A current-limiting check valve is a valve that integrates flow limiting and backflow prevention functions. It is primarily used to control the flow rate of fluids (such as water and gas) and prevent backflow. It is widely used in industrial, construction, and municipal applications, playing a crucial role, especially in scenarios requiring simultaneous flow regulation and backflow prevention.
This valve adopts an integrated pilot valve-main valve structure, supporting stepless head adjustment from 0.1-0.6MPa (factory default 0.1MPa), and is suitable for media temperatures from 0-150℃. It automatically detects the pump head and dynamically adjusts the valve opening: when the head is below the set value, the valve closes to increase the head; when it is above the set value, it fully opens to reduce resistance and maintain efficient pump operation. The backflow prevention function uses low-resistance slow-closing technology to achieve zero backflow and no closing noise. It can be installed horizontally or vertically. Commissioning requires adjustment of the outlet pressure using a pressure regulating valve, and it is equipped with an external pressure guide pipe and filter maintenance device.
Core Functions
Flow Limiting Function
Through a built-in throttling device (such as an orifice plate or adjustable valve), the maximum flow rate of the fluid is limited to prevent system pressure fluctuations or equipment damage caused by excessive flow.
For example, in a water supply system, the flow limiting function can prevent water hammer (the impact force caused by a sudden stop or reverse flow of water), protecting pipelines and equipment.
Check Valve Function
Allows unidirectional fluid flow. When the fluid flows in the opposite direction, the valve automatically closes to prevent backflow.
For example, installing a check valve at the pump outlet can prevent water backflow when the pump stops, which could cause pump reversal or damage.
Working Principle
Flow Limiting Section: Controls the cross-sectional area through which the fluid passes via a throttling orifice or adjustable valve, thereby regulating the flow rate.
Check Valve Section: Utilizes gravity, a spring, or fluid pressure difference to open the valve disc during forward flow and close it during reverse flow.
Combined Design: The flow limiting and check valve functions are usually integrated into a single valve body, resulting in a compact structure and easy installation.
Main Types
Fixed Flow-Limiting Check Valve
Fixed flow-limiting orifice diameter, limited flow adjustment range, suitable for scenarios with stable flow demand.
Example: Pressure stabilizing valve in fire protection systems, limiting water flow velocity to maintain system pressure.
Adjustable Flow-Limiting Check Valve
Dynamically adjusts flow rate by manually or electrically adjusting the valve opening.
Example: Adjusting cooling water flow according to load changes in air conditioning water systems.
Multi-Function Valve
Combines functions such as flow restriction, check, pressure reduction, and filtration, suitable for complex operating conditions.
Example: Valves requiring flow restriction, check, and pressure reduction in high-rise building water supply systems.
Application Scenarios
Water Supply System
Prevents backflow of water when the pump stops, while limiting maximum flow to protect pipelines.
Example: Secondary water supply pump rooms in residential areas, industrial cooling water circulation systems.
Fire Protection System
Stabilizes fire protection network pressure, prevents water hammer damage to equipment, and ensures unidirectional water flow.
Example: Fire sprinkler systems, fire hydrant systems.
Heating, Ventilation, and Air Conditioning (HVAC)
Regulates the flow rate of cooling water or chilled water to prevent backflow that could disrupt the system.
Examples: Central air conditioning cooling towers, fan coil systems.
Industrial Processes
Controls fluid flow and prevents cross-contamination in chemical, pharmaceutical, and other processes.
Examples: Multi-media filtration systems, reverse osmosis water treatment systems.
Advantages and Features
Space Saving: Integrates two functions, reducing the number of valves and installation costs.
Easy Maintenance: Compact structure, low failure rate, easy to maintain.
High Adaptability: Fixed or adjustable models can be selected to meet different operating conditions.
High Safety: Prevents backflow and sudden flow changes, protecting the system for stable operation.
Selection Considerations
Flow Range: Select the appropriate flow limiting capacity based on system requirements.
Pressure Rating: Ensure the valve's pressure resistance meets the system's maximum pressure.
Media Characteristics: Consider fluid temperature, corrosiveness, and impurities; select appropriate materials (e.g., cast iron, stainless steel, copper alloy, etc.).
Installation direction: The direction of fluid flow must be clearly defined for the check valve function to avoid failure due to incorrect installation.
Current-limiting Check Valve factory
