In large-scale irrigation and hydropower projects, selecting the right large-diameter butterfly valve is crucial to ensuring the operational safety and efficiency of the entire water transmission system. Especially in long-distance, high-flow, and low-head gravity-fed pipelines, the DN3750 butterfly valve stands out for its good sealing performance, stable structure, and engineering adaptability.
The DN3750 hydraulic butterfly valve is a shut-off type valve designed for large-diameter gravity-fed pipelines. It is not intended for flow regulation. It is widely used in irrigation dams, hydropower stations, and reservoir control systems. Recommended pressure ratings are PN6 or PN10. The valve is typically equipped with electro-hydraulic actuators that allow full opening or closing within one minute.
This white paper presents a real-world irrigation dam project to illustrate the valve’s application, structural design, actuation method, and technical selection criteria.
Where is the DN3750 Butterfly Valve Used?
The DN3750 butterfly valve is typically used as a mainline shut-off valve in the following scenarios:
- Irrigation Water Transmission Systems: Used as the main valve in cross-regional gravity-fed or pumped irrigation projects, where pipe diameters exceed 3 meters and the system operates under moderate static pressure.
- Hydropower Station Intake Systems: Installed upstream of turbine units for emergency shut-off and equipment protection.
- Reservoir Diversion & Control Systems: Controls the discharge and diversion of water between reservoirs and canal networks.
Structural Design and Working Principle
The DN3750 butterfly valve comprises the following major components:
- Valve Body: Welded carbon steel structure with double flanges
- Disc: Reinforced steel plate with anti-deformation ribs
- Seal: Embedded EPDM rubber or metal-composite seal
- Shaft: High-strength stainless or alloy steel
- Actuation Unit: Electro-hydraulic actuator, Gear operated, Hydrualic actuator, Pneumatic actuator.
Note: This valve is for ON/OFF control only and not designed for throttling or flow regulation.
Actuation Method and Operation Time
- Electro-hydraulic Control
- Opening/closing time: ≤ 1 minute
- Control: Remote or automated
- Maintenance: Moderate, adjustable
Recommended configuration: Use electro-hydraulic control for both DN3750 main valves and DN1500 branch valves to ensure quick response and easy system integration.
Case Study: Irrigation Dam Pipeline Project
Project Overview:
- Pipe Diameter: 3.75 m (DN3750)
- Wall Thickness: 13 mm
- Material: A36 Carbon Steel
- Pipeline Length: 16.2 km
- Static Head: 21 m
- Static Pressure: ≈ 0.21 MPa (2.1 bar)
- Design Pressure: PN6
Valve Configuration and Layout:
- Main Pipeline Outlet: DN3750 PN6 Butterfly Valve, Quantity: 1, Electro-hydraulic
- Branch Lines: DN1500 PN6 Butterfly Valve, Quantity: 6, Electro-hydraulic
- Air/Vacuum Protection: DN250~DN400 Automatic Air & Vacuum Valves
- Flow Monitoring: Electromagnetic Flowmeters on each valve
System Highlights:
- Main valve controls entire discharge section
- Branch valves enable distributed water delivery
- Flowmeters ensure real-time monitoring
- Air valves and vacuum breakers protect against vapor lock and air hammer
THINKTANK Brand Support and Services
As a professional manufacturer with practical engineering experience in large-diameter hydraulic valves, THINKTANK offers end-to-end support for DN3750-class systems:
- Custom design based on project pressure and connection requirements
- Full 2D and 3D design documentation for integration with consultants
- Electro-hydraulic system packages including actuators and control cabinets
- On-site installation guidance and commissioning support
- Post-installation technical training and remote maintenance
Conclusion
The DN3750 butterfly valve plays a critical role in the safety and reliability of large-scale irrigation and water management systems. It is a shut-off valve designed for high-volume, low-pressure flow control. With electro-hydraulic or hydraulic actuation and reliable construction, it provides the ideal balance of performance, automation, and field adaptability.
Choose THINKTANK — for trusted, engineered valve systems that move your water infrastructure forward.
