Angle control valve of the rational use

Angle control valves are known for their simple flow path and low resistance, making them suitable for normal forward installation. However, under high-pressure drop conditions, it is recommended to install the valve in reverse to reduce unbalanced forces on the valve plug and minimize damage. This also helps improve media flow and prevents coking or clogging. When using an angle valve in reverse, it is crucial to avoid long-term operation at small openings, as this can cause severe vibrations and damage the spool. Especially during the trial phase of a chemical plant, where load is low and process conditions may not be fully met, it's best to avoid reverse installation to prevent unnecessary damage to the valve. Control valves play a vital role in automatic control systems, often referred to as the "hands and feet" of industrial automation. They consist of an actuator and a valve body. From a hydraulic perspective, they function as variable throttling elements that adjust flow by changing the drag coefficient based on input signals. The structure of an angle control valve is similar to a single-seat valve, except for its angular body. It features a simple flow path and low resistance, making it ideal for handling high-pressure drops, viscous fluids, and those containing suspended particles. This design helps prevent coking, sticking, and clogging, while also allowing for easy cleaning and self-purification. Normally, angle valves are installed in the forward direction, with the fluid flowing out from the bottom. However, in cases involving high pressure, high viscosity, or media prone to coking, reverse installation is advised. In this configuration, the fluid enters from the bottom, which improves balance and reduces wear on the valve plug. It also facilitates better flow for viscous or particulate-laden media, reducing the risk of blockage. A case study from Jilin Chemical Industry Co., Ltd., involving a German-imported acetaldehyde unit (PV-23404), demonstrated issues when the angle valve was used in reverse under high-pressure drop conditions. During water testing, the valve experienced strong vibrations and emitted loud noises, eventually leading to spool failure after 4 hours. While foreign experts initially suspected manufacturing defects, further analysis revealed that the issue stemmed from improper usage rather than quality problems. This highlights the importance of understanding how flow direction affects valve performance. Most control valves are asymmetric, and their flow characteristics are optimized for forward operation. When reversed, the flow capacity changes, and prolonged small opening operations can lead to instability due to unbalanced forces. Under normal operating conditions, the valve typically operates at a moderate opening, minimizing risks. In conclusion, angle control valves should generally not be used in reverse unless dealing with high-pressure, high-viscosity, or particulate-laden media. If reverse use is necessary, it is essential to avoid long-term small openings, especially during testing phases, to ensure safe and reliable operation.

Cryogenic Insulated Pipe Supports

Cryogenic Insulated Pipe Supports,Insulated Pipe,Insulated Pipe Clamp,Insulated Pipe Support

Simcan Industrial Equipment Co.,Ltd. , https://www.simcanindustry.com