Risk Assessment of the Machine Friction Welding Equipment

Project name: / friction welding equipment 120 tons

,Risk assessment of the machine "friction welding equipment"

Moderator/ author

Name / Department / Comment
John Doe / Mechanics / Takes notes

Participants

Name / Department / Date, signature
John Doe / Mechanics
Electrical
Fluid technology
Software
Documentation

Document – history

Version / Date / Amendments / Name / Department
0.1 / 01.01.2011 / John Doe / Mechanics
0.2 / 01.10.2011

Risk assessment table of contents

1Project data......

1.1Description of the machine......

1.2Operating modes of the machine......

1.3Determining the applicable directives and standards

2Definition of machine sections......

2.1Overview......

2.2Machine section "Workspace"......

2.3Machine section "Hydraulics"......

2.4Machine section "Handling"......

2.5Control system (machine section)......

3Risk assessment......

3.1Risk assessment tools......

3.2Machine section "Workspace"......

3.2.1Transportation......

3.2.2Operation (and commissioning):......

3.2.3Maintenance......

4Safety functions......

4.1Methods for determining the required safety integrity

4.2Machine section 1: "Workspace"......

4.2.1Transportation ( no SIL specification required)

4.2.2Operation and commissioning: Safety function according to Chapt. 3.2.2......

4.2.3Maintenance: Safety function according to Chapter 3.2.3

1Project data

Rev. / Modification contents / reason for change
0.9 Draft / Plant modernization
Agreement no.
Project / Friction welding equipment 120 to
Plant
Area
Equipment
Doc type / Internal / Referenced document/
Additionally applicable documents:
Doc title / Risk assessment / Substitute for
Risk assessment / Replaced by
Language(s) / EN
Customer specific:
Original manufacturer: "Logo"
Name / Date / Signature
Created by
Checked by
Approved by

