Oleodinamica Marchesini V0303 VBCD 3/8 SE FL PB single counterbalance valve

Oleodinamica Marchesini V0303 is the VBCD 3/8 SE FL PB single counterbalance valve, with maximum flow of 50 l/min and the factory pilot-ratio designation 1:4.25. The current manufacturer sheet lists a 350 bar maximum pressure, while the supplier table lists 330 bar for the same code; these source-specific values must be confirmed for the applicable execution.

The counterbalance element holds an overrunning actuator and meters its return flow when pilot pressure is applied. Only the specified actuator line is controlled; the other line provides the separate free-flow and pilot path shown in the original circuit.

Connect V1/V2 to the supply and flange C2 to the actuator side requiring load control; C1 serves the free-flow side. The factory states that V1/V2 are reversible. The supply ports are 3/8" BSP, the gauge port M is 1/4" BSP and the C1/C2 flange bores are 9 mm. A flange bore diameter is not a pipe-thread designation.

The current factory sheet gives pilot ratio 1:4.25, body length L of 108 mm, catalogue dimension L1 of 171.2 mm and mass 1.400 kg. The supplier rounds the ratio to 1:4.3 and lists 330 bar and L1 of 175 mm. The factory sheet is retained locally for comparison; no single unqualified maximum-pressure filter is assigned while that execution-rating discrepancy remains unresolved.

The catalogue standard setting is 320 bar, separate from the component maximum pressure and from the actual setting of a delivered unit. The manufacturer specifies a setting at least 1.3 times the load-induced pressure to allow the valve to close under maximum load. Apply that guidance to the machine circuit rather than treating it as a new order-code combination.

The zinc-plated steel body contains hardened and ground steel parts with standard BUNA-N seals. The local PDF retains the complete relevant original manufacturer spread, including the exact article table, hydraulic symbol and installation drawing. Where curves specify oil at 50 °C and 30 cSt, these are reference conditions rather than operating-temperature limits.