EN CN
Home / Services / Pump Encyclopedia / Pump Knowledge / How is the regulating valve used in production?

How is the regulating valve used in production?

06 Jul 2022Email

The angle control valve has a simple flow path and low resistance, and is generally suitable for forward use (installation). However, in the case of high pressure drop, it is recommended to use the angle control valve in reverse, to improve the unbalanced force and reduce the damage to the valve core, and it is also conducive to the flow of the medium and avoids coking and clogging of the control valve. When the angle control valve is used in reverse, it should be avoided to open with a small opening for a long time, so as to prevent strong oscillation and damage to the valve core. Especially in the trial production stage of chemical plants, due to the low load during trial production and the design process conditions that cannot meet the requirements quickly, the angle control valve used in the reverse direction should avoid the opening of a small opening for a long time as much as possible to prevent The angle control valve is damaged.

In the automatic adjustment system of the production process, the control valve is an important and indispensable link, which is called the "hands and feet" of the automation of the production process, and is one of the terminal control components of the automatic control system. It is composed of actuator and valve. From a hydraulic point of view, the regulating valve is a throttling element whose local resistance can be changed. The regulating valve changes the resistance coefficient by changing the stroke according to the input signal, so as to achieve the purpose of regulating the flow.

 

1. Structure and use of angle control valve

1.1 The structure of the angle control valve

Except that the valve body is an angle type, the other structure of the angle control valve is similar to that of the single seat valve. Its characteristics determine that its flow path is simple and the resistance is small, which is especially beneficial for high pressure drop, high viscosity, containing suspended solids and particulate matter. Fluid regulation. It can avoid the occurrence of coking, sticking and clogging, and is also easy to clean and self-clean.

1.2 Comparison of forward and reverse use of angle control valve

Under normal circumstances, the angle control valve is installed in the forward direction, that is, the bottom enters and the side exits. Only in the case of high pressure difference and high viscosity, easy coking, medium containing suspended particles, it is recommended to install in reverse, that is, the material side enters and the bottom exits. The purpose of the reverse use of the angle control valve is to improve the unbalanced force and reduce the wear on the valve core, and it is also conducive to the flow of high-viscosity, coking-prone and suspended particulate-containing media to avoid coking and clogging.

2. Analysis of reverse use of angle control valve

In the acetaldehyde plant introduced by Jilin Chemical Industry Co., Ltd. from West Germany, the pv-23404 angle control valve is recommended to be used in reverse under the process conditions of high pressure drop. During the water linkage test, the angle-type regulating valve oscillated strongly and made a harsh noise, and the spool broke after 4 hours of test. At that time, foreign experts believed that the quality of the valve core was not good. The author believes that it is not a quality problem, but due to unreasonable use. The reasons for its fracture are analyzed below.

We know that at present, except for butterfly valves and diaphragm valves, which are completely symmetrical in structure, all other structures of regulating valves are asymmetrical. When the regulating valve changes the flow direction, the value of ) will change due to the change of the flow path. The normal flow direction of all kinds of regulating valves is the direction in which the spool is opened (forward use), and the manufacturer only provides the flow capacity value and flow characteristics in the normal flow direction. When the regulating valve is used in reverse, that is, when the fluid flows in the direction of closing the spool, the flow capacity of the regulating valve will increase. During the water linkage test run, the simulated process conditions cannot quickly reach the normal state, and the regulating valve is used in a small opening state for a long time, which will cause serious instability due to the effect of unbalanced force. Therefore, the regulating valve will generate strong vibration and make a harsh noise, which will cause the valve core to break quickly. Under normal process conditions, the opening degree of the regulating valve is moderate, and even a small opening degree is short-lived, so the regulating valve can be used normally and safely.

3. Conclusion

Under normal circumstances, the reverse use of the angle control valve is not recommended, and the reverse use is only recommended for media with high pressure difference, high viscosity, easy coking and suspended particles. When using it in reverse, it should be avoided to run with a small opening for a long time, especially during the test run.

Related Pump Knowledge
More Pump Knowledge
25 Nov 2022
In order to improve the operation efficiency of centrifugal pump, reduce the energy consumption of equipment....
Read more
25 Nov 2022
Multistage boiler feed pump is a common water supply equipment used in conjunction with the boiler....
Read more
25 Nov 2022
Magnetic pump sliding bearing materials are impregnated graphite, filled with PTFE, engineering ceramics and so on. ...
Read more
25 Nov 2022
The suction of the high viscosity metering pump does not rotate normally to the position of 100% stroke length....
Read more
Related Products
More
Split Case Pump
Split Case Pump
  • Capacity:60-33005m³/h
  • Head:0.95-30.2bar
  • Price:$2200-215000
Double Suction Pump
Double Suction Pump
  • Capacity:60-33005m³/h
  • Head:0.95-30.2bar
  • Price:$2200-215000
Single Stage Chemical Pump
Single Stage Chemical Pump
  • Capacity:5.5-2600m³/h
  • Head:1.6-25bar
  • Price:$4300-37000
End Suction Chemical Pump
End Suction Chemical Pump
  • Capacity:5.5~400m³/h
  • Head:0.42-12.5bar
  • Price:$560-9800
Need More Information?
Contact us for more details about our pump, solutions and services.
Contact ZB
Tel
0086 731 88192011
Leave a message
Name*
Tel
Email*
Area
Products
Split Case Pump
Metallurgy
Mining Industry
Urban Water Supply
Petrochemical
Light Industry
Electricity
Chemical Industry
Farmland Irrigation
Other
Provide your comments and questions.