In automated process control systems, the regulating valve is a crucial and indispensable component, often referred to as the "hands and feet" of process automation. It is one of the terminal control elements in an automatic control system. The regulating valve consists of an actuator and a valve body. From a hydraulics perspective, the regulating valve is a throttling element with variable local resistance. It adjusts the valve opening based on input control signals, thereby altering the resistance coefficient to control the flow rate of the fluid.

1. Structure of Angle Regulating Valves

The body of an angle regulating valve features an angular design, with the remaining structure similar to that of a single-seat valve. Due to its simple flow passage design, the angle regulating valve offers low resistance, making it particularly suitable for regulating fluids with high pressure drops, high viscosity, and those containing suspended solids and particulate matter. This design helps reduce the occurrence of coking, adhesion, and clogging, and also facilitates cleaning and self-cleaning.

2. Usage Considerations of Angle Regulating Valves

(1) Medium Selection and Compatibility

Angle regulating valves are available in various materials, such as stainless steel, cast iron, and carbon steel. Different materials are suited to different media, so it is important to select the appropriate valve body and sealing materials based on operating conditions. For corrosive media, valves made from corrosion-resistant materials should be chosen to prevent leakage or failure due to corrosion of the valve body.

(2) Installation Position and Method

Angle regulating valves should be installed on pipelines where the fluid flow is steady, avoiding turbulence at the valve inlet. It is generally recommended to install the valve on a horizontal pipeline and keep the valve stem oriented vertically upward for easier maintenance and operation. If installed on a vertical pipeline, ensure that the fluid flows from top to bottom to utilize gravity to assist the media through the valve.

(3) Flow Direction and Pressure Differential Control

When installing angle regulating valves, ensure that the flow direction of the medium matches the directional arrow on the valve body to ensure proper valve operation. Additionally, be mindful that the pressure differential across the valve should not be too high, as excessive pressure differential may cause valve vibration, increased noise, or even damage to the valve core or seat. In conditions with high pressure differential, consider installing a pressure reduction device or a multi-stage control system to reduce the impact of pressure differential on the valve.

(4) Regular Maintenance and Cleaning

Over time, angle regulating valves may experience wear or clogging of the valve core and seat due to impurities or particulate matter in the medium. It is recommended to regularly inspect and clean the valve, particularly when dealing with media containing impurities or viscous substances. Regularly disassemble the valve and clean the internal components to ensure the valve’s sealing performance and regulating accuracy.

(5) Operational Considerations

When operating angle regulating valves, avoid suddenly opening or closing the valve, as this can cause fluid shock to the internal structure, leading to damage or wear. Adjust the valve opening slowly during operation, especially under conditions of high pressure differential and large flow rates, to ensure careful handling.

(6) Protective Measures

For angle regulating valves installed in outdoor or harsh environmental conditions, protective measures should be taken, such as adding rain covers, dust covers, or insulation layers to protect the valve from environmental impact. Additionally, for regulating systems handling flammable or explosive media, ensure that the valve’s explosion-proof rating and electrical connections comply with relevant standards to prevent safety accidents.

(7) Testing and Calibration

The regulating performance of angle regulating valves directly affects the stability of the process and the quality of the products. Therefore, it is recommended to regularly test and calibrate the valve’s regulating accuracy. Regular calibration helps to promptly identify and correct any deviations, ensuring efficient system operation.

(8) Emergency Handling

During operation, if any abnormalities are observed with the angle regulating valve (such as inability to regulate properly, leakage, or unusual vibrations and noise), operations should be immediately stopped, and the valve should be inspected and repaired according to the operating procedures. Untrained personnel should not attempt to disassemble or repair the valve themselves to avoid causing further damage or safety hazards.