Fluid Power – Future technology! Know more about Walvoil’s presentations at the last IFK Congress

As one of the world’s most significant scientific conferences on fluid power control technology and systems, IFK offers a common platform for the presentation and discussion of trends and innovations to manufacturers, users, and scientists.
With the motto ‘Fluid Power – Future Technology!’ the 12th IFK has proved that fluid power adapts to technological challenges and provides cutting-edge drive solutions.

If you are interested to know more about Walvoil’s presentations at the 12th International Fluid Power Congress (October 12-14, 2020), here following a short resume of the abstracts presented online.


Pietro Marani *, Massimo Martelli *, Silvia Gessi *, Cesare Dolcin **
CNR-IMAMOTER, Via Canal Bianco, 28, 44124, Italy*
WALVOIL SpA, Via Adige, 13/D, 42124, Reggio Emilia, Italy**

Pietro Marani
Symposium - Materials Session A-3
Monday, October 12, 10am

Even though the orifice is the simplest and most common control component in fluid power systems and cavitation is an already well-established topic in the scientific literature, the flow choking or saturation effect is largely overlooked in the common engineering practice.
Most of the times the phenomenon is completely ignored, unless the peculiar hissing noise is observed at the test rig, giving a hint that something wrong is happening in the hydraulic system. Even then, the focus is just on the possible component damage induced by strong cavitation, while the functional implications – in terms of flow characteristic – are neglected.

The objective of the paper is to study the phenomenon of flow saturation in hydraulic orifices to assess the formulation of the different critical cavitation numbers and cavitation indexes available from literature. For this reason, a full factorial design of experiments (DOE) is performed to determine the influence of three factors: orifice size, fluid temperature and upstream pressure.

The testing is carried out on 5 orifice sizes at 3 different temperatures and 5 different upstream pressure levels. In each test, the downstream pressure is changed from 0 to the upstream pressure level, to sweep the available Δp range, both ascending and descending. In the results section an analysis of the experimental results is drawn, proposing a correlation between the critical cavitation index and the factors considered in the DOE.
To the authors’ knowledge, no systematic analysis, as the one here proposed, currently exists in literature for mineral oil applications.



Davide Mesturini*, Cesare Dolcin*, Ulderico Busani*, Pietro Marani**, Antonella Bonavolontà***, Emma Frosina***
Walvoil SpA, via Adige 13/D, 42124 Reggio Emilia, Italy*
C.N.R.-IMAMOTER, Via Canalbianco 28, 44124 Cassana (FE), Italy**
UniNA FPRG, Università degli Studi di Napoli "Federico II", via Claudio 21, 80125 Napoli***

Davide Mesturini
Components Session 5-2
Tuesday . October 13 . 2:15pm

Various academic studies show that in the use of common ICE Off-road Vehicles only about 10-15% of the available power at fuel level is actually transformed into useful energy for the actuators.
Particularly the Directional Control Valves are responsible for the dissipation of about 35-40% of the hydraulic energy available at the pump level.
The machine electrification trend makes it even more urgent to optimize the hydraulic system to ensure greater performance and higher battery autonomy.

Traditional Directional Control Valves design solutions neglect important opportunities for reducing losses and improve internal regeneration. Especially, energy recovery is rarely applied and in any case by means of important superstructures which considerably increase the costs of the system.

This paper presents an innovative Directional Control Valve layout, based on the Downstream Compensation approach, that, in a simple and cost-effective design, allows to recover a considerable amount of energy from both the inertial loads and the simultaneous use of multiple actuators at different pressure level.
The proposed layout performance and efficiency are studied through lumped element simulation and laboratory experimental tests.