Water hydraulic costs are washed away

A Yorkshire company claims to have developed a technology that allows water-based hydraulics to compete on cost with systems using hydraulic oils. With the help of a DTI Smart Innovation Award, the Hull-based Water Hydraulics Company (WHC) has developed and patented a range of valves offering both pressure and flow control.

Although other water-based hydraulics technologies are available, they are generally expensive and are therefore usually restricted to niche applications where immunity from the risks of fire or oil leaks is the key requirement, and price is secondary.

The WHC`s Janus control valves (shown above) offer directional flow and pressure control for system pressures up to 200 bar, not only for water, but for any corrosive, low-viscosity fluid. They operate on the principle of a hydrostatically balanced face valve that mimics the function of a spool arrangement.

Functions not commonly available from a single valve, such as 4/3 directional control, are possible. For load-holding applications, a bolt-on, pilot-operated check is available in both single- and double-acting versions. For volume applications, manifold versions containing both pressure and flow control functions can be provided.

The WHC claims that its designs can cope with contaminated fluids. The operating pressure generates sealing forces that produce sub-micron clearances, preventing contaminants from entering the bearing interfaces. Direct valve actuation is said to ensure that contaminants will not clog or destroy the designed pressure balances.

The section of the valve that controls the pressure is different to that providing the seal. The valve`s efficiency is therefore unaffected even if extremely high fluid velocities erode the specially selected materials.