In most types of processing systems as well as in systems designed to transport media, maintaining pressure and flow is essential. It is also critical to prevent backflow through the system should there be an unexpected drop in pressure or flow rate or volume.
The use of a chemical check valve is essential for all the reasons mentioned above. It becomes critical when backflow may cause contamination of the system, increased risk of system failure or other types of issues that result in downtime.
The Role of the Check Valve
The check valve, also known as a non-return valve or a one-way valve is found in virtually all types of systems. This includes in plumbing systems, in pumps as well as in industrial processing applications.
These valves are responsive to pressure. Pressure from the inlet side of the valve keeps the valve fully open and allows the flow of the media. Should the pressure or flow volume drop, the interior ball, diaphragm, disc or other controlling element immediately seals the inlet port, stopping any backflow through the system.
Critical Considerations
The cracking pressure listed for any chemical check valve is an important factor. This is the pressure that is required to cause the valve to engage and operate. As these valves are automatic and not controlled by manual adjustments or system controllers, having the correct cracking pressure is essential to prevent any backflow.
In chemical applications, the use of a specialized chemical check valve is another critical consideration. These valves have all wetted surfaces on the interior of the valve treated with PFTE or a similar non-reactive, non-corrosive type of material. Not only does this extend the life of the valve, but it also enhances operation even when the valve is very infrequently required to operate to prevent backflow.
