Overhauling components of hydraulic equipment
Overview
This standard identifies the competences you need to carry out overhauling activities on hydraulic equipment components, in accordance with approved procedures. The components to be overhauled will have been removed from hydraulic equipment, and the overhauling activities will take place in a maintenance environment or manufacturer's workshop.
It includes components such as cylinders/rams/actuators, pumps, hydraulic motors, control valves, pressure intensifiers, accumulators, oil coolers, reservoirs and tanks and other specific hydraulic equipment. The overhauling activities will include carrying out all necessary safety checks, dismantling the equipment to unit or component level, inspecting and checking all components for damage and wear, replacing all `lifed' items and worn/faulty components or units, reassembling the equipment and carrying out all necessary tests/checks.
Your responsibilities will require you to comply with organisational policy and procedures for the overhauling activities undertaken, and to report any problems with these activities, or with the tools and equipment used that you cannot personally resolve, or that are outside your permitted authority, to the relevant people. You must ensure that all tools, equipment, and materials used in the overhauling activities are removed from the work area, and that all necessary job/task documentation is completed accurately and legibly. You will be expected to work with a minimum of supervision, taking personal responsibility for your own actions and for the quality and accuracy of the work that you carry out.
Your underpinning knowledge will provide a good understanding of your work, and will provide an informed approach to applying appropriate overhauling procedures to hydraulic components and equipment. You will understand the dismantling and reassembly methods and procedures used, and their application. You will know how the equipment functions, the common faults encountered, the purpose of the individual components and associated defects, in adequate depth to provide a sound basis for carrying out the overhauling activities, correcting faults and ensuring that the overhauled equipment meets the required specification.
You will understand the safety precautions required when carrying out the overhauling activities, especially those for handling hydraulic fluids. You will be required to demonstrate safe working practices throughout, and will understand your responsibility for taking the necessary safeguards to protect yourself and others in the workplace.
Performance criteria
You must be able to:
- work safely at all times, complying with health and safety and other relevant regulations, directives and guidelines
- follow the relevant overhauling schedules to carry out the required work
- establish the components to be removed and, where appropriate, mark components to aid re-assembly
- ensure that any stored energy or substances are released safely and correctly
- carry out the overhaul to the agreed level, using the correct tools and techniques
- ensure that all removed components are correctly identified and stored in the correct location
- report any instances where the overhauling activities cannot be fully met, or where there are identified defects outside the planned overhauling schedule
- complete the relevant documentation, in accordance with organisational requirements
- dispose of unwanted components, waste materials and substances, in accordance with safe working practices and approved procedures
- deal promptly and effectively with problems within your control and report those that cannot be solved
Knowledge and Understanding
You need to know and understand:
- how to work safely at all times, complying with health and safety and other relevant regulations, directives and guidelines
- hazards associated with carrying out overhauling activities on hydraulic equipment and how to minimise them and reduce any risks
- the importance of following the correct decontamination procedures
- the importance of wearing protective clothing (PPE) and other appropriate safety equipment during the overhaul
- how to use and extract information from equipment manuals, history/maintenance reports, charts, circuit and physical layouts, specifications, symbols used in hydraulic systems, and other documents needed in the overhauling process
- how to carry out currency/issue checks on the specifications you are working with
- the procedure for obtaining replacement parts, materials and other consumables necessary for the overhaul
- terminology used in hydraulic systems, and the use of fluid power diagrams and associated symbols
- the various types of component that make up the hydraulic equipment
- the basic principles of operation of the hydraulic equipment being worked on, and the function of the valves, cylinders/actuators within the circuit
- the sequence to be adopted for the dismantling/reassembling of various types of hydraulic assemblies
- the techniques used to dismantle the equipment to unit or component level, without damage to the components and the need to protect the circuit integrity by fitting blanking plugs/covers
- the identification and application of different types of valves, sensors and actuators pumps static and dynamic seals
- the various mechanical fasteners that will need to be removed and replaced, and their method of removal and replacement
- methods of lifting, handling and supporting the components/equipment during the removal and replacement activities
- methods of checking that components are fit for purpose, and the uses of inspection/measuring equipment
- how to identify defects and wear characteristics, and the need to replace `lifed' and consumable items
- how to check that replacement components have the correct part/identification markings
- how to reassemble the components
- the tools and equipment used in the overhauling activities, and their calibration/care and control procedures
- how to make adjustments to components/assemblies to ensure that they function correctly (such as setting working clearance, setting travel)
- the need to complete the overhaul documentation and/or reports following the overhauling activity
- the procedure for the safe disposal of waste materials, scrap components and hydraulic fluids
- the extent of your own authority and to whom you should report if you have a problem that you cannot resolve
Scope/range
Scope Performance
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- Carry out all of the following during the overhaul of the hydraulic equipment:
- obtain and use the appropriate documentation for the overhauling activities
- adhere to procedures or systems in place for risk assessment, personal protective equipment, decontamination and other relevant safety regulations and procedures to realise a safe system of work
- provide and maintain safe access and working arrangements for the work area
- ensure the safe depressurisation of the hydraulic equipment (where appropriate)
- carry out the overhauling activities, following good practice/approved procedures
- ensure that components and surrounding structures are maintained free from damage and foreign objects
- return all tools and equipment to the correct location on completion of the activities
- Carry out the overhauling activities to component level on four of the following types of hydraulic equipment:
- pumps
- directional control valves
- double acting cylinders
- hydraulic motors
- proportional control valves
- rotary cylinders/actuators
- hydraulic power units
- pressure intensifiers
- reservoirs/tanks
- oil coolers
- pressure regulators
- actuators/rams
- pressure control valves
- hydraulic accumulators
- flow control valves
- single acting cylinders
- other specific components
- Carry out all of the following activities, as applicable to the hydraulic equipment being overhauled:
- cleaning parts prior to dismantling
- pre-disassembly checks and tests
- releasing stored pressure (where applicable)
- draining/removing any remaining fluids
- proof-marking/labelling of components
- dismantling equipment to unit/sub-assembly level
- dismantling units to component level
- checking components for serviceability (such as visual, measurement, NDT, use of probes/scopes)
- removing and replacing components having interference fits (such as by expansion, contraction, pressure)
- replacing all damaged or defective components
- replacing all `lifed' and consumable items (such as piston seals, dust caps, filters, gaskets)
- reassembling equipment
- applying correct lubrication during assembly
- applying gaskets and sealant/adhesives
- making mechanical connections
- setting and adjusting replaced components
- securing components using mechanical fasteners and threaded devices
- tightening fastenings to the required torque
- applying locking and retaining devices (such as circlips, pins, wire locking, lock nuts, stiff nuts, swage nuts)
- fitting blanks to openings to prevent entry of contaminating debris
- Replace/refit a range of hydraulic equipment components, to include eight of the following:
- pipework and hoses
- static and dynamic seals
- rollers
- gauges
- pistons
- housings
- regulators
- gaskets
- spools
- actuating mechanisms
- filters
- sensors
- valves and seats
- plungers
- hydraulic fuses
- diaphragms
- bearings
- spring mechanisms
- other specific components
- Carry out checks and tests on the overhauled equipment, to include three of the following:
- visual inspection for completeness of all operations
- visual inspection for freedom from damage or foreign objects
- check that there is appropriate protection to openings to prevent entry of contaminating debris
- carrying out any `special-to-type' test rig checks (such as leak, pressure, range of movement)
- Overhaul hydraulic equipment, in compliance with one of the following:
- BS, ISO or BSEN standards and procedures
- customer standards and requirements
- company standards and procedures
- equipment manufacturer's requirements