1.1Description of the machine

Manufactured item: / "Machine"
within the meaning of Machinery Directive 2006/42/EC Article 2 / (a)
Name of the machine: / Friction welding machine 1200 kN
Type of machine: / Friction welding machine RS120
Year of commissioning: / June 2011
Customer: / In-house requirement
Installation site: / Contract welding
Project code: / RS -23456
1 / Machine limits, intended use / Description / Related documentation
Intended purpose / The RS 120 friction welding machine is used for the friction welding of rotationally symmetrical metal components.
Min. Max.
Process force 90 kN 1200 kN
Machinable full cross-sections Ø 43 mmØ 102 mm
Machinable tubes Ø 50 x 12 Ø 180 x 14
Frictional Rotational speed700 min-11100 min-1
Friction area: 1400 mm²7900 mm²
Component length in spindle 80 mm 450 mm
Component length in center clamp230 mm2700 mm
Use outside the areas mentioned is not permitted!
For usable combinations of materials see weldability matrix in the appendix to the operating instructions
Material preparation: Free of remnants/residuals (If not confirmed, operator has to perform contaminant measurements to find out whether additional action is required) / Operating instructions
Other machine documentation
Guide for welding parameter monitoring (QM3000 control panel)
Add to operating instructions
Weldability matrix in the appendix to the
operating instructions
Predictable use other than intended (misuse / abuse) / All processes other than friction welding and the immediately following trimming of the friction welded components are not permitted
The friction welding machine may only be used if free of technical defects and as intended with an awareness of safety issues and hazards and in accordance with the operating instructions. The software used is tailored to the specified areas of use. Errors, particularly those that can interfere with safety, have to be corrected promptly.
Mechanics: Exchange of spindle bearings, brake disks is not permitted
Component sizes not conforming to the specification may be welded only after consultation with the manufacturer
Note regarding component imbalance:
Welding out-of-balance components which are clamped in the spindle chuck leads to increased bearing wear.
Large imbalances can lead to damage of the control, PC or visualization because of strong vibrations in the machine. / Add to operating instructions
(Note: Include in maintenance guide: User may not exchange spindle bearings and brake disks)
Add to operating instructions
Add to operating instructions
Application limits / Environmental conditions:
EMC; network form; installed height; temperature range, humidity; installation site (hall or outdoors); / Operating instructions "Technical data"
Space limits / RS120 friction welding machine and the work area up to 2 m around the machine.
A loading device such as a chain hoist or pulley which are provided on the building site, are not part of this safety guide / Installation drawing
Add to operating instructions
Time limits / Anticipated life of machine:
150,000 operating hours.
The life of the switching devices depends on the frequency of switching, i.e. largely on its application.
e.g. switching cycles of a contactor = 1,000,000
With a 3-shift machine operation, the life of this machine would be about 3-4 years.
The SPS components are usually not subject to wear,
however, after about 10-15 years, manufacturers will probably discontinue the delivery of spare parts.
The procurement of classical hydraulic components such as control valves, pressure relief valves, etc. is ensured over very long periods of time. (designs and compatibility have been consistent for more than 30 years)
A systematic performance of preventive maintenance can prevent major mechanical breakdown.
(checking oil levels as well as oil quality is part of regular maintenance)
The spindle bearings (ball bearing) should be replaced with new bearings if the noise level or vibrations increase or if the optionally available bearing measuring device is triggered. / Maintenance guide
Operating instructions
Note in operating instructions
Note in operating instructions
Creating a spare parts inventory is recommended
Note in operating instructions
2 / Use environment / Description / Related documentation
Private / No
Commercial / Yes
3 / User groups / Task / Qualification / Related documentation
Technical personnel
Maintenance technician
Industrial electrician
Machinist
Machine operator / Operating, setting up, maintaining
Repair
Setting up the machine for the required friction welding process
Allow refusal of unsafe instructions of third parties / Application-specific training
Training for maintenance technicians
Electrician
Fluid technology specialist
Trained in welding technology
Non-technical persons / No / No
Trainees / No / No
Children (list age group) / No
Older people (no longer able to work) / No
Handicapped persons (persons with limited mental and physical abilities) / No
4 / Materials / Material / Use / Related documentation
Hazardous materials / Hydraulic oil (allergy, water)
Lubricants (allergy, water) / Manufacturer's safety data sheet
Hazardous substances / No / Note in the operating instructions that residuals are excluded from material preparation and material combinations
Hazardous processed materials / No
5 / Life-cycle phases / Description / Related documentation
Transportation, assembly and installation / Transporting the machine or machine assemblies to a different location inside or outside the plant / Work instruction for personnel
Description of tools to be used
in the operating instructions
Commissioning / Installation, setup, testing, teach-in/programming, start-up, all operating modes, machine loading, removal of product from machine, shutting down machine, shutting down machine in an emergency, restart after shut-down, troubleshooting / Operating instructions
Use / Operation / Setup, testing, retooling, start-up, all operating modes, machine loading, removal of product from machine, shutting down machine, shutting down machine in an emergency, restore operation after jam, restart after shut-down, troubleshooting (operator intervention) / Operating instructions
Maintenance / Cleaning and housekeeping, maintenance
Troubleshooting (operator intervention), / Operating instructions
Decommissioning, dismantling, disposal / At manufacturer's plant or at customer's installation site by customer's employees / Operating instructions
Safety data sheets
Operating supplies
Additional special life-cycle phase / None

1.2Operating modes of the machine

The following overview shows examples of possible operating modes:

Operating mode (name) / Abbreviation / Description (e.g. functionality)
Automatic mode / Auto / Pre-heating, friction welding and cooling below setting temperature
Manual mode / Manual / Clamp, load, remove parts
Setup mode / Setup / Change chuck
...
All / All / Applies to all operating modes described here
Independent / None / This life-cycle phase does not have an operating mode

