DGUV Information 209-027 - Machine Tool Fire and Explosion Prevention and Protection

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Annex 2 - Check lists

Extraction systemYesNo
Extraction system suitable for neat oil machining?
(Instructions for use/technical documentation) e. g.:
|_||_|
-Design free of ignition sources|_||_|
-Arc-free fan drive on the intake side|_||_|
-System and ducting earthed|_||_|
Air flow monitored (pressure, flow controls)? |_||_|
-Extraction starts when machine starts|_||_|
-Flow too low: signal indication, machine tool failure indication|_||_|
Extraction capacity adjusted via throttle valve/speed control|_||_|
Extraction system integrated into extinguishing concept:
-Provide sufficient quantity of extinguishing agent in extraction system and separator|_||_|
-If applicable, extinguishing nozzle and fire detection in separator|_||_|
-Consider fan overrun|_||_|
Ducting:
-Slightly inclined without depressions (if applicable, provide MWF drain)|_||_|
-Provide inspection holes/control openings|_||_|
-Regular inspection for deposits, if necessary, cleaning?|_||_|
For ducting system: Prevention of fire propagation, e. g. by means of
-Flame arresters (in pipes and in the machining area)|_||_|
-Shut-off valves (at the machine tool)|_||_|
Effective pre-separation at the machine outlet, e. g. by means of baffle plates, pre-separators|_||_|
Regular maintenance of system and ducting: Maintenance schedule (Instruction handbook)|_||_|
In case of fire: Interruption/extraction by means of
-Fan motor-brake (reduction of overrun)|_||_|
-Automatic shut-off valve|_||_|
Pressure relief deviceYesNo
Route flames and hot gases into safe areas|_||_|
Installation in the cover areas|_||_|
Provide pressure relief area: ~ 0.1 m2/m3 work room (see VDW 3002) |_||_|
Reliable opening at minimal excess pressure (« 5 mbar)|_||_|
Reliable closing subsequent to pressure relief|_||_|
Suitability as protective device verified by the manufacturer (e. g. test)|_||_|
No flammable materials (wooden crates, insulation materials) in the danger zone around the pressure relief device |_||_|
Danger zone warning signs around the pressure relief device|_||_|
Metalworking fluidsYesNo
Low-emission metalworking fluid used?|_||_|
1:Observe characteristics, e. g. in the safety data sheet, product information|_||_|
Example: For MWF with a viscosity of 4.1 [mm/min at 40°C]
-Flash point> 120°C (see Table 1)|_||_|
-Noack evaporation losses [250°C]< 85 % (see Table 1)|_||_|
2:MWF with anti-mist additives (consider filterability)|_||_|
MWF compatible with hydraulic oils, slideway oils (multi-functional oil)?|_||_|
Sufficient quantity of MWF (MWF circuit, storage tank) during machining (see VDI 3035)?|_||_|
No drag-in of large quantities of:
-Cleaning agents and solvents (on workpiece/part) into the MWF circuit|_||_|
-Hydraulic oil into the MWF circuit|_||_|
MWF supply:
-Monitored? (pressure or flow controls)|_||_|
-Sufficient cooling quantity, MWF nozzles?|_||_|
-MWF nozzles arranged in the best possible way?|_||_|
Avoid considerable temperature increase of the MWF
-Increase of MWF temperature by 10°C = doubling of misting|_||_|
-MWF temperature monitored?|_||_|
-Possibility of cooling: e. g. baffle plates, MWF container used sufficiently large?|_||_|
Extinguishing systemYesNo
Use suitable extinguishing agent (consider fire class)|_||_|
Attention:
-For extinguishing gases, e. g. carbon dioxide (CO2) consider danger to personnel (see BGR 134, BGI 888) |_||_|
-For metal fires (magnesium, aluminium, titanium): only use suitable extinguishing agents, e. g. fire class D! |_||_|
-For powder extinguishers: considerable material damage in the interior of the machine tool possible |_||_|
Provide a sufficient quantity of extinguishing agent:
-Also consider extraction system, chip conveyer, holes ....|_||_|
-Consider flow-off losses (e. g. overrun, extraction ...)|_||_|
Extinguishing system:
-Planning and installation: By a specialist company, possibly in agreement with the manufacturerrsteller |_||_|
-Components, planning and installation: consider the state-of-the-art (e. g. VdS Directives..)|_||_|
-Planning and installation: Demand approval test and approval protocol|_||_|
-Positioning: No adverse effects by pressure or flame propagation|_||_|
-Electrical supply and control system independent of machine tool|_||_|
-Interlocking of the extinguishing gas supply during setting and maintenance work (non-electrical or electrical shut-off devices, see BGR 134, BGI 888) |_||_|
