Foundries

Knock-off, cut-off and fettling castings using:

Large angle grinders

Large straight grinders

Chipping hammers

Pedestal grinders

Eliminate or reduce the need for manual knock-off/cut-off or fettling using, where appropriate:

• good foundry practice and investment casting (lost wax) or lost foam casting techniques to improve casting precision
• design castings to minimise fettling (number of joint lines etc.)
• decrease ingate/feeder size and reduce cut-off time
• design castings suitable for direct machining
• challenge inappropriate customer specifications for high standard of finish

Substitute alternatives to manual fettling using, for example:

• robot fettling machines
• automated grinding and manipulators
• semi-automatic cut off
• cropping machines
• jig-mounting for grinder or castings

Design of casting and runner systems should allow for these methods.

Note: These methods for elimination and substitution will usually be reasonably practicable for large production runs; some may also be appropriate in jobbing foundries.

Hand-arm vibration in foundries (FIAC 2001)

Example: eliminate fettling by improving casting quality

Example: machining as a substitute for fettling.

Example: automatic fettling

Example: jigs for hands free grinding

Example:semi-automatic cut-off

Example: isolated cut-off machine

Example: hydraulic cropping

• Frame-mounted breaker

• water-cooled cupola without lining (for capacity >9 tonnes/hr)
• hydraulic lining “push-out” for furnace lining
• hydraulic machine-mounted breaker;

Reduce the frequency of lining renewal or slag chipping by:

• Maximising life of lining through good cupola operating practice
• Reduce buildup of slag by control of impurities

Foundries Information Sheet 11

Example: hydraulic pushout

Example: ladle slag chipping

Ramming moulds with:

Sand rammers

Electric demolition hammers

In jobbing foundries, where hand-ramming of moulds cannot be eliminated, the risk can be controlled by;

• mounting an electric hammer in a frame on a balancing rig
• mounting a pneumatic rammer in a semi-rigid balancing arm

Tool selection can make a substantial difference to the vibration level but the tool must be suitable for the task and used correctly.

Employers should demonstrate a sound procurement policy for power tools and hand-guided machines, showing they have considered the following:

• There is no reasonably practicable alternative method with no (or less) vibration exposure (see Table 1)
• Equipment is generally suitable for the job (safety, size, power, efficiency, ergonomics, cost, user acceptability, etc.)
• Reduced vibration designs are selected provided the tools are otherwise suitable (e.g. grinders with automatic spindle balancing)
• Declared vibration emission is not high compared with competing machines of similar capacity to do the job
• Information on likely vibration emission in use (e.g. from manufacturer, hire company, databases)
• Available information from the manufacturer or elsewhere on control of vibration risks through:
  • maintenance of tools and accessories (e.g. servicing grinders, sharpening chisels)
  • selection of consumables (e.g. suitable grit size and hardness of abrasive wheels, pitch of teeth on rotary files/burrs)
  • correct operation and operator training (see below)
  • maximum daily trigger times or maximum daily work done with the tool

Selecting equipment

Employers’ leaflet on HAV

Foundries Information Sheet 12

Hand-arm vibration in foundries (FIAC 2001)

Restricting exposure time (“finger-on-trigger” time) may be required to bring exposures below the ELV, even after all reasonably practicable measures to reduce vibration levels are in place.

Maximum times can be determined using the exposure points system or supplier’s “traffic lights” tool categories, but these should be derived from sound “real use” vibration emission values.

Note: Employers tend to ask “How long can we use this tool?” The exposure must be reduced to the lowest level that is reasonably practicable (Reg 6(2)), so the ELV should not be used as a target, if a lower exposure is reasonably practicable.

Reduce the period of exposure

Exposure points system and ready reckoner

Control of HAVS risk by means other than reducing vibration exposure:

• Ergonomic aids such as tensioners or balancers to support weight of tool and reduce forces applied by operator
• Pedestal grinders: mount the work rest independently of the machine, to reduce transmission of vibration
• Suitable workplace temperature or provision of warm clothing and gloves
• Regular breaks from work involving vibration and encourage operators to exercise fingers

Gloves and warm clothing

Other measures

Example: pedestal grinder

Employees’ leaflet on HAV

Employees at risk from vibration should have received information on:

• the risks from HAV and how to help reduce them (see above)
• the importance of correct operation and maintenance of equipment
• arrangements for health surveillance and their duty to co-operate.

Look for evidence that tools are being used correctly, as recommended by the manufacturer. This may require operators to receive specified training – are operators and their supervisors aware of the need? For example, if an unsuitable abrasive is used, operators may resort to “bumping” the grinder against the casting; this can result in distortion of the wheel and increased vibration, and there is also a risk of wheel breakage.

Employees’ leaflet on HAV

Information and training

Hand-arm vibration in foundries (FIAC 2001)

Required where the EAV is likely to be exceeded. Expect to see, as a minimum:

• use of a periodic health screening questionnaire – ideally annually and for new employees
• arrangements for referral of relevant cases to an occupational health provider with HAVS expertise for diagnosis and on-going monitoring
• arrangements to receive medical advice on management of affected employees
• arrangements for RIDDOR reporting of HAVS cases
• arrangements to receive anonymised information to demonstrate effectiveness of controls

Employers’ leaflet on HAV

Health surveillance guidance