1.3Determining the applicable directives and standards

Directive / Directive no. / Applicable
YesNo
Machinery Directive / 2006/42/EC / X
Applicable standards:
EN 12100-1, EN 12100-2, EN 14121-1, EN 349, EN 60204-1, EN ISO 13849-1, EN 62061, EN ISO 13857, EN 13855, EN ISO 13850, EN 1088, EN 953, EN 982
Electromagnetic Compatibility / 2004/108/EC / X
Applicable standards:
EN 60349
Low Voltage Directive / 2006/95/EC / X
Applicable standards:
EN 60204-1
Equipment and protective systems intended for use in potentially explosive areas / 94/9/EC / X
Applicable standards:
Pressure Equipment / 97/23/EC / X
Applicable standards:
EN 982
Simple pressure vessels / 87/404/EEC / X
Applicable standards:
EN 982, EN 13445-6 (suppliers)
Outdoor Equipment Noise / 2000/14/EC / X
Applicable standards:
Eco-design of energy-using products / 2005/32/EC / X
Applicable standards:
…
Applicable standards:

2Definition of machine sections

2.1Overview

Legend:

Module namesNames of work areas

Notes:

Keyword / Description
Operator doors / For visibility reasons, the "operator doors" which secure access to the "machine work area" are not shown in the above view.
Maintenance doors / All other doors are "maintenance doors" which do not have to be opened during cyclic operation of the machine.

Definition of machine sections:

Machine sections / Description
Workspace / Machine interior which is protected by the operator doors.
Hydraulics / Hydraulic unit as well as hydraulic lines and blocks in the machine.
Handling section / Area in front of the machine for handling components.
Control system / Control cabinet with control, operator console with PC and the general electrical equipment of the machine

2.2Machine section "Workspace"

Hazard zone / Comments
Spindle chuck with clamping jaws / Sputtering grease; manually locking workpiece in position; locking clamping jaws after exchange
Facing tool / Heat of drive motor, cutting twist-off tool
Center clamp / High force due to hydraulic activation, crushing risk
Steady rest / High force due to hydraulic activation, crushing risk
Compression stop - lateral displacement: / Grip; slipping during transportation (lock in place), use loading device when retooling compression stop
Work cradle / High force due to hydraulic activation, crushing risk; transport guide; residual oil level, bolting together
Spindle drive / Motor; pulley; belt set, unexpected restart, maintenance – temperature; self-ventilated, forced air ventilation
Welding process / Components can also be hazardous; e.g. heat, smoke, ergonomics when loading and unloading, burrs, etc.
Hydraulics / Pump running hot, bursting of pipes or hoses

Relevant hazard sources:

Hazards according to EN ISO 14121-1 andEN ISO 12100
Life-cycle phase / Mechanical / Electrical / Thermal / Noise / Vibrations / Radiation / Substances / Ergonomics / Environment / Combination
Operating mode
Transportation, assembly, installation / Compression stop
Work cradle
Operation
+
Commissioning
Auto / Spindle chuck
Facing tool
Center clamp
Steady rest
Hydraulics / Spindle drive
Control system / Hydraulics
Spindle drive
Welded parts / Hydraulics
Spindle drive
Welding process / Spindle chuck
Center clamp
Steady rest
Work cradle
Welding process / Compression stop
Center clamp
Manual / Spindle chuck
Turning unit
Center clamp
Steady rest
Compression stop
Work cradle
Hydraulics / Spindle drive
Control system / Hydraulics
Spindle drive
Welded parts / Hydraulics
Spindle drive
Welding process / Spindle chuck
Center clamp
Steady rest
Work cradle
Welding process / Compression stop
Center clamp
Setup / Spindle chuck
Compression stop
Work cradle / Spindle drive
Control system / Hydraulics
Spindle drive
Welded parts / Hydraulics
Spindle drive
Welding process / Spindle chuck
Center clamp
Steady rest
Work cradle
Welding process / Compression stop
Maintenance / Spindle chuck
Facing tool
Center clamp
Steady rest
Compression stop
Work cradle
Spindle drive
Hydraulics / Spindle drive / Facing tool
Hydraulics
Spindle drive / Spindle chuck
Center clamp
Steady rest
Work cradle
Welding process / Compression stop

