Machine Guarding

Machinery Safety

Presented by Paul Laidler

TÜV SÜD Product Service Slide 1 Machine Guarding Webinar 24/09/2013

Machinery Division

• Assistance in meeting the requirements of machinery safety legislation

– Machinery, Low Voltage and Electro Magnetic Compatibility (EMC)

Directives

– Work Equipment Directive – PUWER and LOLER

• Comprehensive risk assessments

• Guidance on technical file construction and declaration of

conformity/incorporation

• Pre-purchasing CE Audits

• Safety Related Control System validation


Formal Training

• 3 University Certificate Courses in Professional Development:

– European Machine Safety Requirements

– Electrical Machinery Safety

– Functional Safety • Accredited by the University of Teesside


Machinery Safety Engineering Services

• Engineering design

– Site survey and function design specification

– Factory acceptance test

– Installation and commissioning

• Machine guarding

– Design, manufacture and installation of machine guarding and Safety

Related Control Systems

– Solutions include perimeter guarding, light curtains, scanners, interlocking

etc.


Risk assessment

1. Determine the limits of the machine

2. Hazard identification

3. Risk estimation


Determine the limits of the machine

• Use limits

• Space limits

• Time limits


Limits of machine – Use limits

• Use limits – Personnel operating the machine how competent/what age? any impairments –

visual/hearing/physical? male/female?

– Other personnel in the vicinity other operators non-operator employees non-employees


Limits of machine – Space limits

• Space limits

– Physical limits of the machine to

be assessed

– Range of movement

– Space requirements for

operation and maintenance


Limits of machine – Time limits

• Time limits

– ‘Life limit’ – general wear and tear

– Maintenance intervals

– Housekeeping


Hazard identification

Mechanical


TÜV SÜD Product Service Slide 12

Control Measures

• Design the hazard out.

• Remove the need for man machine interface.

• Design in safeguards.

• Reduce the possibility of occurrence.

• Reduce the degree of harm.

• Warn and inform (but only if you can achieve adequate safety).

Hierarchy Of Control

Machine Guarding Webinar 24/09/2013

Risk reduction

HIGH

LOW

RIS

K

INITIAL

DESIGN

DESIGN

OUT

HAZARDS

RISK

REDUCTION

PROTECTIVE

MEASURES

RISK

REDUCTION

TRAINING

ORGANISATION

SAFE SYSTEMS

OF WORK

RISK

REDUCTION

SAFETY

CONTROLS

RISK

REDUCTION

INFORMATION

RISK

REDUCTION


Design out the hazards

• Mechanical risk reduction involves removing or reducing to a minimum trap, nip or pinch points.


Risk reduction

HIGH

LOW

RIS

K

INITIAL

DESIGN

DESIGN

OUT

HAZARDS RISK

REDUCTION

PROTECTIVE

MEASURES

RISK

REDUCTION

TRAINING

ORGANISATION

SAFE SYSTEMS

OF WORK

RISK

REDUCTION

SAFETY

CONTROLS

RISK

REDUCTION

INFORMATION

RISK

REDUCTION


Protective measures (Guarding)

To prevent access


To reduce risks from debris and ejected parts



To reduce risks of damage from outside (e.g. FLT’s)

Barriers



Risk reduction

HIGH

LOW

RIS

K

INITIAL

DESIGN

DESIGN

OUT

HAZARDS

RISK

REDUCTION

PROTECTIVE

MEASURES

RISK

REDUCTION

TRAINING

ORGANISATION

SAFE SYSTEMS

OF WORK

RISK

REDUCTION

SAFETY

CONTROL

S

RISK

REDUCTION

INFORMATION

RISK

REDUCTION


Safety circuits guards


De-energise the machine

Allows the gate lock to be unlocked



Risk reduction

HIGH

LOW

RIS

K

INITIAL

DESIGN

DESIGN

OUT

HAZARDS RISK

REDUCTION

PROTECTIVE

MEASURES

RISK

REDUCTION

TRAINING

ORGANISATION

SAFE SYSTEMS

OF WORK

RISK

REDUCTION

SAFETY

CONTROLS

RISK

REDUCTION

INFORMATION

RISK

REDUCTION


Information

• Information may take the form of:

