The VCDM Series Digital Control Valve, manufactured by Metroval, is a solution developed for flow control in liquid loading and unloading systems. When associated with a Preset, it has multi-stage control and ensures stable operation from the beginning to the final cut-off of the operation, ensuring greater accuracy in the volume transferred.
Its operation is based on a self-operated system, which uses the line fluid itself as a means of action. A balanced piston, controlled by external solenoid valves, regulates the inlet and outlet of this control fluid, creating pressure differences that allow the valve to be opened and closed progressively. This principle eliminates the need for compressed air or external electric actuators, providing simpler, faster and more reliable operation.
The VCDM valve uses the line’s own pressure to move its internal piston. When the pressures on both sides of the piston are equalized, an internal spring keeps the valve in the closed position. Control is performed by two solenoid valves (one Normally Open and one Normally Closed) located in an external circuit. By modulating the frequency or amplitude of the pulses sent by the Preset, dynamic and stable flow control is achieved.
The Metroval line of digital valves is composed of two series developed for different applications in liquid loading and transfer systems: the VCDM Series, aimed at precise batch flow control, and the VSDM Series, intended for quick blocking operations and process safety.
VCDM Series – Multi-Stage Flow Control
The VCDM (Metroval Digital Control Valve) is a self-operated valve designed for dynamic flow control in loading and unloading systems. Its operation uses the line’s own fluid as a means of action, combined with a balanced piston and external solenoid valves, allowing multi-stage control throughout the operation.
This architecture enables smooth starts, nominal flow control, and progressive deceleration before final closure, ensuring high batch accuracy, reduced water hammer, and protection of flow meters and piping.
VSDM Series – Shut-Off Valve
The VSDM (Metroval Digital Shut-Off Valve) is a single-acting valve designed for on/off operation in charging applications. Installed close to the loading arm, it acts as a safety element of the system, remaining open during normal operation and performing rapid closing in emergency situations, such as overfill detection.
Unlike the VCDM, the VSDM uses only a solenoid and does not perform flow control in stages, being dedicated exclusively to the function of quick opening and closing, ensuring operational protection and safety of the loading process.
Key applications where VCDM is indispensable include:
