By Tarren Bolton
Maintenance management is a key element of enterprise asset management and applies to the whole lifetime of your physical assets. The purpose of maintenance is not merely to ‘fix things’ but is the appropriate management of asset health for its lifetime.
The philosophy that ‘prevention is better than cure’ is very appropriate and is a crucial part of maintenance. For operating plants where this approach is formally accepted and acted upon, there is a very significant lift in the reliability of the plant.
Maintenance on plant and equipment is carried out to prevent problems arising, to fix faults and ensure that equipment is working effectively. Maintenance may be part of a planned programme or may have to be carried out at short notice after a breakdown. It always involves non-routine activities and can expose those involved (and others) to a range of risks.
Why is maintenance important?
An effective maintenance programme makes plant and equipment more reliable. Fewer breakdowns mean less dangerous contact with machinery as well as cost benefits of better productivity and efficiency.
Additional hazards can occur when machinery becomes unreliable and develops faults but maintenance allows these faults to be diagnosed early to manage any risk. However, maintenance needs to be correctly planned and carried out. Unsafe maintenance can cause many fatalities and serious injuries either during the maintenance or to the workers who use the badly (or wrongly) maintained equipment.
The Provision and Use of Work Equipment Regulations 1998 (PUWER) requires work equipment and plant to be maintained so it remains safe and the maintenance operation is carried out safely.
If you are an employer and you provide equipment for use, from hand tools and ladders to electrical power tools and larger plant, you need to demonstrate that you have arrangements in place to ensure they are maintained in a safe condition.
Think about what hazards can occur:
- if tools break during use
- if machinery starts up unexpectedly
- if there is contact with materials that are normally enclosed within the machine, caused by leaks / breakage / ejection
Failing to correctly plan and communicate clear instructions and information before starting maintenance can lead to confusion and may cause accidents. This can be a particular problem if maintenance is during normal production work or where there are contractors who are unfamiliar with the site.
Extra care is required if maintenance involves working at height or when doing work that requires access to unusual parts of the building, or when entering vessels or confined spaces where there may be toxic materials or a lack of air.
Establishing a planned maintenance programme may be a useful step towards reducing risk, as well as having a reporting procedure for workers who may notice problems while working on machinery.
Some items of plant and equipment may have safety-critical features where deterioration may cause risk. You must have arrangements in place to ensure that necessary inspections take place.
Before maintenance starts
Before you start maintenance, decide if the work should be done by specialist contractors; do not take on work for which you are not prepared or competent. Plan the work carefully before you start, ideally using the manufacturer’s maintenance instructions and produce a safe system of work. This will avoid unforeseen delays and reduce the risks. Make sure maintenance staff are competent and have appropriate clothing and equipment and try to use downtime for maintenance. You can avoid the difficulties in coordinating maintenance and production work if maintenance work is performed before start-up or during shutdown periods.
There also needs to be a focus on safe working areas – you must provide safe access and a safe place of work. Don’t just focus on the safety of maintenance workers rather take the necessary precautions to ensure the safety of others who may be affected by their work, for example, other employees or contractors working nearby. Set up signs and barriers and position people at key points if they are needed to keep other people away from the work site.
Safe plant and equipment
Plant and equipment must be made safe before maintenance starts.
Your pre-maintenance checklist
- Ensure moving plant has stopped and isolate electrical and other power supplies. Most maintenance should be carried out with the power off. If the work is near uninsulated, overhead electrical conductors, for example, close to overhead travelling cranes, cut off the power first.
- Lock off machines if there is a chance the power may be accidentally switched back on.
- Isolate plant and pipelines containing pressured fluid, gas, steam or hazardous material. Lock off isolating valves.
Other factors to consider
- Release any stored energy, such as compressed air or hydraulic pressure that may cause the machine to move or cycle.
- Support parts of plant that may fall, such as supporting the blades of down-stroking bale cutters and guillotines with blocks.
- Allow components that operate at high temperatures time to cool.
- Place mobile plant in neutral gear, apply the brake and chock the wheels.
- Safely clean out vessels containing flammable solids, liquids, gases or dusts and check them before hot work is carried out to prevent explosions. You may need specialist help and advice to do this safely.
