A differential pressure control valve is an automatic regulating valve used to control pressure differentials in fluid systems. It is widely applied in industries such as HVAC, water supply and drainage, power generation, petrochemical, and pharmaceuticals. Its primary function is to maintain the pressure differential within a predetermined range to ensure proper system operation, preventing equipment damage and excessive energy consumption that may result from excessively high pressure differentials.
Working Principle
The basic working principle of a differential pressure control valve involves real-time monitoring and adjustment of the pressure differential within a system to automatically regulate the opening of the valve core based on fluid flow conditions, thereby controlling the flow rate through the valve and maintaining a stable system pressure differential.
A differential pressure regulator maintains constant pressure between two measurement points by responding to changes in system pressure difference. When the pressure differential at the system’s pressure taps changes, the capillary tube transmits pressure to displace the valve diaphragm, driving the valve cone to adjust its opening. This compensates for resistance variations and keeps the pressure differential unchanged between the two measurement points.
ΔPL=Circuit pressure drop at design flow rate
System pressure differential ΔPL acting on the diaphragm:
When PA increases causing ΔPL to rise, the pressure differential valve reduces its cone opening.
When PA decreases causing ΔPL to drop, the pressure differential valve enlarges its cone opening.
Functions of Differential Pressure Regulator
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Control flow
The differential pressure control valve can be connected with an regulating valve at pipe end to achieve flow control, prevent water shortage at the end of the system, improve the pump working efficiency and save energy.
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Reduce noise
The differential pressure control valve can maintain the differential pressure between the inlet and outlet of the control valve to avoid excessive differential pressure under partial loading conditions which will generate noise.
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Make hydraulic balance commissioning simpler
The differential pressure control valve can act as an independent and non-interfering water system module by coordinating with the piping networks. To control the flow of each system module, it is only needed to perform the commissioning once, which simplifies the hydraulic balance process, improves the differential pressure control precision,and greatly reduces the cost and time for hydraulic balance commissioning.
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Allow regional balance
The differential pressure control valve can set each pipe network system as an independent sectional module to be assembled into the main system. It is not needed to launch the hydraulic balancing commissioning again whenever there is expansion or a change in design in the main system.
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Keep differential pressure between both ends of control valve constant
The differential pressure control valve when used with electric-driven valve together, helps keep the differential pressure between both ends of the control valve constant, improve the control valve authority, and make the control valve more accurate and stable.
Application
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The differential pressure control valve when used with the
balance valve can stabilize the differential pressure between the water supply and return ends, eliminate the interference of pressure change in the system. Keeps the differential pressure between the balance valve and differential pressure control valve within a stable range, ensure no overflow or water shortage occurs to the balance valve at downstream of the return water.
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The differential pressure control valve can be treated as a system module. When any modules are added to or removed from the main system, no need to carry out hydraulic balance commissioning again for the entire system.
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The differential pressure control valve PDV adjusts the differential pressure ΔPO of the main system to a more stable and suitable pressure differential ΔPL.
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The balance valve BV1 is used for flow measurement and shut-off for maintenance, connected with capillary of the differential pressure control valve PDV.
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The balance valve BV2 at downstream of the return water, set Kv value controls the flow of each loop.
Use Occasion
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HVAC
Primarily used in air conditioning water systems to maintain constant pressure differentials across branch circuits in chilled and hot water systems, enhancing operational efficiency and reducing energy consumption.
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Water supply and drainage systems
In urban water supply and wastewater treatment systems, they ensure balanced pressure in pipeline networks to prevent water hammer effects.
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Petrochemical industry
In chemical process pipelines, pressure differential control valves precisely regulate fluid flow rates to ensure safe and stable operation of equipment.
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Power Industry
In cooling water systems and steam delivery systems, these valves adjust water supply or steam pressure to optimize power generation efficiency.
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Pharmaceutical Industry
In aseptic production environments, they maintain pressure differentials.
Installation
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The valves are designed with multiple external copper parts, please handle with care during transportation or installation to prevent the valves failing to operate due to damage in the pipes. Large-sized valves are designed with lifting screw holes (2½"~10" valves designed with two M12 screw holes on their shells).
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All valve bodies are casted with flow direction arrows. During installation, please ensure the medium flow directions in pipeline systems are consistent with the directions of the arrows.
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Each valve is affixed with a parameter nameplate to indicate the adjustable differential pressure range which should be consistent with the system differential pressure control valve.
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It is needed to reserve sufficient space at installation to facilitate future adjustment, setting and maintenance. A straight pipe should have the length at least 5 times the pipe diameter needed in front of the valve, and a straight pipe should have the length at least 2 times the pipe diameter needed behind the valve. After valve installation, check to ensure that the ball valve in the pipe line is opened, and that the ball valve for venting is closed.
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The installation and piping of the valve shall comply with the principle shown in the diagram on the right. △PO is branch external differential pressure and △PL is branch load differential pressure.
Taloar’s differential pressure control valves rely on their own pressure changes in the high and low pressure chambers to change the valve opening. The differential pressure is automatically stabilized without the need for an external power source. With a long-stroke adjusting spring, the differential pressure adjustment range is wide. Its adjustment performance is excellent, and the differential pressure value can be set in the field. It features Y-type structure design, full flow, low resistance, stable flow and easy to adjust, with high-pressure air chamber exhaust hole and two sides of the pressure measurement interface. A zigzag ball valve is fitted to the front of the measuring point for shut-off and service. Stainless steel fittings extend outside the insulation for easy measurement.
As a professional valve manufacturer, Taloar is dedicated to offering its customers the highest quality differential pressure control valve products on the market. Should you have any special customized products, please contact us.
If you need to keep up with innovations and technological advancements in differential pressure control valves, Taloar will support you! For more details, please contact sales@taloar.com or WhatsApp 008618112507128.
