Q:When should check valves be used?

When two or more pumps or blowers are installed in parallel, check valves are used to isolate the ones that are not operating. In some applications, backflow is detrimental to the process or to equipment and must be prevented.

When should dual plate wafer type check valves check valves be used?
Dual plate wafer check valves are versatile and can be used in a variety of scenarios. However, there are specific situations and conditions where their design and features make them particularly advantageous:

1. Space Constraints: One of the main advantages of dual plate wafer check valves is their compact design. Dual plate wafer check valves are ideal for installations where space is limited, such as in tight piping systems, on board ships or in compact machinery.
2. Quick Closure Required: The double plates in these valves are spring-loaded, allowing them to close quickly. This quick response is beneficial in systems where rapid backflow prevention is critical.
3. Low Pressure Drop: Systems that require minimal flow resistance can benefit from double plate wafer check valves. The design of double plate wafer check valves typically results in a lower pressure drop compared to other types of check valves.
4. Horizontal and Vertical Installations: Dual plate wafer type check valves can be installed in both horizontal and vertical pipelines. However, in vertical installations it's important to ensure that the plates swing in the direction of gravity.
5. Protection of Equipment: In systems where reverse flow could damage sensitive equipment such as pumps or compressors, double door wafer type check valves can be used to prevent reverse flow.
6. Wide range of applications: Double door wafer type check valves are suitable for a wide range of applications including water and wastewater treatment, petrochemical plants, power generation, HVAC systems and more.
7. Variety of Fluids: Double door wafer type check valves can handle a wide range of fluids, from water to oil, gas and some corrosive substances, provided they are made of suitable materials.
8. Reduced Water Hammer: The quick closure and lightweight design of the Dual Plates check valves can help reduce the potential for water hammer, a sudden surge of pressure when a moving fluid is forced to stop or change direction.
9. Cost effective for large diameter pipelines: For large diameter pipelines,duo plate wafer check valves can be more cost effective than swing check valves due to their lightweight and compact design.

When they may not be ideal:
1. Thick Fluids or Slurries: In situations where the fluid is very thick or contains high levels of suspended solids, the plates may not close properly resulting in potential leakage.
2. Extreme Temperatures: While they can handle a range of temperatures, it's important to ensure that the valve's materials and seals are suitable for very high or very low temperatures.
3. Highly Corrosive Fluids: If the fluid is highly corrosive, it's essential to select a valve made of materials resistant to the specific corrosive agent.

Applications:
1. Petrochemical and Refineries: Dual plate wafer type check valves are commonly used in oil and gas pipelines to prevent reverse flow of fluids.
2. Water and Wastewater Treatment: Used in treatment plants to ensure that treated water or wastewater doesn't flow back into the system.
3. Power Generation: In power plants, especially in cooling systems and boiler feed lines, dual plate wafer type check valves ensure that water and other fluids flow in the correct direction.
4. Marine and Offshore: Dual plate wafer type check valve withe full rubber the body with full rubber design makes them ideal for marine applications and the compact design makes them ideal for marine applications where space is at a premium, such as ballast systems.
5. HVAC Systems: n heating, ventilation and air conditioning systems, these valves can prevent the reverse flow of coolant or water.
6. Fire Protection Systems: In sprinkler systems and other fire protection systems, dual plate wafer type check valves ensure that water flows in the right direction when needed.
7. Agriculture: In irrigation systems, dual plate wafer type check valves can be used to ensure that water flows in the desired direction.
8. Industrial Processes: Dual plate wafer type check valves are used in various industrial processes where it's vital to prevent backflow of liquids or gases.

In summary, double plate wafer check valves should be used when a compact, efficient and responsive check valve is required. However, always consider the specific requirements of the application and the characteristics of the fluid being handled when selecting a valve.