- Avoid entering tanks and vessels where possible. This can be very high-risk work. If required, get specialist help to ensure adequate precautions are taken.
- Clean and check vessels containing toxic materials before work starts.
The dos and don’ts of plant and equipment maintenance
- Ensure maintenance is carried out by a competent person (someone who has the necessary skills, knowledge and experience to carry out the work safely).
- Maintain plant and equipment regularly – use the manufacturer’s maintenance instructions as a guide, particularly if there are safety-critical features.
- Have a procedure that allows workers to report damaged or faulty equipment.
- Provide the proper tools for the maintenance worker.
- Schedule maintenance to minimise the risk to other workers and the maintenance worker wherever possible.
- Make sure maintenance is done safely, that machines and moving parts are isolated or locked and that flammable / explosive / toxic materials are dealt with properly.
- Ignore maintenance.
- Ignore reports of damaged or unsafe equipment.
- Use faulty or damaged equipment.
CASE STUDY: Drone used in emergency tube-leak inspection
When a major coal-fired power station in Limpopo experienced a tube leak in a boiler, Skyriders Access Specialists was called upon to deploy its Elios SkyEye drone technology to conduct an emergency inspection.
This is the second time that the confined-space inspection technology has been deployed in such an application, says Skyriders marketing manager, Mike Zinn. “The client required an urgent visual inspection, in addition to determining the possible collateral damage associated with the areas,” reports Zinn.
Zinn explains that the drone was controlled from just outside of the boiler itself. “We were not necessarily flying it blind due to the presence of its cameras, but it did have to cover a considerable distance.” While there are definite challenges associated with a drone having to cover considerable distances, due to interference from other installations and signal-emitting machinery like cell phone towers for example, Zinn says that the Elios SkyEye is used indoors, where the signal is strong enough to prevent such interference. “Basically, within an enclosed structure we can travel about 150m into tunnels,” he says. “Where necessary, we can place a range extender at one end of a tunnel in a confined space, fly the drone in from the other end, and then we have signal throughout.
“When it comes to distance and range, there are definitely challenges,” he continues, “But with technology, we are able to overcome them. What we have done in the past, where we were dealing with quite a large confined space, and where the signal was erratic due to the composition of the structure, we would fly into a section, ensure it is safe, after which the operator could move into the section that has been declared safe. We would then fly the drone into the next section, declare it safe, and leapfrog on from there to deal with any range challenges presented.”
While the Elios SkyEye drone was used for inspection work on two previous occasions at the same power station, this was the first time it was called upon in an emergency situation. Skyriders dispatched a two-person team that was quickly on-site, and able to get the drone into the boiler as soon as possible.
The project shows how quickly and easily the drone can be deployed and how flexible it is. Traditionally, scaffolding or other time-consuming means of access would need to have been erected prior to inspections being conducted.
The best ‘eye’ for the job
Imported from Flyability of Switzerland, the hi-tech Elios SkyEye drone includes a full HD camera, a thermal camera and an onboard LED lighting system with remotely-adjustable intensity. Hence an array of onboard tools is available for any lighting conditions.
Zinn elaborates on the thermal camera functionality, “A thermal camera can detect something that the human eye is unable to see, such as an area of increased or decreased heat or temperature that is in contrast to the surroundings. Examples include server rooms, cable trays where there is lots of cabling, or boilers where there are small leaks. A thermal camera can pick up a heat signature that differs from the surrounding areas, which would often be an indication of where any potential problems are. For instance, it has been used on high-voltage power lines where there are slight arcing issues. The thermal camera picked up that hot spot immediately; it shows up incredibly bright and orange, compared to its surroundings, as a source of immediate identification.”
“In terms of civils works such as large concrete structures, these thermal cameras can pick up different areas of heat that can indicate potential areas of spalling. Like where there is an air pocket behind the concrete due to spalling, that area is cooler than the immediate surroundings. We can then investigate further by means of rope access,” says Zinn.
Navigating inaccessible spaces
The drone can be brought into usually inaccessible places up to many hundred metres beyond the line of sight, due to the fact that it is equipped with a wireless communications system with live video feedback.
