What Is a Flow Control Valve?

Flow control valve, also known as 400X flow control valve, is a multi-function valve that uses high-precision pilot mode to control flow. Applicable to pipelines that need to control the flow and pressure of the distribution pipe, keep the predetermined flow constant, limit the excessive flow to a predetermined value, and appropriately reduce the high pressure upstream, even if the pressure upstream of the main valve changes, it will not affect Flow downstream of the main valve. The connection method is divided into flange type and thread type; welding type. Control and adjustment methods are divided into automatic and manual.

The flow control valve is a valve that controls the flow rate of the throttle port by changing the size of the fluid resistance of the throttle port under a certain pressure difference, thereby adjusting the moving speed of the actuator (hydraulic cylinder or hydraulic motor). mainly include

It can be selected according to the equal diameter of the pipeline, and it can be selected according to the maximum flow and the flow range of the valve.

Flow control valve, also known as 400X flow control valve, is a multi-function valve that uses high-precision pilot mode to control flow. Applicable to pipelines that need to control the flow and pressure of the distribution pipe, keep the predetermined flow constant, limit the excessive flow to a predetermined value, and appropriately reduce the high pressure upstream, even if the pressure upstream of the main valve changes, it will not affect Flow downstream of the main valve.

The flow control valve mainly includes a throttle valve, a speed regulating valve, an overflow throttle valve and a diverter header. This valve is generally installed horizontally.

Flow control valve, also known as 400X flow control valve, is a high-precision pilot

Can be selected according to the pipe diameter.

Can be selected according to the maximum flow and the flow range of the valve.

Medium temperature: 0-150 ° C;

Working temperature: 150 ° C;

Working pressure: 1.6MPa;

Working pressure difference: 20-600KPa;

Flow accuracy: 5%.

BodyQuality

See below:

The structure of digital flow control valve is composed of automatic spool, manual spool and display. The display part consists of a flow valve movement, a sensor transmitter, and an electronic calculator display.

Its work is extremely complicated. The measured water flows through the valve, and the water impinges on the impeller in the flow core. The rotation of the impeller and the sensor send the sensor to make the sensor send a signal proportional to the flow. The flow signal is sent to the electronic calculator through the wire. After calculation and microprocessor processing, its flow value is displayed.

The manual spool is used to adjust the flow rate, and the required flow rate value is set according to the displayed value. The automatic spool is used to maintain a constant flow, that is, when the pressure of the pipe network changes, the automatic spool will automatically open the large fire and close the small valve port under the pressure to maintain the set flow value unchanged.

1 pressure-temperature degree

The pressure of the flow control valve-the temperature level is determined by the pressure of the housing, the internal parts and the material of the control pipe system-the temperature level. The maximum allowable working pressure of the flow control valve at a certain temperature is the smaller of the maximum allowable working pressure of the housing, internals and control pipe system materials at that temperature.

1.1 The pressure of the iron casing-the temperature level should meet the requirements of GB / T17241.7.

1.2 The pressure of the steel casing-the temperature level should meet the requirements of GB / T9124.

1.3 For GB / T17241.7 and GB / T9124 materials that do not specify a pressure-temperature level, they can be in accordance with the relevant standards or design requirements.

Valve body

2.1 Valve body flange: The flange should be integrally cast with the valve body. The type and size of iron flanges shall comply with the requirements of GB / T17241.6, and the technical conditions shall comply with the requirements of GB / T17241.7; the type and dimensions of steel flanges shall comply with the requirements of GB / T9113.1, technical conditions Should meet the requirements of GB / T9124.

2.2 The length of the valve body is shown in Table 1.

2.3 Minimum wall thickness of the valve body The minimum wall thickness of the cast iron valve body should comply with the requirements of Table 3 in GB / T13932-1992, and the minimum wall thickness of the cast steel valve body should meet the requirements of Table 1 in JB / T8937-1999.

3 bonnet diaphragm seat

3.1 The connection type between the valve cover and the diaphragm seat, and the diaphragm seat and the valve body shall be flange type.

3.2 The number of connecting bolts between diaphragm seat and valve body shall not be less than 4.

3.3 The minimum wall thickness of the bonnet and diaphragm seat is in accordance with the requirements of 2.3.

3.4 The flange of the valve cover and the diaphragm seat shall be round. The type of flange sealing surface can be flat, convex or concave-convex.

4. Stem, slow-closing valve plate, main valve plate

4.1 Slow-closing valve plate and valve stem should be connected tightly and reliably.

4.2 The seal type of slow-closing valve plate and main valve plate shall adopt the type of metal seal.

4.3 The main valve plate and valve stem must slide flexibly and reliably.

4.4 The sealing of the main valve plate and the main valve plate seat can adopt two types of metal seal and non-metal seal.

5 diaphragm

5.1 The performance of the diaphragm should meet the requirements of Table 2 (see next page).

5.2 The appearance quality of the diaphragm should meet the requirements of HG / T3090.

5.3 When applied to domestic drinking water, the safety of the diaphragm material should meet the requirements of GB / T17219.

6 Control pipe system

Each component of the control pipe system should be able to withstand the highest working pressure of the valve, and no leakage should occur in each part.

7 Materials

7.1 The selection of materials for main components should be in accordance with the provisions of JB / T5300.

7.2 Copper alloy castings shall comply with GB / T12225; gray cast iron castings shall comply with GB / T12226; their tensile strength shall not be less than 200MPa; ductile iron castings shall comply with GB / T12227; carbon steel castings shall meet GB / T12229; Austenitic steel castings shall meet the requirements of GB / T12230.

Rare earth giant magnetostrictive material (455) is another important new functional material after rare earth permanent magnet, rare earth luminescent and rare earth high temperature superconducting material. Under the action of a certain magnetic field, the material has a much larger length or volume change compared to traditional nickel-based or iron-based magnetostrictive materials, hence its name. Because of its excellent properties, giant magnetostrictive materials have been widely used in fluid control valves. Recently, with the improvement of material preparation technology and the research of magnetostrictive mechanism, the introduction of various advanced control technologies has opened up space for the development and application of giant magnetostrictive materials. As for fluid control valves, The development of a new type of magnetostrictive material replaces the traditional force feedback electro-hydraulic servo valve torque motor, so it is also possible to develop new two-stage or even multi-stage electro-hydraulic servo valves. High-frequency on-off valves have also become the direction of further application of materials ^[1] .