Tough test

From ship-hoisting in the Gulf to contamination-free medical clean rooms, technology is keeping pace with the increasingly complex demands made of control applications. Julia Pierce reports


Whether working in construction in the deserts of the Middle East or supporting those searching for oil in the Arctic, wherever hydraulic and pneumatic applications are involved, the technologies are continually expected to deliver more.

Nowadays, such systems are used in highly testing environments, covering everything from the development of landmine clearance equipment to lifeboat launch systems — the RNLI uses systems designed and supported by BYPY Hydraulics and Transmissions of Shropshire.

In the Middle East, Rexroth recently successfully supplied the complete drive and control technology for two ship-lifting and transfer installations at purpose-built maritime centre Dubai Maritime City.

These included the use of a powerful wheel tractor with hydrostatic drive to pull ships over a rail transfer system ready to be repaired in the inland dry docks of Jadaf Dubai shipyard, providing the facility with direct access to the sea. The equipment had to be capable of hoisting cargo ships up to 430ft (130m) long and weighing up to 6,000 tonnes out of the Persian Gulf before transporting them overland.

The largest ship-lifting facility in the Gulf region, the installation was completed in just 18 months, despite difficult conditions. ‘A special design protects the technology from sand, salt water and heat,’ said Hans von Herwerden, Rexroth sales manager for ship-lifting technologies.

‘The maintenance-free motors and the electronics are designed to ensure they work reliably, even under extreme climate conditions, with daytime temperatures of up to 50º C, sandstorms and high levels of atmospheric humidity,’ he added.

‘The first lifting facilities, which have been in operation without problems since April 2007, verify this.’

To get to the dry docks, the ships sail into a dock, on the base of which there is a steel platform that serves as a pallet. Electrically-powered winches synchronously hoist the platform, together with the ship, four metres above sea level before it is taken to the inland facility. It takes just two hours between the ship mooring in the Gulf docks and its arrival in the dry docks.

At the other end of the temperature spectrum, Parker Hannifin recently released its 692 hose line, designed to operate in temperatures of -40ºC and created specifically for material handling and over-the-sheave applications.

The design and construction of the 692 hose allows for a tighter bend radius compared with other hoses on the market, claims the company, which saves space in the mast and increases visibility for forklift truck operators. To improve visibility for operators, components must be moved or reduced in size and the 692 hose addresses both concerns.

Rated to the tightest bend radius in the industry, the hose enables smaller pulleys to be used in the mast area, which makes more space available. With a smaller outside diameter than other hoses, more area is gained in the mast area, improving visibility.

Greg Reardon, Parker Hose products division business development manager, said the hose provides a continuous 206 bar rating for all sizes and a 4:1 safety factor, which enables it to work on most forklift models — even in the coldest of conditions.

Alongside this, the group has also launched its VikingXtreme Valves, a heavy-duty industrial in-line valve series specifically dedicated to extreme environments for industries such as quarrying and road transport. With an operating temperature range of -40°C to 60°C, a maximum pressure of 16 bar, four valve sizes, and four sizes of ports, the series offers extended life in the toughest applications.

The components also have numerous applications in the sports and leisure industry. Burkert Fluid Control System’s technology was used in energy generation in Turin during the 2006 Winter Olympics, where mass flow controllers were introduced in the biathlon as energy supply systems. At the same games, Burkert water flow transmitters were used in snow guns to allow the scheduled events to proceed even if snowfall was poor.

But extreme environments are not solely defined by climate demands. In the medical sector, clean rooms mean every component must avoid creating contamination while also dealing with harsh chemicals and the need to survive regular cleaning. ‘Pushing the limits of this technology in any demanding environment — from extremes of temperature, to the extremes of medical cleanliness — requires very careful material selection, extensive experience and testing, and rigorous attention to design details,’ said Burkert’s Graham Oliver.

‘In the world of hygienic processing for medical applications, for example, compactness, smart communication, very high-precision dosing and smaller device footprints are the driving factors. In producing valves for use in water purification for medical intravenous (IV) drips, coping with high temperature wash-downs and minimising product contact with the medium is essential.’

Oliver said high grades of stainless steel and sometimes exotic compounds for seals are required to tackle tough issues such as dead legs, areas where water stagnates in a piping system, causing cross-contamination.

He said Burkert’s Robolux valve has been used by a medical materials company in a water purification process to achieve independent process switching functions with one diaphragm. Originally designed and extensively developed for chromatography system applications, the technology makes it possible to replace two traditional shut-off diaphragm valves and at the same time eliminate all dead legs and one tee-piece with one single valve.

Development engineers at Burkert have over the years gathered expertise in a wide range of intensive care applications, from respirator technology and anaesthesia to insufflators for keyhole surgery. This has allowed them to develop solutions in a range of applications from gas mixing and distribution, to systems for cleaning and leak testing endoscopes.

As equipment has become more complicated to deal with increasingly complex demands, its applications mean it must also be highly robust in the face of extreme conditions.

Despite the challenges, engineers are continuing to innovate and overcome these problems — to the benefit of both the industrial and the leisure sectors.