– manuals for operation, maintenance

and safety;

– drawings and parts lists;


Information

Notices, can be of several forms

such as warning, mandatory and

prohibition

Service information


Risk reduction

HIGH

LOW

RIS

K

INITIAL

DESIGN

DESIGN

OUT

HAZARDS RISK

REDUCTION

PROTECTIV

E

MEASURES

RISK

REDUCTION

TRAINING

ORGANISATION

SAFE SYSTEMS

OF WORK

RISK

REDUCTION

SAFETY

CONTROL

S

RISK

REDUCTION

INFORMATION

RISK

REDUCTION


Training, Organisation and SOP

Organisation includes:

– a coherent Health and Safety structure,

– a management structure with clearly defined responsibilities,

– an involved workforce,

– safe systems of work.


• Machinery Directive

2006/42/EC

Legislation


HSE Horse



• 1.3.7 Risks related to moving parts

• The moving parts of machinery must be designed and constructed in such a

way as to prevent risks of contact which could lead to accidents or must be

fitted with guards or protective devices.

• 1.3.8 Choice of protection against risks arising from moving parts

• Guards or protective devices designed to protect against risks arising from

moving parts must be selected on the basis of the type of risk.

Machinery Directive EHSR’s



• 1.4.1 General requirements

• Guards and protective devices must:

− be of robust construction,

− be securely held in place,

− not give rise to any additional hazard,

− not be easy to by-pass or render non-operational,

− be located at an adequate distance from the danger zone,

− cause minimum obstruction to the view of the production process,




• 1.4.1 General requirements cont

• In addition, guards must, where possible, protect against the ejection or

falling of materials or objects and against emissions generated by the

machinery.




• 1.4.2.1 Fixed guards

• Fixed guards must be fixed by systems that can be opened or removed only

with tools.

• Their fixing systems must remain attached to the guards or to the machinery

when the guards are removed.

• Where possible, guards must be incapable of remaining in place without

their fixings.




• 1.4.2.2 Interlocking movable guards

• Interlocking movable guards must be designed in such a way that the

absence or failure of one of their components prevents starting or stops the

hazardous machinery functions.




To prevent access



• 1.6.4 Operator intervention

• Machinery must be so designed, constructed and equipped that the need for

operator intervention is limited. If operator intervention cannot be avoided, it

must be possible to carry it out easily and safely.




• Machinery Directive

2006/42/EC

Legislation


• Which serves to fulfil a safety function,

• which is independently placed on the market,

• the failure and/or malfunction of which endangers

the safety of persons.

Definition of a Safety Component


Safety devices that fall under the scope of the Directive Annex V Indicative list:

• Extraction systems.

• Guards and protection devices.

• Control devices for calling lifting appliances and anti fall devices for hoists.

• Protective devices designed to detect the presence of a person.

• Safety belts and seat harnesses.

• Hydraulic non return valves where they are used to prevent falls.

Definition of a Safety Component



• Provision and Use of Work

Equipment Regulations 1998

Legislation



• Regulation 5 Maintenance (1) Every employer shall ensure that work equipment is maintained in an

efficient state, in efficient working order and in good repair.

(2) Every employer shall ensure that where any machinery has a maintenance

log, the log is kept up to date.

PUWER 98 Regulations



• Regulation 11 Dangerous parts of machinery

(1) Every employer shall ensure that measures are taken

(a) to prevent access to any dangerous part of machinery or to any rotating part

or

(b) to stop the movement of any dangerous part of machinery or rotating part

before any part of a person enters a danger zone.

PUWER 98 Regulations


Q Is there access to dangerous parts of machinery?

Q Are all guards securely held in place?

Q Can the guarding be bypassed or disabled?

Q Are interlocks fitted, positive acting, correctly positioned and

functional?

