Regulation in the production process automation systems, the control valve is an important and indispensable link in the production process automation called "hands" is the automatic control system, one of the terminal control elements.
Angle valve flow path simple, the resistance is small, generally apply to forward use (installation). However, in the high-pressure drop occasions recommended the use of reverse angle valve to improve the unbalanced force and reduce the damage to the valve core, but also conducive to the flow of media to prevent coking and plugging valve. Angle valve used in reverse, in particular, should avoid prolonged opening of the small opening to prevent damage caused by a strong oscillation valve core. Particularly in the chemical plant pre-production, production capacity due to the lower trial, design process conditions can quickly meet the requirement, the reverse angle valve used should be avoided whenever possible a longer time to open a small opening status, to prevent Angle valve damage.
Keywords: angle valve; reverse-use (installation); a small opening; easily damaged
Regulation in the production process automation systems, the control valve is an important and indispensable link in the production process automation called "hands" is the automatic control system, one of the terminal control elements. It is the executing agency and the valves of two parts. From the hydraulic point of view, regulating valve is a local resistance to changes in throttle component, regulating valve in accordance with the input signal by changing the stroke to change the drag coefficient, so as to achieve the purpose of regulating traffic.
Angle valve structure and the use of
An angle control valve structure of
Angle valve body except for the angle, the other structures and single-seat valves are similar, characterized by the decision of its flow path simple, small resistance, in particular, is conducive to high-pressure drop, high viscosity, containing suspended solids and granular the regulation of fluid substances. It avoids coke, bonded, and blockage phenomenon, but also easy to clean and self-purification.
2-angle valve is, reverse the use of more
Under normal circumstances, angle valve are used toward the installation, which at the end into the side. Only in the high-pressure differential occasions and high-viscosity, easy-coking, the case of medium containing suspended particulate matter, it recommended to install the reverse, that is material side into the bottom out. Angle valve used in reverse, the purpose is to improve the unbalanced force and reduce the wear and tear on the valve core, but also conducive to high-viscosity, easy-coking, and the flow of medium containing suspended particles to prevent coking and plugging.
Angle valve used in reverse, Analysis
Jilin Chemical Industrial Co., Ltd. imported from West Germany acetaldehyde devices, pv-23404-angle high-pressure regulating valve in the descending process conditions, it is recommended to use the reverse. Linkage test in the water, the angle valve produced a strong oscillation, and the issue of harsh noise, post-test 4h spool on the broken. Foreign experts were considered to be caused by poor manufacturing quality of the spool. I do not think quality issues, but because of the use of unreasonable result. The following analysis of the causes of its fracture.
We know that, with the exception butterfly valves and diaphragm valves are completely symmetrical in structure, all other structures of the control valve is asymmetrical. When the control valve to change flow direction, due to changes in flow path will cause) value changes. The normal flow of various types of control valve spool are open to the direction (positive use), production plant to provide normal flow only when the flow capacity) values and flow characteristics. When the regulating valve used in reverse, when both the fluid along the direction of flow to spool off when the flow control valve capacity will be increased. Water linkage test, the simulated process conditions can quickly reach the normal state, regulating valve in the long period of time in the state to use a small opening, due to the role of unbalanced force, there will be serious instability. So regulating valve will produce a strong shock and issued harsh noise, resulting in broken spool quickly. In normal conditions, the control valve opening is a moderate, even a small opening is also a short-lived, so the valve can be normally safe to use.
Conclusion
Under normal circumstances, angle valve not recommended used in reverse, only in high-pressure differential, high-viscosity, easy to coke, and medium containing suspended particles was recommended to use the reverse. Reverse use, should avoid long-running case of the small opening, especially when testing should pay attention.