A pressure seal check valve is a specific industrial type designed to prevent backflow in high-pressure and high-temperature applications. Pressure seal check valves are typically used in the oil and gas, petrochemical, power generation, and chemical processing industries, where they are required to operate in extreme conditions. They are designed to withstand high pressures and temperatures and provide reliable, long-lasting performance.

Pressure seal check valves allow fluid to flow in one direction while preventing backflow in the opposite direction. They are typically designed with a disc that can move freely in one direction but is prevented from moving in the opposite direction by a spring or other mechanism. When fluid flows in the forward direction, the disc opens to allow flow, but when the flow stops or reverses, the disc closes to prevent backflow.

Pressure seal check valves are available in different types, including swing, lift, and axial flow check valves. Each type has its unique features and applications. For example, swing check valves are commonly used in pipelines designed to provide low-pressure drop, while lift check valves are used in high-pressure and high-temperature applications.