Pneumatic components reduce plant costs

Growing demand for greater functionality and capability means that the latest pneumatic components are becoming increasingly complex. With this notion in mind, plant engineers seeking cost-effective solutions need to know the optimum products available, states motion and control technology leader Parker Hannifin.

Not all pneumatic components are made equal, therefore making wise selections when it comes to pneumatic components can pay huge dividends. For instance, the ability to rectify problems prior to them becoming major plant issues has the potential to save thousands in unscheduled downtime and in maintenance and repair costs.

An effective pneumatic system must be correctly sized, installed and maintained; an ethos that extends from the compressor to the machine or workstation. However, a few ill-informed decisions could result in anything from wasted energy to complete system failure, and all the associated costs these incur.

To help avoid such expensive mistakes, a variety of different pathways can be considered when looking to optimise the performance of pneumatic components.

As with any machine, vehicle or system, regular and correct maintenance will extend its working life, and pneumatic equipment is no exception. Lubricators must not be left to run dry, while filters need cleaning, and contaminants – such as water, unwanted oils, metal shavings and corrosion – must be removed.

An indicator for preventive maintenance would be discolouration of the filter elements which would suggest that compressor oils are causing an issue. A further indicator is a distinct, audible hiss which could mean there is a system leak. Leaks typically occur where products mate or connect to the pneumatic tubing or other joining products.

Predictive maintenance avoids the cost of both reactive and scheduled preventive maintenance by only deploying maintenance routines when needed, namely shortly before a pneumatic component is predicted to fail. The route to predictive maintenance is through sensors.

For example, a flow sensor that sits in line with a filter, regulator and lubricator unit can indicate a blocked filter that might otherwise go unspotted. If a blocked filter is allowed to continue serving a pneumatic system, several problems can occur. Air supply can become restricted, contamination levels can rise, and extra heat can be generated that might compromise a system and ultimately lead to its complete failure.

The cost implications of such an outcome are significant. Today, sensors have been developed for use on almost all pneumatic components, for example, continuous position sensors on cylinders. This type of sensor can indicate whether heat or wear is being generated to the point of becoming a problem.

Modern pneumatic components can help plants save money through reduced energy consumption. Many plant engineers fall into the trap of oversizing, thinking they are playing it safe. However, a correctly sized pneumatic component is perfectly safe and avoids the extra costs associated with larger pneumatics and wasted energy.

A key tip is to use pneumatic zoning on a manifold to mix pressures, add vacuum to the application, or manage the use of supply pressure. Pneumatic zoning enables the user to section the manifold through a gasket, thus creating different pressure zones or changing the flow, or even making one zone a vacuum.

A further alternative to oversizing is to use pressure boosters, which amplify the pressure or serve as a simple reservoir to store compressed air in the system for later use.

There is a cost associated with ensuring machine and system safety, however, workplace injuries will almost certainly cost more. A simple risk assessment can add significant value to a pneumatics project.

Any potential hazards identified can be designed out or protected against using solutions such as light curtains, interlocks, machine guards or safety exhaust products. When incorporated into an air preparation system, a safety exhaust valve lets users safely and reliably shut off the pneumatic energy, stopping the flow of compressed air to the machine and enabling downstream pressure to exhaust.

There are, however, a number of criteria associated with the optimum specification of a safety exhaust valve, including fast exhaust time to faulted condition, fast switching time, using series-parallel flow so that both valve elements shift to supply air downstream and high life expectancy in switching cycles.

Low cost, Ethernet-based shop floor connectivity is the future for manufacturing industries, and many are shifting in this direction.

In stark contrast, numerous plants still rely on hard-wired solutions. However, the shift from long runs of wire trunking to a simple Ethernet port is not as daunting as it sounds, particularly with the advent of IO-Link. This is fast becoming the next significant industrial network protocol as it can provide the perfect local extension to a superior industrial Ethernet network.

It is the first input/output technology for communication with sensors and actuators to be adopted as an international standard, meaning that devices can be integrated in the same way in all commonly used fieldbus and automation systems, right up to enterprise resource planning level.

The opportunity to save money with IO-Link is substantial as users can run field level devices back to the IO-Link master, which saves in time, wiring, component costs and troubleshooting. Moreover, today’s advanced network nodes come with many advantages, such as prognostic data for predictive maintenance, as well as built-in sensors for shorts, over-current, thermal management and cycle counting.