Pump-mounted low-pressure unloading valve

Oleodinamica Marchesini V0521 VEP FLP 1/2 IFF 40 pump-mounted low-pressure unloading valve

Model: V0521 · Oleodinamica Marchesini
Maximum operating pressure (bar)320
Port connection1/2" BSP
Body materialZinc-plated steel
Maximum AP port flow (l/min)20
MountingFlange mounting on low-pressure pump
ActuationHydraulic pressure

Description

Oleodinamica Marchesini V0521 (VEP FLP 1/2 IFF 40) is a pump-mounted low-pressure unloading valve for a circuit with two parallel pumps. Maximum listed flows are 20 l/min at AP, 40 l/min at BP and 60 l/min at T. The AP/high-pressure side is rated up to 320 bar, while the BP/low-pressure stage is limited to 80 bar.

When the unloading pressure setting is reached, the larger-displacement high-flow pump is routed to tank. The smaller high-pressure pump continues supplying the actuator. Port-specific flow and pressure limits must be observed independently.

Flange BP onto the larger high-flow, low-pressure pump. BP is an O-ring-sealed flange passage with a 15 mm bore. Connect AP to the smaller pump, T to tank, U to the circuit and M to an optional gauge. AP is 3/8 inch BSP; T/U are 1/2 inch BSP; M is 1/8 inch BSP.

The high-pressure branch requires a separate pressure-relief function, such as an inline relief or the main relief on the directional valve. This VEP FLP article is not specified as including that additional high-pressure relief valve. Use the exact original mounting drawing; the IFF 40 and standard bodies have different flange geometry.

The zinc-plated steel body contains hardened and ground steel internal components. Seals are standard BUNA N. The local PDF retains the complete relevant original ratings, circuit, drawings and conditions. Representative manufacturer product image for the VEP FLP series. Refer to the exact article drawing in the local PDF for its port geometry and mounting interface.

Full specifications

Technical specifications
Product type Pump-mounted low-pressure unloading valve
Maximum low-pressure stage pressure (bar) 80
Maximum operating pressure (bar) 320
Maximum AP port flow (l/min) 20
Maximum BP port flow (l/min) 40
Maximum T port flow (l/min) 60
AP port connection 3/8" BSP
BP port interface Flange with O-ring seal
M port connection 1/8" BSP
Port thread standard BSP
T port connection 1/2" BSP
U port connection 1/2" BSP
Mounting Flange mounting on low-pressure pump
Internal parts material Hardened and ground steel
Curve reference conditions Oil temperature 50 °C; oil viscosity 30 cSt
Factory type designation VEP FLP 1/2 IFF 40
High-pressure relief valve Separate valve required
Manufacturer Oleodinamica Marchesini
Manufacturer part number V0521
Product family VEP FLP
Pump arrangement Two pumps in parallel
BP port bore diameter (mm) 15
Mass (kg) 3.17
Technical specifications
Actuation Hydraulic pressure
Port connection 1/2" BSP
Body material Zinc-plated steel
Valve function Unload high-flow pump at pressure setting
Technical specifications
Seal material BUNA N