Pilot-operated valves have a control circuit inside the main hydraulic circuit. Its supply and drain paths deserve the same attention as the main P, T, A and B connections.
Map the pilot supply
An internal pilot commonly draws pressure from a main port, while an external arrangement uses a separate pilot connection. Confirm the manufacturer's symbol and configuration plugs. Ask whether the required pilot pressure remains available when the main circuit unloads or reverses.
Map the pilot drain
An internal drain may share the main return path. External drainage can separate pilot exhaust from that path, but still requires a correctly routed line and an acceptable pressure level. Return backpressure can change switching behavior or exceed a pilot component's limit.
Check the whole operating cycle
Review start-up, low-load movement, maximum flow, braking and shutdown. A circuit that shifts normally on a test bench may fail when its return pressure rises in the machine. Specify supply and drain configurations in the order code and verify them against the delivered schematic.
Practical checklist
- Mark pilot supply and drain on the hydraulic drawing.
- Record minimum supply and maximum drain pressure.
- Confirm configuration plugs and external connections before installation.
Discuss your application
Explore related hydraulic products, or send JIUDING your model code and application details. Include the circuit drawing and the operating conditions relevant to the checks above so the required configuration can be reviewed.
Cover image: AI-generated editorial illustration, not a model-specific product drawing or a photograph of a JIUDING facility.