Zinn explains that the Elios SkyEye drone is equipped with cutting-edge wireless communication that provides live feedback from the drone back to the pilot, often over distances of 150m. “That live feed sends a very clear and detailed picture back to the pilot. So, he can ‘see’ where he is flying; and where problems have been identified, he can take photographs. The fact that the feedback is live allows for a client standing there with us to observe exactly what the pilot and the drone are seeing and advise accordingly. The wireless communication feature is therefore a critical component,” emphasises Zinn.
“The main issue with this specific project was that it was an incredibly difficult area to access. Here the collision-tolerance feature of the drone meant it was able to access the affected area quickly and reliably,” says Zinn. The new Elios SkyEye drone has a few aspects to its collision-tolerance feature, one being the carbon-fibre frame around the actual drone. The frame protects the blades, payload, cameras and lighting system from damage, and is one of the unique features of the drone. Aside from being collision-tolerant, the drone is designed to withstand a certain degree of collision. For example, flying into a tight corner where contact is made with the surface being inspected, the pilot can manoeuvre around it and focus the camera on whatever he wants to look at without the drone actually being damaged, which is very difficult to do with other drones.”
Zinn adds that a new feature includes software that have distance sensors which either allow you to manoeuvre the cage or framework right up against the structure, or if you want to stay a set distance away you can pre-set that. For example, the operator can programme the drone to keep a distance of exactly 1m away from the surface, and fly left or right or up and down, which prevents the drone from going too close.
Flight path challenges
Zinn says that one of the biggest challenges is probably where the drone gets snagged on a piece of wire or stuck somewhere and then the operator is unable to fly it home. They overcome this by proper planning and preparation and ensuring a high level of operator competency.
In general, the operators draft a proper flight plan before they fly, so they know exactly where they will be flying, when they will be flying and the potential dangers or snag points. Plotted on the flight plan is how much time they need to get to the target area, the battery life available, and how often batteries need to be changed. Hence, just through proper planning, most of the challenges associated with extremely inaccessible areas can be overcome. Of course, with a range extender, the drone can also venture a lot further than what is normally possible.
Zinn stresses that what is important is the natural synergy between drones and the rope access. The Elios SkyEye drone picks up or identifies problems that require further investigation, following which, rope-access technicians can carry out any repairs or remedial actions that may be required. “Drones provide an alternative ‘pre-means-of-access’, as well as supplementing our rope access and other services,” he says.
Zinn says, “To qualify to fly the Elios Sky Eye drone, we sent our chief pilot to the manufacturer – Flyability in Switzerland. He obtained all of his qualifications over there, and we then trained the new pilots here in South Africa. The fully-qualified and trained pilot means that the inspection work itself is carried out rapidly and professionally, producing real-time results for the client.
“The Elios SkyEye drone has dramatically improved the health and safety of on-site crews in projects such as this one, allowing specialised teams to enter only once the situation has been thoroughly inspected, analysed and verified. If need be, rope access is then used for teams to carry out additional inspection services such as ultrasonic wall thickness testing or other non-destructive testing methods,” he concludes.
Upgrade by local inventors is slogging it out!
BMG’s Slogging Hammer and Wheel Slogger, which form part of the company’s extensive range of tools and equipment, have recently been upgraded by local inventors, Slogging International, for greater efficiency and improved safety.
“The versatile Slogging Hammer and Wheel Slogger series, which is used in many industries to loosen and tighten bolts and nuts quickly and easily, ensures highly-efficient operation and safe use for operators,” says Andrew Johns, business unit manager, tools and equipment – BMG.
“Recent advancements include a combination of two sizes, a new safety clip on the Slogging Hammer that prevents the shaft from sliding out when the tool is not in operation and an all-in-one torqueing clip on the Wheel Slogger. This new clip allows the user to leave the tool attached to the wheel and gives the option of selecting different torque settings – from 450 to 650Nm – without having to change the clip. Previously each torque was specific to a particular clip.