2.3Machine section "Hydraulics"

Hazard zone / Comments
Hydraulic pump / Setting max. pressure limit, noise generation by pump unit, hot surface.
Filter cooling unit / Describe oil filter exchange in the hydraulic pressure circuit in the instructions
Hydraulic blocks / Setting pressure control valves, notes on valve exchange
Hydraulic pipework / Screw connections may start leaking, drain pipes for transport and seal off ends
Hydraulic hoses / Ageing of hydraulic hoses, possible wear of hoses due to chafing in energy chains or hose packages
Pressure accumulator / Hazard from accumulated pressure in the pressure accumulator, describe operating and maintenance procedures.

Relevant hazard sources:

2.4Machine section "Handling"

Hazard zone / Comments
Component handling / Crushing zones between components and machine parts, ergonomic evaluation of component handling,
Point out loading and unloading devices, point out personal safety equipment
Work area (in front of machine) / Avoid tripping hazards, keep work area free of unnecessary objects, ergonomics: Install pressure-sensitive safety mat, etc.

Relevant hazard sources:

Hazards according to EN ISO 14121-1 andEN ISO 12100
Life-cycle phase / Mechanical / Electrical / Thermal / Noise / Vibrations / Radiation / Substances / Ergonomics / Environment / Combination
Operating mode
Operation
+
Commissioning
Manual / Component handling
Work area / Component handling / Component handling
Work area
Auto / Work area

2.5Control system (machine section)

Hazard zone / Comments
Cable running through the machine / Possible cable damage due to component handling or hot shavings from the turning device
Effects of a control failure / Investigate what could happen if control system or parts of it fail.
Effects of a voltage recovery / Check whether a voltage recovery can cause hazards.
Software error / In case of a software error, the machine will indicate a malfunction if a certain constellation is detected.
Control cabinet / Unintended switching

Relevant hazard sources:

Hazards according to EN ISO 14121-1 andEN ISO 12100
Life-cycle phase / Mechanical / Electrical / Thermal / Noise / Vibrations / Radiation / Substances / Ergonomics / Environment / Combination
Operating mode
Operation
+
Commissioning
Auto / Cables through machine
Control failure
Volt. recovery
Software error
Manual / Cables through machine
Control failure
Volt. recovery
Software error
Setup / Cables through machine
Control failure
Volt. recovery
Software error
Maintenance / Control cabinet
Dismantling / Control cabinet

3Risk assessment

3.1Risk assessment tools

You can use the risk/measures matrix to evaluate the design and determine the measures required.

Probability of occurrence
Extent of harm / A
Probable / B
Possible / C
Improbable
4 / Irreversible:
Death, loss of an eye or arm
3 / Irreversible:
Broken limbs, loss of finger(s)
2 / Reversible:
Requires treatment by a physician
1 / Reversible:
First aid required
Type of action to be taken / Examples
Design measure / Inherently safe design: Travel limit; cover
Technical safety measure / Separating safety device: Protective fence, door, flap, light curtain, two-hand control panel;
At a minimum, warnings are required / Standardized pictograms: ear protection, etc.
No further action required / Operating instructions; organizational, if needed
Abbreviation / Description of safety measure
C e,f,m / Design (electrical, fluid technology, mechanical)
FS / Functional safety (control measure)  safety function
W / Warning on the machine
BA / Note in the operating instructions or maintenance guide
PPE / Personal protective equipment
ORG / Organizational safety measure

File: Standard solution_Version_1Page 1 of 28

Project name: / friction welding equipment 120 tons
No. / Type of hazard (electrical, etc.) ISO 12100 / Hazard (crushing, shearing, clutching, etc.) 12100 and 14121 (source, consequence)
Description / Other standards / Risk (before) / No. / Measures / solutions
description / Type / Risk (after) / Test criteria

