Products

Product Overview

The Automatic Recirculation Check Valve is installed on the outlet pipeline of high-pressure boiler feed pumps in thermal power plants to prevent reverse flow and protect the feed water pump from damage. It works together with an automatic minimum flow recirculation bypass valve to ensure safe pump operation under low-load conditions or when the outlet shut-off valve is closed.

When the main check valve opens, the recirculation bypass valve automatically closes. When the flow rate decreases, the bypass valve reopens to maintain the pump’s minimum safe operating flow. This design effectively prevents pump overheating, cavitation, and water hammer damage, ensuring stable and reliable system performance.

The valve is not recommended for media containing solid particles or high-viscosity fluids.

Working Principle

1. When the outlet valve opens and the feed water pump starts, system pressure increases.
2. Once the pressure reaches the preset level, the valve disc lifts from the seat under fluid pressure, allowing the medium to flow through the valve.
3. As the valve disc rises, it drives the linkage mechanism to close the recirculation discharge port automatically.
4. When the flow rate decreases, the valve disc moves downward, reopening the recirculation port to maintain the pump’s minimum allowable flow.
5. When the pump stops, the valve disc automatically closes under spring force and reverse pressure, preventing backflow and protecting the system from high-pressure water hammer.

The valve operates in coordination with the recirculation bypass valve to maintain continuous system safety and operational stability.

Product Features

1. Reliable Pump Protection

Designed to work with an automatic recirculation bypass valve, ensuring safe pump operation under varying load conditions.

2. Automatic Flow Regulation

The main valve disc moves vertically:

• During normal flow, the bypass valve remains closed.
• During low-flow or reverse-flow conditions, the bypass valve automatically opens to maintain minimum pump flow.

3. Excellent Sealing Performance

The valve disc sealing surface is hard-faced with stainless steel overlay welding, providing:

• High wear resistance
• Strong anti-scuffing performance
• Long service life
• Reliable sealing capability

4. Water Hammer Prevention

Automatically prevents reverse flow and reduces the risk of pressure surges and hydraulic shock in high-pressure feed water systems.

5. Vertical Installation Design

The valve is designed for vertical installation to ensure proper operation and performance.

Applications

The Automatic Recirculation Check Valve is widely used in:

• Thermal power plants
• Boiler feed water systems
• High-pressure pump systems
• Industrial water circulation systems
• Petrochemical and energy industries

Technical Advantages

• Automatic operation without external power
• Protects pumps during low-load operation
• Reduces maintenance and downtime
• Improves system safety and efficiency
• Durable stainless steel sealing surfaces
• Stable performance under high-pressure conditions