“There are many advantages of using the Slogging Hammer and Wheel Slogger over conventional slogging methods. Productivity is significantly improved through the controlled and effective impact between the hammer and the spanner, resulting in minimal downtime when compared with other conventional methods of loosening and tightening nuts and bolts. Safety, irrespective of the industry or application, is non-negotiable and the Slogging range ensures a better working environment. Properties include ergonomics, high power to weight ratio and single operator deployment. When the Slogging Hammer is used in combination with the Wheel Slogger, applications are extended.
“Conventional hammer and slogger spanner systems require two operators to tighten and loosen nuts and bolts. This method is not only dangerous when the working area is cramped and there are other people in the vicinity, but it is also unsafe for the operator holding and guiding the slogging spanner. The operator is then at risk of shrapnel and is effectively at the mercy of the operator swinging the hammer.
“The Slogging Hammer was developed to overcome the hazards associated with the traditional hammer and slogging spanner method and to improve operator safety when loosening bolts and nuts. Other uses for this tool include pin extractions, and with an adaptor can be used with standard impact sockets, tyre bead breakers, as well as in the removal of coal picks and other custom chisels.”
Safety features of the Slogging Hammer include a built-in hand-grip, which means there is no need for the operator’s hand to be near the impact zone and an eye-bolt prevents accidents in overhead working conditions, when tightened. No heavy lifting is necessary, as only the shaft weight needs to be managed. This tool is used easily in confined spaces and in areas that are difficult to access. The Slogging Hammer provides greater direct impact, ensuring that the job is completed quickly and safely, with fewer blows than with conventional methods.
When a Slogging Hammer is applied in the Wheel Slogger variation, a single operator is able to safely loosen, tighten and torque wheel nuts for the quick release and replacement of a damaged tyre. The operator can be confident that when the required torque for the application, as prescribed by the OEM manufacturer, has been applied through the Wheel Slogger with its new torque clip, the installed torque will be within 5% accuracy of a torque wrench applied to the same joint. This system mitigates the risk of damage to wheel studs through over-tightening.
All torque settings on the tool are controlled by OEM-specified torque clips, which means that calibration is not required, even after years of usage. Standard torque settings are 450, 550, 600 and 650Nm, however, custom torque ranges up to 1 000Nm can be accommodated on request.
This system has been well received by all sectors, and there is minimal downtime and no need to incur the costs of calling for assistance to change wheels.
BMG’s extensive branch network offers a technical advisory and support service to ensure the suitable product is selected and correctly used for each specific application.
Better, quicker, simpler: gas and vacuum leak detection
COMTEST’s new Fluke ii900 is a handheld sonic industrial imager that enables maintenance teams to quickly and accurately locate air, steam, gas and vacuum leaks in compressed air systems.
The straightforward, intuitive interface allows technicians to isolate the sound frequency of the leak to filter out background noise. In a matter of hours, the team can inspect the entire plant, even during peak operations.
Specifically designed for industrial maintenance teams, maintenance leads, plant maintenance managers and plant operations managers who rely on compressed air, gas or vacuum in their routine operations, this industrial imager offers a new way to locate issues using sound.
SoundMap is displayed in colour over a visual image of the equipment allowing for fast visual location. With the visual image, it is easy to scan a large area quickly and even possible identify leaks from a distance.
The Fluke ii900 can be applied in the following industries:
- Manufacturing: aerospace, automotive, glass, machinery, instrumentation and appliances, plastic and rubber, mining and mineral processing
- Process manufacturing: cement, chemical processing, food and beverage and pulp, paper and wood
The ii900 enables users to do more with existing air compressors, such as:
- Delays the capital expense of purchasing an additional compressor
- Ensures proper air pressure to pneumatic equipment
- Lowers energy costs (optimisation of compressed air budget)
- Reduces leak detection time
- Improves reliability on the production line
The ii900 makes leak detection part of a typical maintenance routine, for example, the training of a maintenance team is possible in a matter of minutes and provides for the validation of repairs.
Finally, with minimal training, technicians can start checking for air leaks as part of their typical maintenance routine. The ii900 means a better, quicker, simpler way to check compressed air leaks, and at the same time conduct gas and vacuum leak identification.