3.2Machine section "Workspace"

3.2.1Transportation

Hazard zone: / Compression stop - lateral displacement: / Operating mode according to Section 1.2 / None
1. / Mechanical / Crushing
Hazards for hands, fingers due to unintentional shifting / 2 B / 1 / Interlocking with retaining bolt / Km / 1 C / Visual and functional inspection
2 / Wearing work gloves / PSA / Review documentation
3 / Work instruction and warning in operating instructions / BA / Review documentation

3.2.2Operation (and commissioning):

Hazard zone: / Spindle chuck / Operating mode according to Section 1.2 / All
2. / Mechanical / Drawing-in or trapping
Rotating spindle chuck and jaws:
Hazard for hands, arms, upper body and head. / 4 B / 1 / Install operator doors (mechanical protection) / Km. / 4 B / Functional testing upon commissioning
4 B / 2 / Install safety switch with holding device / FS / 1 C / Functional testing upon commissioning
3. / Mechanical / Being hurled away
Rotating chuck and jaws:
Hazard from incorrectly fastened jaws or
from components which are not clamped tightly enough. / 3 B / 1 / Enclosure and operator doors must be designed so that a disengaging jaw is kept away from the operator.
Stable door lining, armor-plate glass pane / Km / 1 B / Visual inspection
2 / Appropriate organizational measures must be in place to ensure that the screws for holding the chuck jaws are tightened sufficiently. This requirement can only be met if the set-up person/operator works extremely diligently. / BA / Review documentation
3 / Work instruction and warning in operating instructions / BA / Review documentation
4. / Mechanical / Being hurled away
Reduced tension force if spindle coasts down after power failure / 3 B / 1 / The devices holding the protective covers in place have to be designed so that the operator doors remain locked during a power failure. The hydraulic circuit of the spindle chuck also has to be designed so that the tension pressure will be retained as long as possible.
 Use pilot-controlled check valves or seat valves since they have excellent tightness. Pressure in the direction of the last motion is reduced only after the other direction of motion is actually actuated. / Km
Kf / 1 B / Functional testing upon commissioning
5. / Mechanical / Being hurled away
Generating a clamping pressure which is too low or too high.
If the clamping pressure is too low, the component in the spindle chuck may start slipping. In that case, the jaws of the spindle chuck will spin on the component.
The component may fuse with the jaws of the spindle chuck.
If the clamping pressure is much too low, the rotating part may be ejected from the spindle chuck. (before welding !) / 3 B / 1 / Verify whether the required clamping pressure has actually been reached.
Read actual clamping pressure (analog sensor) and compare with specified pressure (analog value read-out) / Km
Kf / 1 B / Functional testing upon commissioning
6. / Substances / Splashing
Rotating chuck and jaws:
Danger to eyes from splashing lubricating grease / 2 A / 1 / Mechanical guard between rotating spindle and operator in the form of operator door / Km / 1 B / Visual inspection
Wear safety goggles / PSA / Review documentation
Hazard zone: / Turning unit / Operating mode according to Section 1.2 / Auto, manual
2.02 / Electrical / Fatal electric shock
Electric shock from defective cables or damaged drive motors / 4 C / 1 / Ground all components / Ke / 1 C / Visual inspection of grounding
Grounding resistance measurement
3.01 / Thermal / Burns
Glowing shavings flying about / 3 A / 1 / Attach protective covers and operator doors to contain the glowing shavings. / Km / 2 B / Visual inspection
2 B / Wear safety goggles and work clothes / PSA / 1 C / Review documentation
Work instruction and warning in operating instructions / BA / Review documentation
Hazard zone: / Spindle drive ( in spindle drive section, on face of machine ) / Operating mode according to Section 1.2 / Setup
1.01 / Mechanical / Drawing-in or trapping
Rotating pulley and drive belt:
are a danger to hands and arms. / 4 C / 1 / Install safety doors (mechanical protection) / Km. Ke / 4 C / Visual inspection
