Complete Guide To Check Valves: Principles, Types, And Backflow Prevention Solutions

Check valves play an irreplaceable role in critical applications such as pump protection and water supply systems. This article will systematically introduce the technical features and valve selection points for these types of valves.

Check Valve Principle Revealed

Check valves automatically control flow through pressure differential:

● Forward Flow: The fluid pressure pushes the valve disc open.

● Reverse Flow: The valve disc automatically closes.

● No external power is required during the process, with a response time of only 0.1-0.3 seconds.

Mainstream Types Comparison

● Swing Check Valve: Suitable for large flow rates, but has a water hammer risk.

● Lift Check Valve: Good sealing performance, ideal for vertical installation.

● Dual Plate Check Valve: Fast opening and closing, with minimal water hammer effect.

● Ball Check Valve: Suitable for media containing solid particles.

Valve Selection Golden Rules

● Pump Outlet: Prioritize the use of slow-closing check valves.

● Hot Water Systems: Choose stainless steel material.

● Chemical Pipelines: Consider fluorine-lined corrosion-resistant designs.

For example, after replacing an old check valve with a new one, a certain water plant reduced the pump group failure rate by 65%, and the annual maintenance costs decreased by 280,000 yuan.