A Brief Introduction to the Control Valve (Part 2)

May. 09, 2020

Eight, pneumatic three-way cut-off valve: generally used for flow path switching, with fast response speed, good sealing characteristics.

9, pneumatic wedge gate valve: used as an emergency cut-off valve, with high cutting performance, large air consumption.

Pneumatic cut-off ball valve: it has the characteristics of the simple flow path, small leakage, and minimum pressure loss. It is especially suitable for high viscosity, suspension, and other occasions with large air consumption.

Pneumatic cut-off butterfly valve: it has the characteristics of large flow capacity, small pressure loss, compact structure, large operating torque, excellent cut-off performance, and durability.

12. Self-operated regulating valve: it has the characteristics of simple structure, reliable operation, etc., and is used in situations where the flow rate changes little, the adjustment accuracy is not high, or the instrument air supply is difficult. There are internal pressure type and external pressure type, for the application of higher precision requirements, need to use the conductor membrane head to adjust, the device is used after the pressure of the stable valve.

High Pressure Control Valve China

High Pressure Control Valve China

13. Globe control valve china installation requirements

Before installation, the control valve shall be inspected for strength test, stroke test, airtightness test and leakage test.

The control valve shall be installed vertically and vertically on the horizontal pipeline, and the control valve with a diameter greater than 50mm shall be provided with a permanent bracket.

The installation position should be convenient for operation and maintenance. If necessary, a platform should be set up and enough space should be left for maintenance at the upper and lower parts of the control valve.

Control valve set includes front and rear cut off valve, discharge valve, bypass valve, etc., its piping should be combined compact, easy to operate, maintain, and drain. The front and rear cutting off valve play a cutting off role can choose ball valve, gate valve; Bypass valve manual operation can choose the globe valve, ball valve; The discharge valve is used for the maintenance of control valves or the emptying of the pipeline and valve fluid when the valve is stopped. It is also used for the external fluid to flush the inside of the valve and the pipeline.

Should be away from continuous vibration equipment, when installed on vibration occasions should be anti-vibration measures.

When used in places with high viscosity, easy solidification, and high temperature, heat preservation or heat companion measures should be taken; Cold protection measures should be taken when used for low-temperature fluids.

For slurry, high viscosity fluids should be equipped with flushing lines.

The high pressure control valve China cannot be installed in the reverse direction, otherwise, it will affect the regulating flow characteristics and may damage the control valve.

14. Operation and shutdown of the control valve

Before the control valve is put into use, check whether its installation meets the requirements, whether the system debugging is qualified, whether the pipeline is blown clean, and whether the pressure test has been completed.

During the solvent test run, take the bypass first, and open the control valve fully after washing for a certain period of time. It can be put into normal use after being put into operation for a certain period of time.

When the control valve is out of service, open the blowdown valve to clean the medium that is prone to scaling, and clean the medium that is prone to solidification with low-pressure steam or factory wind to sweep the line, so as to ensure that there is no scaling and no residual solid impurities in the valve.

The sequence of the opening list of a self-operated regulating valve: close bypass valve → check the pressure behind the valve should be less than the set pressure behind the valve → slowly open the self-operated regulating valve before the stop valve → opens the self-operated regulating valve after the stop valve.Stopwatch sequence: close the front and backstop valves of the self-operated regulating valve → open the bypass valve.