Making sense of risk Risk engineering Asia Pacific

Metalworking operations Metalworking operations

Metalworking operations involve the machine, or nearby, including and oil lines can operate under very high fabrication of ferrous or nonferrous metal overhead building structural elements pressures. products, structural metal products, metal • Flammable or combustible coolants, Nearly every hydraulic oil will combust forgings and metal stampings. They also lubricants, paints, solvents, and under certain conditions relating to its involve a range of other metal and wire hydraulic oils. flashpoint. The flashpoint is the lowest products, such as scientific measuring Ignition sources in metalworking facilities temperature at which a liquid’s vapour and controlling instruments, watches, may include: forms an ignitable mixture in air. (Refer to clocks, jewellery and silverware. • heat from the machining process the Material Safety Data Sheet [MSDS] Although metalworking operations • hot surfaces, such as on ovens, for information including the flashpoint of may appear to be innocuous, every furnaces, torches or exhaust piping a specific oil.) metalworking operation presents hazards • welding operations Oil should never be used in a process specific to its processes, which include • electrical arcing or sparks where operating temperatures approach quenching, cooling, lubrication, dipping, within 30 degrees Celsius of the coating, plasma cutting and hydraulic • smoking materials flashpoint. oil systems. Fires and explosions are of • spontaneous ignition. major concern in these types of facilities It is important to keep ignition sources and are well documented. to a minimum and this involves using Lubricating oil a hot work permit system (refer to systems This guide is designed to assist business the Liberty document Minimising and property owners implement Most metalworking machinery requires property hot work fire risks), providing adequate protection for the building and lubrication. Lubrication oil is often electrical installations in accordance with metalworking equipment in order to help petroleum based and usually operates regional/national codes and appropriate reduce loss exposure, specifically to fire. at lower pressures. Some mist systems, hazardous area classifications, and however, may have higher operating prohibiting smoking in the process areas. Fire hazards and pressures and may require additional protection. ignition sources Hydraulic oil systems The accumulation of oil near machine In most metal fabrication processes, the Metalworking machines typically use gearboxes, in piping trenches and at the following present a potential fire hazard: hydraulic systems to control and drive reservoirs, or the spillage of oil in the • Ignition of metal cuttings, chips or various operations involved in the supply system, can pose a potential fire fines due to an external ignition source manufacturing process. Hydraulic hazard. Routine cleaning, tidying and • Spontaneous ignition of metal cuttings, reservoirs and pumps may be self- regular inspections are critical to ensure chips or fines contained on each machine, or they may that there are minimal oil accumulations • The use of combustible hydraulic or be centrally located, serving several and that all fittings are inspected regularly cutting fluids under pressure machines. Oil reservoirs may have a for leaks. capacity of up to several thousand litres, • Oil deposits or residue on the

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Cutting fluid Petroleum-based fluids Building protection Cutting fluids are designed specifically Petroleum-based fluids under pressure Buildings that house metalworking to cool and lubricate the cutting tools – whether being used for hydraulic operations should be constructed of fire- used in metalworking processes, such movement, lubrication or cooling – resistant or non-combustible materials; a as machining and extrusion. Nearly require protection. This is because building with a wooden roof is therefore every type of machining process benefits a high-pressure oil leak can cause not suitable. Buildings with a large floor from one type of cutting fluid or another, oil atomisation. The atomised oil can area should be subdivided using fire- depending on the material of the work easily ignite, creating a torch-like flame rated construction material. piece. These fluids include oils, oil-water with heat release extending as far as All buildings housing metalworking emulsions, pastes, gels and aerosols 15 metres from the leak. This type of operations should be equipped with (mists). Petroleum distillates, animal fats, fire is difficult to control with a sprinkler automatic sprinkler systems designed plant oils and other raw ingredients are system due to its intensity, the discharge for the type of hazard posed by the used to manufacture cutting oils, many of of fuel under pressure and the three- specific metalworking operation. Certain which are combustible. dimensional configuration. processes may also require local Cutting oil and cooling fluids are usually Sources of hydraulic oil leaks include: application automatic fire suppression applied as a jet or aerosol (mist) which • worn flexible hoses systems. can drift and settle on other equipment, • failure of piping connections Appropriately rated fire extinguishers surfaces, floors and building structures. (particularly where threaded should be provided for each machine, Regular housekeeping and inspections connections are used) and all machine operators should receive are therefore critical, and the following • incorrectly specified hoses training in their use. should be considered: • mechanical damage • Nearby equipment and horizontal surfaces, including floors, should be • valve or packing gland failure. Housekeeping, cleaned regularly. The installation of automatic interlocks maintenance and • Vertical surfaces, such as the sides or remote manual shut-off controls helps training prevent leaks that can lead to a torch-like of equipment and building columns, Housekeeping and preventative fire. The recommended protection for also require regular cleaning because maintenance are of the utmost this type of equipment depends on the fire can burn upwards using the oil importance in the prevention of fire in a size of the reservoirs and the operating accumulation as fuel. metalworking facility. Rigorous, ongoing pressure. When installed, remote manual • Enclosures or extraction systems attention should be paid to the: shut-offs and automatic interlocks should can help prevent the accumulation or • removal of chips, cuttings and fines be arranged to shut off the hydraulic fluid spread of cutting oil and fluids. from the work area pump and the flow from accumulators in • Permanent exhaust ventilation using the event of a leak or fire. • removal of smaller chips and fines non-combustible enclosures or ducting resulting from high-speed operations, can be installed to remove suspended Automatic activation of the interlock can grinding and precise finishing of hard droplets or oil mist. be accomplished using one or more of metals, possibly requiring pneumatic • Some ventilation systems require the following: conveyance automatic fire suppression or • a low-liquid-level switch in the oil • regular inspection for accumulations of explosion-relief panels on their ducts. reservoir oily deposits, fine metal particles and • a pressure sensor dust • flame or fixed-temperature heat • repair of oil leaks as soon as they are detectors installed on the ceiling detected • automatic sprinkler system water-flow • timely removal of any oil switch. accumulations

