Duck bill check valves are a form of surge relief valve that can be used in a number of applications. These valves work by using a flexible rubber diaphragm to create a normally closed valve. As pressure is applied, the valve opens to become a circular pipe and then closes again when the flow has stopped. The valve is constructed of rubber or silicone.
There are three different types of duckbill check valves. The first is an inline model, which is fitted inside the pipe. It is usually secured with clamps. The second is the slip-on model, which is attached to the pipe flange. The third is the clamp-type, which is suitable for steel and cement pipes.
The type of material that is used to build a duckbill check valve can have a large effect on the performance and quality of the valve. Typically, these valves are made of an elastomeric material, which is often food grade silicone, liquid silicone rubber or synthetic rubber. The hardness of the material can also impact the durability and rebound resilience of the valve. It is important to select the right kind of valve for your application.
Duckbill check valves are designed to be resistant to organic contaminants. The elastomer is also fire retardant. This design ensures that these valves can withstand high pressures, as well as preventing the flow of suspended solids. This type of valve is also designed to operate at low pressure differentials. These valves can handle pressures of up to 15 meters.
Another factor that can damage a duckbill check valve is the backflow. It is important to prevent reverse flow. This can be achieved by installing the valve correctly. A proper installation ensures that the valve does not get damaged by water hammer. The clamps need to be properly positioned and secured, so that they are able to provide a tight fit on the pipe.
Aside from this, it is important to protect the rubber duck bill check valve from extreme temperatures. In some cases, a temperature of up to 300 degrees Fahrenheit can cause damage. It is also recommended that these valves are kept away from heat sources.
Duckbill check valves have a slit or flap that depicts the duck bill check valve opening of the valve and the closing of the valve. When a positive pressure is applied, the valve opens and when the flow is stopped, it closes. Depending on the type of valve, there are two options for flaps: one-way or bi-directional. The one-way version will open and close based on the pressure in the liquid, whereas the bi-directional will close and open based on the pressure in the water.
These valves can be made from a variety of materials, depending on the specific application. For example, the new series 750 duck bill check valves are made of rubber. These are available from Emerson Process Management and Daniel Measurement and Control Inc. These valves are perfect for seawater, raw water, and sewage.