Throughout any type of production operation, including in the oil and gas industry, check valves are used in a variety of locations throughout a system. The choice of oil check valves in the oil and gas industry in Texas is no different, with these valves often given limited consideration despite the essential function they serve.
The Role of the Check Valve
All check valves are designed to prevent backflow through a system. They are also called no-return or one-way valves, which are both descriptive names for this specific valve type. They are fully automatic, which means they do not need any operator control to fulfill their function in the system. In fact, check valves do not have any external lever or control mechanism if they are used only for backflow prevention.
In the oil and gas industry, most of these valves are made of brass or ductile iron, but they can also be inline valves made of stainless steel if they are used in smaller types of applications, including in pneumatic systems in equipment.
Oil check valves operate by a pressure differential between the inlet and the outlet side of the valve. They have to be installed in the correct position, and the direction of flow through the valve is clearly marked on the exterior. When the inlet pressure exceeds the outlet pressure, the valve is open, with the valve closing if the inlet pressure drops below that of the outlet.
Specifics of the Valves
Due to the heavy, viscous nature of oil, the oil check valves most often used in Texas are swing valves. These valves have a disc inside that swings open or closed based on the flow of the media through the valve. Should the inlet pressure drop, the immediate backflow catches the disc and pushes it closed, immediately sealing the valve. Once the pressure on the inlet side reaches the set pressure for the valve to open, the disc swings open and the flow resumes.