Pneumatics technology is used widely in the commercial vehicle sector, for applications such as ventilation controls, door actuators, clutches, brakes and a range of auxiliary equipment; in each case, the systems are required to function reliably and for extended periods without maintenance. With commercial vehicles increasingly being used in countries where extreme weather conditions are typical, including wide temperature fluctuations.
Parker Hannifin has developed a new generation of valves and air preparation units that are able to operate effectively under these extreme conditions. An example of this latest technology is the new breed of heavy-duty, compact pneumatic valves, called VikingXtreme.
Unlike traditional valves, which typically use O-ring or lip seals between the valve spool and body, these ruggedly constructed units feature a single piece aluminium spool, over-moulded with a specially formulated rubber compound. This eliminates the problems of seals deforming or extruding, especially under conditions of high pressure or flow, reduces the number of component parts and provides an extended operating life. These valves are able to withstand pressures of up to 16bar and meet various salt spray and vibration tests demanded by the sector. Versions are available with a choice of solenoid coil voltage options making them suitable for use in both European and North American markets.
In addition to the valves, Parker can also offer a range of air preparation units (FRLs) suitable for used in commercial vehicle applications where conditions of shock are likely to apply. And like the latest valves, these FRL units have also been validated for transport applications, enabling manufacturers to achieve validation for complete systems quickly and simply.
Modular and compact, the FRLs will operate reliably at temperatures of up to 80ºC, and feature simple connections that allow each module to be slid easily into place and then locked securely in position using an integral clamp or over-strap. This method of assembly enables a complete FRL combination to be constructed in less than half the time taken for conventional devices. The FRLs can be assembled without the need for tools or special training, and no additional parts such as pipe connectors are required, allowing individual modules to be removed or changed quickly and easily.
Of particular benefit to commercial vehicle users is the method of filter element replacement, which is quick and simple. Simplifying the process of filter replacement encourages maintenance technicians to make regular changes and thus ensure the integrity of downstream pneumatic systems.
The filters in these latest systems can be supplied with standard 5 micron elements, with coalescing units to remove oil and water aerosols, or activated carbon elements to eliminate hydrocarbons. For low-temperature applications, the effective removal of water is essential to prevent system degradation, and in the worst case, failure. When you consider how much it costs to get a maintenance technician to cover an unscheduled breakdown at some remote location, a little extra investment in effective filtration appears more than worthwhile!
John Hill is marketing services manger, Parker Hannifin Pneumatics Division