Lee Pilot-Operated Cheks are pressure piloted to open check valves available in diameters from 0.250 to 0.500 of an inch. When pressure is applied to the pilot port, flow is allowed in the normally blocked direction. While our base version is a poppet-style valve designed for 3000 psi systems, our high-pressure models are designed for system pressures of up to 5000 psi and are available in forward and reverse flow configurations. Custom configurations with zero leak seals are available upon request.