6 Things You Should Know About Pneumatic FRLs

Post By: Tom Rowse On: 01-07-2019 - Automation & Control - Pneumatics

The latest trends in machine automation indicate that pneumatics is keeping up with the electrical Joneses in the Fourth Industrial Revolution. While actuators and position sensors might represent the cutting edge of pneumatics evolution, the developments in air preparation are not far behind in their sophistication. FRL units, or combined Filter-Regulator-Lubricator systems, are often now equipped with pressure sensors, flow meters and other types of sensors for measuring air pressure, flow, contaminants and everyday usage. In this way, machine performance can be closely monitored, faults identified and adjustments made before any problems arise. Performance parameters can be compared using data analytics from the device against manufacturers' specs, in order to understand what factors may be affecting performance and how they can be rectified.

It's important, not only to choose the correct device for your particular application but also to carry out regular and appropriate maintenance. Wherever possible, predictive maintenance procedures should be built into your IIoT-enabled devices, so you can make sure that the equipment is operating to spec and thus extend its service life. In order to install the best possible FRL for your device and to keep it running with the least possible maintenance, here are six key criteria to consider:

1. The Operating Environment

The initial selection of an FRL unit is most importantly influenced by its operating environment, particularly whether it is to be situated indoors or out. It’s vital that the operating components of the FRL are constructed from appropriate materials and designed to withstand their environment, and the first elements of this are extremes of temperature and climate. If the assembly is to be located outdoors, the range of possible operating temperatures must be taken into consideration, as extremes of heat or cold will require working components with specific temperature ratings. FRL assemblies used in oil rigs and other marine environments must be able to withstand saltwater corrosion, and water treatment plants be resistant to leakage and wear. Other extreme environments such as chemical or caustic operations, clean rooms, food and beverage preparation and ATEX conditions will demand different types of components, with secure seals or mountings inside a protective enclosure.

2. Proper Pressure Specification

The specifications of your FRL depend on the air-supply pressure of the device, equipment or plant. Most FRL components are constructed to operate under pressures up to 10, in standard configurations and sizes, though some equipment air supplies are rated for up to 17 bar. In these circumstances, the equipment or device should specify a high-pressure regulator and filter unit – newer FRL models can even handle pressures up to 20 bar.

3. Lubrication

Not all pneumatics require a lubricator, although it’s more common than not. Your machine will perform better with proper lubrication for its pneumatic valves and cylinders, which acts as a detergent in the air system and is built into the FRL assembly. The FRL continuously lubricates the system, with the clean oil washing out any contaminants that would otherwise cause sticking in the valves and cylinders. Non-lubricated pneumatics will usually need both coalescing and particulate filters instead, to remove the contaminants otherwise washed out by the lubricant.

4. Lockout and Shutdown Valves

With today’s modular design architecture, it is simplicity itself to add lockout valves (high-flow exhaust) and/or shut-off or isolation valves (low-flow exhaust) to an FRL assembly. The decision to install such devices is application-specific and usually dictated by the machine's components. Manually or electrically activated lockout valves come in two versions – quick-exhaust or quick-exhaust with soft-start – which, when activated ensure that no airflow reaches components downstream of the FRL. They are commonly required in a pneumatic system to vent the air from the equipment in the event of a mechanical jam or an unsafe operator incursion.

Safety is paramount, so live pneumatic systems must always be shut off or isolated before any routine or emergency maintenance is performed. Isolation or shut-off valves are installed upstream of the FRL assembly, and are used to drain the potential compressed air energy safely into the atmosphere through a back-flow exhaust. Proper tag-out/lock-out procedures must also be observed.

5. Air Flow Rate

When selecting components for your FRL unit, the air flow rate is one of the most important factors to consider, as the FRL must be properly sized according to the machine's required flow rate. This rate is determined by calculating the volume of air required to fill and exhaust the relevant pneumatic component, and the amount of time required for the unit to respond. For most equipment designers, accurately calculating the air flow requirements of a pneumatic machine is one of their most complex and laborious tasks, but doing it correctly will make your pneumatic devices more efficient and cost-effective.

Engineers also match up the port size of the FRL with the port sizes of the cylinder or valve manifold, and many manufacturers supply FRLs in a series with overlapping port sizes. Significant increases in nominal flow rates can be achieved using each larger series, but changing port size also within a series can effect minimal alterations to flow capacity which may be more convenient.

6. Filter Replacement

This is an area where preventive maintenance is strongly advised, because many users are not aware that pneumatic equipment's filter elements need to be replaced at regular intervals. Failure to do so in a timely manner can lead to inefficient performance and possible machine downtime. Preventive maintenance has become easier with modern FRLs that have electronic or warning light indicators to raise a maintenance alert, while the modular components of today's FRLs make maintenance significantly easier. Older systems can still be monitored by checking the condition of filter and lubricator bowls for accumulated water and a steady oil supply.

FRLs may be the least prominent feature of a pneumatic system, but they have a significant impact on its efficiency and productivity. Correct selection, sizing and maintenance of FRL components will save money over time, as machines function more efficiently and for longer, experiencing fewer leaks and conserving both air and energy.

Filters, Regulators and Lurbicators

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