Hydraulic valves

Single counterbalance valve in-line for open center VBZF

In stock

Overcenter valve simple effect not compensated in-line installation

The counterbalance valves (or overcenter) have the task of supporting a suspended load and controlling its downward movement. The VBZF series includes single setting valves with fixed setting flangeable on the cylinder.



The Oleoweb valves of the VBZF series are single counterbalance valves, suitable for the management and control of the movement of a hydraulic actuator in only one direction. They are valves with a flanged surface that allows installation directly on the cylinder. For connection to the distributor, there are GAS threaded ports in sizes from BSPP 3/8 "to BSPP 1/2" for recommended operating flows up to 60 lpm (15,9 gpm). The fixed setting allows to optimize the installation times and avoid possible tampering with the valve setting. The VBZF is a non-compensated valve: eventual backpressures must be added to the setting of the valve. The load management takes place on the re-entry line from the cylinder, while the delivery is possible through a one-way valve. Thanks to the pilot line with the relative reduction ratio it is possible to manage the gradual opening of the valve to control the descent of the actuator even in the presence of gravitational loads that do not generate pressure. The VBZF valve can also work as an anti-shock valve protecting the system and the structure connected to it from damage caused by pressure peaks. This is possible only if the system distributor has the spool with open center in neutral position. Oleoweb pays particular attention to the realization of the components that realize the hydraulic seal of the counterbalance valves, carefully verifying geometrical dimensions and tolerances, as well as testing the sealing of the assembled valve. The VBZF counterbalance valves are parts in body valves: all the components are housed inside a hydraulic manifold. This solution allows you to manage high flow rates while keeping down the overall dimensions. Body and external components are made of zinc-plated steel. The zinc-nickel treatment is available on request to improve corrosion resistance. Thanks to the steel body it is possible to work with operating pressures up to 350 bar (5075 PSI).