensures that the valve remains closed in case of an accident. For other protective purposes, such as cooling water systems, an air-operated closed valve is used; in the event of a loss of air supply, the valve should remain open to prevent overheating, equipment damage, or explosions
Formed by the combination of the actuator’s reaction forces and those of the valve
Considering the safety of device production, efforts are made to minimize the risk of sudden gas supply interruption
Ensure the safety of the device in accident conditions and prevent accidents from occurring.
Pneumatic control valves are divided into \"air-open valves\" and \"air-close valves\"; this classification is based on safety considerations. In the event of an industrial accident (such as a loss of air supply), it is important to know what position the valve should be in – whether it should be open or closed. Generally, when controlling hazardous flows, air-open valves are preferred, as they ensure that the valve closes in case of an accident, thereby preventing hazards. For other protective purposes, such as those related to cooling water, air-close valves are used; in the event of a loss of air supply, the valve should remain open to avoid overheating, equipment damage, or explosions.
It is designed based on the wage requirements; for example, if this valve needs to be opened in an emergency, it is designed as a air-operated valve!
It is designed in accordance with the process requirements; for example, if this valve is to be opened in an emergency, it is designed as a air-operated shut-off type!