3 • routine cleaning of walls, floors, blowing down with steam or compressed should be provided for all staff at regular overhead structural members, other air produces a dust cloud and should intervals. vertical and horizontal surfaces, such only be permitted when the area and While adherence to these minimum as equipment, ducts, pipes, hoods, equipment are vacuumed beforehand. procedures may help a business owner ledges, beams and other concealed Training is a priority and all personnel or manager protect their metalworking surfaces, to minimise dust and oil who operate equipment in the premises from fire, they do not accumulations metalworking facility should undergo contemplate every potential scenario for • preventative maintenance of all training. It is essential that this training loss or damage. It is important, therefore, metalworking equipment, following includes: that the property Fire Safety Manager the manufacturer’s guidelines where • the operation of emergency shut-offs should regularly review the placement, available. The implementation of a or fixed protection systems use and maintenance of all metalworking preventative maintenance programme equipment onsite and ensure that the is integral to any metalworking • a thorough understanding of the appropriate safety measures are in place. operation. protective measures in place, and their They should also take responsibility proper operation. It should be noted that when cleaning for ensuring that personnel have Any and all training should be an area and equipment, sweeping or been adequately trained in the use of documented, and refresher training equipment.

Metalworking Hazards and protection at a glance

• Fire is the major hazard but other potential hazards specific • Lubricating/cutting oil and coolant systems – avoid oil to processes should also be considered. accumulation or spread and clean as soon as detected. • Buildings housing metalwork operations should be • High-pressure petroleum-based fluids – install automatic constructed of fire-resistant or non-combustible material. interlocks or shut-off controls. • Automatic sprinkler systems should be appropriate for the • Rigorous tidying and cleaning of work areas and inspection specific operational hazard. and maintenance of equipment is crucial. • Hydraulic oil systems – avoid using in a process with • All personnel should be trained in the safe use of operational temperatures within 30°C of flashpoint. equipment.

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Want more information?

NFPA 70 National Electrical Code.

Australian Standard/New Zealand Standard 3000 Electrical Installations.

Australian Standard/New Zealand Standard 2430 Classification of hazardous areas.

Australian Standard 2118 Automatic fire protection systems.

Australian Standard 1851 Routine service of fire protection systems and equipment.

NFPA13 Standard for the Installation of Sprinkler Systems.

NFPA 16 Standard for the Installation of Foam-Water Sprinkler and Foam-Water Spray Systems.

NFPA 30 Flammable and Combustible Liquids Code.

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All information in this guide is general in scope and, to the best of our knowledge, current at the time of publication. No attempt has been made to interpret any referenced codes, standards or regulations. You should not rely on this information without first obtaining professional advice. © Liberty 2017. Please contact Liberty for a licence to use and distribute this document. This information is current as at November 2017. Liberty means Liberty Specialty Markets, a trading name of Liberty Mutual Insurance Company, Australia Branch (ABN 61 086 083 605) incorporated in Massachusetts, USA (the liability of members is limited); Liberty Specialty Markets Hong Kong Limited (No. 2400200); and Liberty Specialty Markets Singapore Pte Limited (UEN 201538069C) with a branch in Labuan (Company No. LF12903).

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