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9. Maintenance and repair
9.1 Introduction
9.1.1 Maintenance schedules as recommended by the manufacturer should be adhered to. Equipment for the purposes of controlling health and safety risks should be adequately maintained. Before embarking on any maintenance or repair work, a risk assessment should be conducted, to highlight potential hazards and to specify the control measures that should be taken to minimise the associated risks. This may include isolating the gas and electrical supplies to the equipment. The area should be tested to demonstrate that there is no flammable gas present and that the circuits are indeed dead. Training, assessment and re-assessment of the competence of the maintenance or repair personnel is a key element of a safe system of work during maintenance or repair.9.1.2 Maintenance and repair, whether carried out in-house or by contractors must be adequately controlled, including special measures such as permits to work, where appropriate. Users must ensure that contractors are competent and use a safe system of work during such activities.
9.1.3 Under normal circumstances, before commencing work, the electrical equipment should be isolated, with the fuses removed and isolators locked off with a padlock (with only one key). Regarding live working, Regulation 14 of the Electricity at Work Regulations 1989 13 requires that three conditions are met for live working to be permitted where danger may arise. An assessment procedure for deciding whether to work dead or alive can be found in HSE booklet HSG 85 'Electricity at work: safe working practices'.59 All live working should be controlled by some form of documentation to confirm that the hazardous area has been de-classified for the duration of testing and how it is to be maintained in that condition. Suitable measures must be taken - to include tools suitable for live working, rubber mats, warning signs, restriction of work to suitably competent persons. It is essential to check for gas leaks before embarking on live electrical work, and to use a gas detector during the work to ensure that the atmosphere remains free from flammable gas. Before using gas detection equipment, ensure its integrity and that it is correctly calibrated and any mechanical ventilation is operating as designed.
9.1.4 The maintenance/repair engineer should be protected from the hazards associated with high speed scan units or robots by isolating them and locking them off. This may require a permit to work to ensure that the isolation is secured.
9.1.5 Where hot work or otherwise hazardous work is to be carried out, a permit to work system should be implemented to ensure that the safety measures are in place before work starts. The permit to work is used to specify what work is to be done, who is to do it, what measures have been taken to ensure that the equipment is safe while it is being done. It will lay down the conditions under which the work is to be done, and will entail a formal process for ending the work and returning the equipment to its normal state.
9.1.6 Equipment should only be calibrated by suitably qualified personnel to ensure safe and proper operation - see the manufacturer's recommendations.
9.1.7 It is essential that any maintenance work should not affect the integrity of the equipment or the hazardous area classification - see BS EN 60079 part 17.60 Any components that are replaced should be those manufactured to a standard suited to their application. All maintenance and repair work must not invalidate the electrical equipment certification.
9.2.1 Full details of the recommended maintenance of pipework systems are in BCGA CP435, and this includes weekly inspections by the user and annual inspections by a competent person in accordance with the Written Scheme of Examination. Documentation of such checks is required. A written scheme of examination is required under the Pressure System Safety Regulations for all protective devices and for all pressure vessels and parts of the pipework in which a defect may give rise to danger. This requirement does not apply if each pressure vessel in the system has a product of pressure in bar and internal volume in litres less than 250 bar litres. At the annual maintenance it is normal to test the high pressure installation to the working pressure.
9.2.2 Regulators for gas equipment should be inspected annually by a competent person, and both regulators and flashback arrestors should be replaced at intervals of five years or as recommended by the supplier. Gas hoses and their connectors should be inspected regularly to ensure that they remain in good condition. Cracked or perished hoses must be replaced, and the hoses should be replaced every five years even if apparently in good condition.
9.2.3 After any breakdown in which the pipework has been, or could have been disturbed, it should be leak tested.
9.3 Ventilation System and Dust Disposal
9.3.1 All extraction systems provided for operator protection, including dry extraction systems must be examined every 14 months by a competent person. Dry extraction systems should be regularly monitored to ensure that the plant is operating correctly. This ensures that problems are identified early and will also increase the life expectancy of consumable items since the system can be adjusted at this time to provide maximum performance. The ducting should be examined, cleaned, and the condition of the filter should be monitored, personnel must wear suitable respiratory protection.9.3.2 It is important that the extraction and abatement systems are not ignored, and users must consider these aspects in addition to the spray system. It is important that the system is viewed holistically and maintained as one piece of plant as this will ensure that the plant works at its most effective with minimal downtime and problems.
9.3.3 Cleaning of the booth should be carried out using a vacuum cleaner designed to handle hazardous dusts, fitted with a high efficiency particulate arrestor (HEPA) filter.
9.3.4 When bag changing on dry collection systems personnel will need respiratory protective equipment where there is a risk of exposure to dusts that are hazardous to health.
9.3.5 All waste must be disposed of in a safe and environmentally responsible manner.
9.4 Wet Systems
9.4.1 The water system will become contaminated with the particulate matter in the overspray. For at least part of the year, the temperature of the water will be within the range where bacteria will grow freely, with ideal growing conditions provided by the particulates, and there is therefore a risk of colonisation by legionella pneumophila.17 For this reason, the water system will need to be assessed and if considered a foreseeable risk, adequately controlled. The control regime should include appropriate biocides and regular cleaning and maintenance of the system. A drain-down and clean is an important parts of the control regime. The frequency of such activities will depend on the use of the equipment. Monitoring for micro-organisms using dipslides may be required weekly. The assessment will need to determine these factors. Contaminated water should be treated as hazardous waste.9.4.2 Advice should be sought from a competent contractor in drawing up a written scheme for the care of the system.
9.5.1 All portable and transportable electrical equipment shall be maintained in a safe condition, and tested at regular intervals. Advice is given in the Health and Safety Executive guidance.61 The definition of portable and transportable includes all equipment of 18 kg or less which is not fixed, and heavier equipment that has wheels, etc, to facilitate movement.62 This work should only be undertaken by competent persons.
9.5.2 The fixed installation should also be the subject of an appropriate maintenance scheme in accordance with guidance in BS 7671.50
9.5.3 Records should be kept of all inspections and tests including any tests where new equipment is installed.