Yuken’s EFBG and EBG series are both proportional electro-hydraulic relief valves, and the naming convention alone doesn’t make the distinction obvious. The real difference comes down to flow capacity, construction, and the level of energy-saving functionality each series offers.
Here’s how the two compare, and what it means when you’re specifying a replacement or evaluating a unit for repair.
Flow Capacity and Frame Size
The EBG series pairs a compact, high-performance proportional pilot relief valve with a low-noise main relief valve, making it well suited to smaller circuits where space is limited. The EFBG series is a high-flow design, rated up to 1,000 L/min depending on size, and is built for larger circuits where a single valve needs to manage substantial flow and pressure relief duty.
Energy-Saving Function
The EFBG series is specifically built as a flow control and relief valve that supplies only the minimum pressure and flow an actuator needs, reducing wasted hydraulic power compared to a fixed-displacement system running against a standard relief valve. The EBG, being a more straightforward proportional relief valve, doesn’t carry the same integrated flow-control function — it’s focused on proportional pressure regulation rather than combined energy optimization.
Amplifier Compatibility
Both series are designed to work with Yuken’s dedicated power amplifiers rather than standalone operation, and the amplifier settings are tuned to each valve’s specific coil resistance and pressure adjustment range. When either valve comes in for repair, confirming the exact model and amplifier pairing is important — the wrong amplifier profile will produce a valve that tests inconsistently even after a clean mechanical rebuild.
Which One Belongs in Your System
If your circuit is compact and primarily needs proportional relief, the EBG is generally the right fit. If your system requires higher flow capacity along with energy-saving flow control, the EFBG is the better choice. Matching a replacement to the original series, size, and amplifier pairing matters more than matching pressure rating alone.
Not sure which Yuken series is currently installed in your system, or need one diagnosed and repaired to spec? Performance Servo can identify the exact EFBG or EBG variant and rebuild it with tested, calibrated electronics.