Differential Pressure Control Valves

Share to

Return to List

1. How does a differential pressure control valve work?

A differential pressure control valve is a device used to control pressure differences in a fluid system. Its operating principle is usually based on the following key steps:

●Detect the differential pressure: The differential pressure control valve has an internal diaphragm sensor that detects the pressure difference between two different locations in the system in real time.

●Compare the set value: The detected differential pressure is compared with the preset target differential pressure value.

●Control flow: When the detected differential pressure deviates from the set value, the control valve will automatically adjust the valve opening. If the differential pressure is too large, the valve will reduce the opening and restrict the fluid flow, thus reducing the differential pressure; conversely, if the differential pressure is too small, the valve will increase the opening and increase the fluid flow to increase the differential pressure.

For example, in the heating system, the differential pressure control valve can ensure that the pressure difference between different branches is kept within a reasonable range, thus realizing uniform heating in each branch.

In specific design and application, the structure and working method of differential pressure control valves may vary, but in general they all revolve around the basic principle of detecting differential pressure, comparing the set value and controlling the flow rate to realize their functions.

2. What are the factors to consider when choosing a differential pressure control valve?

●System Parameters

Flow range: Know the maximum and minimum flow rates expected in the system to ensure that the selected valve can effectively control differential pressure over the entire flow range. Working Pressure: Determine the normal working pressure of the system and the maximum pressure that may occur, and select a differential pressure control valve that can withstand the corresponding pressure.

●Valve material

According to the nature of the fluid in the system (e.g. corrosiveness, temperature, etc.), select the appropriate valve body and spool material to ensure the durability and reliability of the valve.

●End connection

Consider the connection types with the pipeline, such as threaded connection, flange connection, etc., to match the pipeline system.

●Quality

Choose products with good reputation, usually its quality and after-sales service is more guaranteed.

●Installation and maintenance convenience

Selecting differential pressure control valves with simple structure and easy installation and maintenance can reduce the operation cost in the later stage.

●Environmental conditions

Consider the temperature, humidity, vibration and other factors of the installation environment to ensure that the valve can work properly in that environment.

Considering the above factors together can help you select a proper differential pressure control valve that suits the needs of your particular system.

3. Taloar differential pressure control valves' unique design features

① Product features of Taloar’s PC320:

●Relying on the pressure change of the high/low pressure chambers to change the valve opening angle, automatically keeping differential pressure constant.

●Large controllable pressure differential range.

●Valve shut-off function.

●Differential pressure value can be set on site.

●Pressure measuring connections on both side.

●Vent hole in high pressure chamber.

●Lower noise.

② Product features of Taloar’s PC1000:

●Relying on the pressure change of the high/low pressure chambers to change the valve opening angle, automatically keeping differential pressure constant.

●Low-resistance Y-shaped structure.

●Large controllable differential pressure range.

●Differential pressure value can be set on site.

●Memory limit function.

●Vent hole in High Pressure chamber.

●Lower noise.

4. What are the significant differences between differential pressure control valves and static balancing valves?

Differential pressure control valve is a kind of dynamic balancing valve, which will automatically adjust the opening degree according to the system changes, so as to realize the dynamic balance of variable flow system.

●Installation position

Differential pressure control valve: they can only be installed in the return pipe, the water supply pressure signal through the pilot copper pipe from the water supply pipe.

Static balancing valve: they are usually installed in the return pipe when used alone, especially in the high temperature loop, because the measurement results are more accurate. When used with differential pressure control valves, they are recommended to be installed in the water supply pipe to save installation space. Meanwhile, the static balancing valves can also provide a contact point for the pressure-guiding copper pipe of the differential pressure control valve to avoid unnecessary waste of extra holes in the pipeline, and reduce the leakage point.

●Working principle

Differential pressure control valve: Differential pressure control valves can automatically change the resistance coefficient according to the change of system working condition (differential pressure), within a certain range of differential pressure, the flow rate through can be effectively controlled to maintain a constant value.

Static balancing valve: Static balancing valves, by changing the spool and seat gap (opening), to change the flow resistance through the valve, achieve the purpose of regulating the flow. When used in conjunction with differential pressure control valves, they help to set the correct working point of differential pressure control valves.

●Application effect

Differential pressure control valve group: it can make the end equipment flow changes are not affected by system pressure fluctuations. Flow changes do not interfere with each other. Compared with the traditional system, it can save energy 7% to 20%; greatly shorten the commissioning time. What’s more, the system operates with high efficiency and regulation of temperature accuracy is higher.

Static balancing valve: variable flow system only applies static balancing valves, because they can meet the design requirements and have a small amount of energy saving effect on the system. But when operating at partial load, the system energy saving is not ideal, and at the same time, the overflow generated by the system at partial load will lower the return temperature and affect the efficiency of the system.

5. What are the applications of differential pressure control valves?

Differential pressure control valves are used in applications where real-time flow adjustments are required to maintain system balance.

Major applications include:

HVAC systems: In large commercial buildings or complex air conditioning systems, differential pressure control valves can automatically adjust the flow rate of individual circuits or motorized control valves to ensure comfort and system efficiency in each zone.

Industrial processes: In industrial piping systems, differential pressure control valves automatically adjust flow to cope with load fluctuations in the production process, maintaining system stability and efficiency.

Overall, differential pressure control valves are suitable for use in systems with large load variations and high demand for flow adjustment, providing real-time automatic adjustment to ensure optimal system operation. A smooth-running system can lead to greater energy savings. And because the points are independent of each other, they are especially suitable for projects built in phases.