The 2FRE6B-2X is a 2-way proportional flow control valve in NG6 (CETOP D3) format that regulates flow independently of pressure and temperature fluctuations. A proportional solenoid with inductive position transducer (LVDT) drives the metering orifice in closed loop — the spool position is continuously measured and corrected, delivering repeatable flow accuracy even as fluid viscosity and load pressure shift during operation.

What makes closed-loop LVDT control different from standard proportional valves?

Standard proportional valves operate open-loop: the solenoid receives a command signal, but there is no feedback on whether the spool actually reached the target position. The 2FRE6B-2X uses an LVDT to measure spool displacement and feeds it back to the amplifier, which corrects any deviation in real time. This eliminates hysteresis and drift — flow stays on target regardless of coil temperature or friction. On power loss or LVDT cable break, the metering orifice closes automatically.

What flow ranges are available?

The 2FRE 6B-2X is offered in five flow variants: 3, 6, 10, 16, and 25 L/min maximum. The ordering code suffix identifies the range — for example, /3QK4MV delivers 3 L/min, /25QK4MV delivers 25 L/min. The valve pairs with an external amplifier (VT-VRPA1-150-1X or VT-MRPA1-150-1X) that provides two adjustable ramps for smooth start-up and controlled shut-down.

How is it installed?

The valve mounts on a standard NG6 subplate with port pattern ISO 4401-03-02-0-05. FKM seals are compatible with mineral oils (HL, HLP, HLPD, HVLP) and environmentally acceptable hydraulic fluids (HETG, HEES, HEPG, HFDU, HFDR). For bi-directional flow control, a Z4S 6 rectifier sandwich plate stacks between the valve and subplate.

Flow Range Variants

Frequently Asked Questions

What is the difference between RV and MV variants?

RV variants (e.g. /8LK4RV) include a check valve for free return flow from port B to A and have no external closing port. MV variants (e.g. /10QK4MV) omit the check valve but add an external closing port P for start-up jump suppression — important when the actuator must not move unexpectedly at system power-up.

Which amplifier does this valve require?

The 2FRE 6B-2X requires an external amplifier. The analog VT-VRPA1-150-1X or digital VT-MRPA1-150-1X are the standard pairings. Both provide ramp generators for smooth opening and closing, and the command value range is 0–100% corresponding to 0–max flow.