Dangerous parts of machinery


R11 – Dangerous parts of machinery


Use of Standards



Machinery manufactured in conformity with specified published European

Harmonised standards will be presumed to comply with the Essential Health

and Safety Requirements covered by those standards

The Role of EN Standards



Many of the Standards now utilised in Europe are now globally recognised

standards

ISO

IEC

The Role of EN Standards Globally



• “A” type apply to all machines

• “B” type are designed to promote safety and split into “B1” and “ B2”

• “C” type apply to a specific type of machine

Types of EN Standard



TYPE C

STANDARDS

for Machines

BS EN 12100- 2010

Safety of machinery, general principles for

design and risk assessment.

BS EN ISO 13857

Upper and Lower limb access.

PR EN 418

Emergency Stop

SPECIFIC PROTECTIVE

DEVICE STANDARDS

2 Hand Controls

Light Curtains

Safety Switches etc

IEC 60204 - 1

Electrical

Equipment

BS EN 414

Safety of machinery

Rules for drafting and

Presentation of safety

standards

BS ISO 13850

Emergency Stop




Type A Standards

• Applies to all machinery and are essential reading for machinery builders

and modifiers

• BS EN ISO 12100:2010 Safety of Machinery – General principles for design

– Risk assessment and risk reduction (ISO 12100:2010)




'B1' Standards

• Apply to all machinery and are designed to promote the essential factors mentioned in the foreword.

'B2' Standards

• These are "apply when used" Standards, i.e. if a particular safety device is chosen for a machine, then it must, be manufactured to the relevant standard. E. g. Interlock switch, E stop switch.




Type C Standards

• BS EN 415 Series Safety of Packaging Machines

• BS EN 10218 Industrial Robots Recommendations for Safety. Parts 1 & 2.

• BS EN 12417 Safety of Machine tools Machining Centres.

• BS EN 692 Mechanical Presses




• Scope

• This International Standard establishes values for safety distances in both

industrial and non-industrial environments to prevent machinery hazard

zones being reached. The safety distances are appropriate for protective

structures. It also gives information about distances to impede free access

by the lower limbs.

BS EN ISO 13857



• Use of Tables

• Reaching over protective structures:

• Table 1 shall be used where there is a Low Risk

• Table 2 shall be used where there is a High Risk.

BS EN ISO 13857



BS EN ISO 13857



• This standard enables users to avoid hazards from crushing

zones. It specifies minimum gaps relative to parts the

human body.

BS EN 349



BS EN 349



SCOPE

• This standard specifies general requirements for the design and construction

of guards provided to protect persons from mechanical hazards.

BS EN 953



Risk assessment

• In order to select and design types of guards appropriate to particular

machinery, it is important to assess the risk arising from the various hazards

present at that machinery and the foreseeable categories of persons at risk !

• see EN ISO 12100

BS EN 953



Enclosing Fixed Guard


• Guards are used for numerous reasons including.

• Containment of ejected parts

• Containment of hazardous substances

• Noise reduction

• Radiation containment

• Explosion (blast panels designed to dissipate force)

• Viewing of process

BS EN 953

Machine Guarding Webinar 24/09/2013 TÜV SÜD Product Service Slide 69


Distance Guarding - Fixed



• Guards must be suitable for purpose.

• Guards shall be designed so far as is practicable to take into account

foreseeable use and reasonably foreseeable misuse.

• Guards shall be designed so as not to cause hazardous crushing or trapping

points, with parts of the machine or of other guards.

BS EN 953



Combination of Guards & Protective Devices



Distance Tunnel Guard



• Guards should be selected from the following in the order of priority given:

a) Local guards enclosing individual danger zones if the number of danger

zones to protect is low. This can provide an acceptable residual risk and

permits access to non-hazardous machine parts for maintenance, setting,

etc.

b) A guard enclosing all the danger zones if the number or size of the danger

zones is high. In this case setting and maintenance points should, as far as

possible be located outside the guarded area.

BS EN 953 Selection of guards



Suitability of guards



• A protection device or interlocking system should be designed so that it will only

operate as intended.

• Furthermore, if a component deteriorates or fails, the device or system should

as far as possible fail in a safe manner by inhibiting the dangerous action of the

machine.

Safety Related Control System


EN 13849


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END


Machine Guarding

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