Tokyo Keiki’s EPCG2 and EPFG series are both proportional pressure valves used across industrial hydraulic systems, and the naming convention alone doesn’t make the distinction obvious. The real difference comes down to valve function, control range, and how each series integrates with a controller.
Here’s how the two compare, and what it means when you’re specifying a replacement or evaluating a unit for repair.
Valve Function
The EPCG2 series is a proportional relief valve, regulating system pressure by proportionally bleeding excess flow off to tank in response to a command signal. The EPFG series is a proportional flow control valve, regulating flow rate rather than pressure. While both use a similar proportional solenoid architecture, they serve fundamentally different roles in a circuit and are not interchangeable despite their similar construction.
Control Range and Response
Because the EPCG2 is managing pressure relief, its response characteristics are tuned for stability under pressure spikes and transient load changes. The EPFG, tuned for flow regulation, prioritizes smooth, proportional metering across a flow range rather than rapid pressure response. Confusing the two during a replacement — even when the physical valve looks similar — will produce a circuit that doesn’t behave as designed.
Controller Compatibility
Both series are typically paired with an external controller such as an EPAD or P-X/Z unit rather than fully integrated electronics. When a valve comes in for repair, verifying which controller model and settings were originally paired with it matters — using mismatched controller parameters is a common cause of a freshly repaired valve behaving inconsistently once reinstalled.
Which One Belongs in Your System
If your circuit needs proportional pressure relief or safety limiting, the EPCG2 is the correct series. If the application calls for proportional flow metering — controlling actuator speed, for example — the EPFG is the right fit. Matching a replacement to the original function, not just the physical valve size, is what keeps the circuit performing as intended.
Not sure which Tokyo Keiki series is currently installed in your system, or need one diagnosed and repaired to spec? Performance Servo can identify the exact EPCG2 or EPFG variant and rebuild it with tested, calibrated electronics.