4 C / 2 / Install safety switches / FS / 1 C / Functional testing upon commissioning
3 / Close mechanical brake when safety door is open / FS / Functional testing upon commissioning
1.04 / Mechanical / Drawing-in or trapping
An excessively high rotational speed of the spindle can damage the ball bearings (lubricating film on rollers and balls may break) and become a hazard for the operator, since the clamping force is reduced as the rotational speed increases if chucks without centrifugal force compensation are used. In the worst case, the component could be ejected from the running spindle chuck. / 4 A / 1 / If the frequency converter malfunctions (rotational speed much too high), the drive should be shut down.
Based on an analysis of the tachogenerator signal, the machine control may perform a stop action.
First, the control signal is removed from the converter. If the rotational speed does not change within a certain time period, the power contactor (between converter and motor) is switched off. / Km. Ke / 3 C / Functional testing
Hazard zone: / Spindle drive ( in spindle drive section, on face of machine ) / Operating mode according to Section 1.2 / All
2.01 / Electrical / Burns
Electrical motors may reach a very high surface temperature of up to 85°C even during normal operation.
 Risk of burns on hand or arms / 3 B / 1 / Install drive motor behind safety covers / Km / 3 C / Visual inspection
3 C / 2 / Perform work on motor only with safety gloves and work clothes / PSA / 1 C / Review documentation
3 / Attach warning labels close to motor / W / Visual inspection
4 / Work instruction and warning in operating instructions / BA / Review documentation
2.02 / Electrical / Fatal electric shock
Electric shock from defective cables or damaged motor / 4 C / 1 / Motor grounding / Ke / 1 C / Visual inspection of grounding
Grounding resistance measurement
2.03 / Electrical / Fire
If welding parameters are set completely wrong, the spindle drive may be overloaded by the process or strained excessively due to mechanical malfunctions. Without appropriate safety measures, this could cause a fire under certain conditions.
An overload of the drive requires a shutdown in case of overload. / 2B / 1 / In case of overload, the drive is shut down by using circuit breakers. The drive is also monitored for overheating using thermistors (measuring the winding temperature) and switched off if indicated. / C / Visual inspection and setting the power value
4.01 / Noise / Discomfort
Noise development from running drive with fan and from rotating drive belt set / 2B / 1 / Install drive motor behind safety covers / C
Hazard zone: / Hydraulic pipework / Operating mode according to Section 1.2 / All
1.01 / Mechanical / Slipping, tripping and falling
Leaking hydraulic oil / 2 B / 1 / Leaking hydraulic lines and other hydraulic components have to be sealed again / Kf / 2 B / Visual inspection
2 / Work instruction and warning in operating instructions / BA / Review documentation
7.01 / Material / substances / Allergies
A high hydraulic pressure and a high number of load changes can result in leakage in the hydraulic screw connections. This may cause splashing of oil which is hot or under high pressure. / 1A / 1 / Visually inspect hydraulic pipework for leaks every 3 months,
retighten leaking screw connections if necessary. / BA / Review documentation
(include in maintenance guide)

3.2.3Maintenance

Hazard zone: / Spindle drive / Operating mode according to Section 1.2 / None
1.01 / Mechanical / Drawing-in or trapping
When checking the spindle belt tension
(manually pushing on the drive belts with fingers), rotating
pulleys and drive belts
are a danger to hands and arms. / 4 C / 1 / Install safety doors (mechanical protection) / Km. Ke / 4 C / Visual inspection
4 C / 2 / Install safety switches
Identical safety function as 3.2.2 / FS / 1 C / Functional testing upon commissioning
3 / Close mechanical brake when safety door is open / FS / Functional testing upon commissioning

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