Pilot-To-Open Check Valves

https://www.inno-valve.com/products/pilot-to-open-check-valves/

Pilot-to-open check valves are china hydraulic valve or pneumatic valves designed to control the flow of fluid in a system. Unlike traditional check valves that rely on the force of the fluid to open and close, pilot-to-open check valves use an external pilot pressure to control the valve's operation.