-Regular checking of extinguishing agent tanks fill-levels: e. g. pressure controls, weighing devices |_||_|
-Gas extinguishing system: Provide sufficient pressure relief options|_||_|
-Considerable material and environmental damage, personnel injuries: Automatic extinguishing systems! |_||_|
Fire detection and extinguishing:
-Use optical and/or thermal fire detection elements|_||_|
-Fire detection elements: Consider the state-of-the-art (e. g. VdS Directives)|_||_|
-Optical sensors:-consider suitability (e. g. MWF mist)|_||_|
-keep clean (e. g. by air purging)|_||_|
-Thermal sensors:-fire detection slower than with optical sensors|_||_|
-Extinguishing nozzles:-suitable for the relevant extinguishing agent|_||_|
-consider arrangement: if possible, do not direct towards door labyrinths|_||_|
Extinguishing hole and machining area door in case of fire:
-Only to be opened by fire service and specially instructed persons|_||_|
Regular testing of the extinguishing system (see BGR 134) |_||_|
InstructionYesNo
Function and handling of the machine tool and the extinguishing system in case of fire |_||_|
Optical sensors: Avoid light flashes (lighters, welding)|_||_|
Special hazards (NEVER!):
-Opening of the machine door in the event of a fire in the interior: Hazard of backfire|_||_|
-Wearing oil soaked clothing: Fire hazard (wicking) in case of backfire|_||_|
In the case of fires or explosions (BGI/GUV-I 560):
-When the alarm activates: Leave the danger zone immediately|_||_|
-Use escape and rescue routes|_||_|
-Search for help: Fire service, emergency telephone numbers|_||_|
Hazards during ignition of the MWF mixture:
-Violent flame ejections at pressure relief devices/subsequent fires possible|_||_|
-Flame ejection at machine tool door gaps and openings|_||_|
-Extinguishing agent CO2: Hazard of suffocation (above 5 % CO2 volume in air) |_||_|
-During extinguishing process: Ejection of flames in the door area|_||_|
-Hazard of suffocation in confined spaces due to fire smoke and fumes|_||_|
-Do not touch machine components subsequent to fire: Possibly live
(electric shock) and hot (burns)
|_||_|
Reduce fire hazard - Preventive measures:
-Regular emptying of chip container to avoid self-ignition|_||_|
-Regular emptying of machine tool oil pans (extract oil)|_||_|
-No combustible materials (cardboard/carton/oil-soaked rags) in the vicinity of the machine tool |_||_|
-General smoking prohibition: No cigarette ends in chip containers/oil pans|_||_|
Machine toolYesNo
Machine tool suitable for neat oil machining (non water-miscible MWF)?|_||_|
Oil machining dealt with in the "Technical documentation"?|_||_|
Extinguishingsystem present?|_||_|
Extraction system present?|_||_|
Extinguishing system deactivated when machining room door open?|_||_|
Machining room door stays interlocked during machining and emergency stop?|_||_|
Machining room door non-interlockable when the machine is open and switched-off?|_||_|
No oil pool formation in the machining area, drive room or handling area?|_||_|
No oil pool formation in the area outside the machine (oil pan regularly emptied)?|_||_|
Sufficient pressure resistance of guarding?|_||_|
Pressure relief device present?|_||_|
Door labyrinths resistant to outbreak of flames?|_||_|
Other openings (e. g. loading and unloading openings, gaps) in the operating area covered? |_||_|
If applicable, extinguishing hole present?|_||_|
Transparent screens made of polycarbonate undamaged
(see DIN EN ISO 23 125, VDW 0209)?
|_||_|
Transparent screens positively fitted (not with rubber edging)?|_||_|
Alarm device present?Optical|_||_|
Acoustic|_||_|
Marking: Information signs, CO2 hazard warnings, extinguishing system? |_||_|
Machine tool: Control system (example)YesNo
Start of machine:
-Extraction system on/chip removal on|_||_|
-Door interlocked (with guard locking)|_||_|
-Extinguishing system ready to operate (optical and thermal sensors, activation)|_||_|
-MWF supply monitored|_||_|
Extinguishing process:
-For CO2: If applicable, activation delay set (BGR 134) |_||_|
-Extraction system off|_||_|
-MWF supply off|_||_|
-Extinguishing system ready to operate|_||_|
-Doors interlocked (with guard locking)|_||_|
-Alarm device (optical/acoustic) active|_||_|
-Machine drive off|_||_|
Opening of the door:
-Extinguishing system inactive|_||_|
-MWF supply off|_||_|
-Machining process safely stopped|_||_|
-Extraction system: If applicable, keep in mind short overrun!|_||_|