The VPPL‑3L‑3‑G14‑0L40H‑A4‑A‑S1‑7 is a directly actuated piston‑type proportional‑pressure regulator from Festo’s VPPL series, designed for electrical, continuous adjustment of compressed‑air pressure in industrial automation and machine‑tool applications. It functions as a 3‑way valve with closed valve function, meaning it can supply pressure to port 2, exhaust to port 3, and maintain the set pressure at the outlet when the control signal is held constant. The regulator accepts an analogue 4–20 mA control signal, where the setpoint and actual‑pressure values are transmitted over the same line, enabling closed‑loop pressure control when paired with a compatible PLC or process controller. The unit is especially useful for dynamic clamping forces, tension control, pneumatic‑cylinder force regulation, and tool‑changer‑sequence‑pressure cascading in CNC and robotic workcells.
Technically, the VPPL‑3L‑3‑G14‑0L40H‑A4‑A‑S1‑7 supports an input‑pressure range of 0–50 bar (0–5 MPa) at port 1, and it regulates the output pressure at ports 2 and 3 between 0.4 bar and 40 bar (0.04–4 MPa) with a maximum pressure hysteresis of 0.04 MPa (≈0.4 bar), ensuring smooth, stable pressure control. The nominal flow rate is about 245 l/min (standard‑conditioned, DIN‑1343), sufficient for many pneumatic‑actuator applications, and the switching times are ≈428 ms on and ≈654 ms off, which is acceptable for most process‑control cycles. The valve’s electrical interface uses M12, 5‑pin, A‑coded connectors for 4–20 mA input, 4–20 mA output (actual value), and diagnostics, with reverse‑polarity protection and 100% duty cycle operation at a DC supply voltage range of 21.6–27.6 V and up to 26.7 W power consumption. If the control cable is interrupted, the safety position drops the output pressure to 0 bar, enhancing safety in lost‑signal conditions.
Mechanically, the regulator is built in an anodised wrought‑aluminium housing, with 3 mm nominal‑size internal supply and exhaust channels and G1/4 pneumatic ports (ports 1, 2, and 3) for standard compressed‑air fittings. The soft‑sealing principle (NBR‑type seals) ensures good sealing‑air‑tightness and low wear under typical industrial‑air conditions, and the unit is rated for media temperatures of 5–50 °C, ambient temperatures of 5–50 °C, and storage temperatures of –10–60 °C, suitable for factory‑floor PLC and pneumatic cabinets. The IP65‑rated protection class and through‑hole mounting make it easy to mount on panels or rails, while the 1100 g weight keeps the assembly compact but robust. The linearity error of ±1%FS, total accuracy of ±1.5%FS, and temperature coefficient of 0.04%/K ensure high‑precision pressure regulation over time and temperature swings, which is critical for repeatable clamping and tension control in CNC and packaging machines.
