Operator safety, CE marking, risk assessment of materials testing machines
Answers for security officers / professionals
The operator safety / operational safety of testing machines and testing equipment is an indispensable prerequisite for their sale and delivery. According to European law, the manufacturer or distributor is obliged to provide a CE declaration of conformity. In order to be able to issue a CE declaration of conformity, EU legislation requires the implementation of a risk assessment / hazard analysis This can/must be made available to the customer/safety officer/safety specialist by the manufacturer. In this, the manufacturer (who has the greatest knowledge of these machines and how they work) must go through and document a hazard analysis process in which all conceivable handling and use are analyzed in order to identify sources of danger, eliminate them or create suitable protective devices. There are countless different products and machines worldwide. Therefore, there is no positive/negative list that specifies exactly which safety equipment and devices are required or must be used for machines and systems. For some areas, there are very detailed requirements and standards (electrics, vehicle technology KBA, fall protection, etc.). However, these regulations are not applicable to a large number of products and their equipment. Therefore, the safety requirements are very strict, but also very general. To help you, here is a link to a website of the
Federal Institute for Occupational Safety and Health (BAuA) – link to website
Paragraph 3 refers to machine movements (all machines, e.g. universal, tensile, compression, bending testing machines, pendulum impact machines, hardness testing machines, presses (punches), grinding machines):
Excerpt – “Limiting Forces and Speeds”: Limit values for forces or speeds of moving machine parts exist only for a few cases, since generalization is difficult due to the large number of influencing factors and conditions.
- For example, a maximum closing force (clamping force) of 150 N is recommended for power-operated (motor, hydraulic, pneumatic) doors and gates. Separating protective devices are generally not considered necessary if the maximum force of moving machine parts is ≤ 150 N and the contact pressure is <50 N/cm² (for example DIN EN 12203).
- For moving parts in automated production systems, DIN EN ISO 11161 gives examples of a “safely” reduced speed for hazardous movements, e.g. <10 mm/s for presses, less than 250 mm/s for robots, <250 mm/s for all non-shearing movements and less than 33 mm/s for hazards caused by shearing movements. (Note: universal testing machines are also used as presses)
Materials testing machines – Safety specifications according to DIN 51233:2014-10
(Simplified short form, limited to static universal testing machines, hardness testing machines, pendulum impact testers)
Sources of danger:
- Sample-related hazard: The different behavior of the samples during the test and in the event of breakage must be assessed, in particular whether they slowly deform plastically, are destroyed in a dangerous explosion and/or spring back like a whip after breaking (plastic ropes, wire ropes, etc.). A general statement about the safety of a material testing machine cannot be made - an individual case test must be carried out here. In addition, samples can be relatively heavy (tensile testing machines with 600 / 1200 or even 2000 kN force) and/or after the test or after opening the clamping device.
- Functional hazards caused by material testing systems: By applying high force, energy can be stored in the loaded sample. Energy can also be stored in the test frame or in the clamping devices.
... or by rapid machine movements: DIN 51233:2014-10: (Content): “For material testing systems that pose a hazard, EMERGENCY STOP devices in accordance with DIN EN 13850 must be provided.
“who pose a risk”?
An emergency stop device is used to immediately stop all machine movements in a dangerous situation. In static universal testing machines, fast movements are generally excluded because the maximum speed is limited to less than <10mm/second. Likewise, the closing movement of power-operated accessories (hydraulic or pneumatic clamping devices) is also significantly smaller than <10mm/second. Although GALDABINI Universal testing machines / INNOVATEST Hardness testing machines are equipped with an emergency stop device: This is NOT mandatory for these machines. Likewise, a safety relay is NOT mandatory (and is usually not installed - can be offered as an option).
The highest risk potential is assumed on the website of the Federal Institute for Occupational Safety and Health (BAuA) for a punch/press, among other things. If this risk potential is transferred to apparently less dangerous equipment (static universal testing machines, hardness testing machines), the general statement can be made: Safe use is given if a safe travel speed of < 10 mm/s is maintained.
material testing machines (universal, tensile, compression, bending, hardness testing machines)
The specified travel speeds (<10 mm/second) are not exceeded by the GALDABINI / INNOVATEST testing machines. Almost all GALDABINI universal testing machines have a maximum speed of 500 mm/min (8,33 mm/s). (Exception: Q2,5 and special machines with higher speeds). The safety requirements of DIN 51223 - 2014 are fully met. Danger from movement can therefore be ruled out.
And finally ... Regarding the risk of crushing caused by machine movement, NONE Safety devices are required, neither an electrically monitored or electrically locked protective housing, nor EMERGENCY STOP devices (which are nevertheless installed) or other safety devices.
An exception are pendulum impact testers (a type of drop hammer) with a falling speed of the pendulum hammer of 5,5 m/s (5.500 mm/s). For these machines, a locked protective housing is mandatory.
For universal, tensile, compression and bending testing machines, a protective housing / locked protective housing is required if ...
If these testing machines are used to test materials or assemblies that
- tear violently (ropes, especially plastic ropes, straps:) The ends fly around uncontrollably and endanger the eyes, etc.)
- brittle, splintering materials (porcelain, glass, carbon fiber composites, hard metal - tensile or compression testing - parts come loose and fly around uncontrollably - risk to the eyes, etc.) Carbon fiber composites, for example, tend to be destroyed explosively. Individual parts of the sample (fibers) can be thrown out at high speed + energy
- Bursting (pressure vessels, filled pressure vessels – parts come loose and fly around uncontrollably – danger to the eyes, etc.)
- Chain inspection (chain rivets, link bolts, links break, come loose and fly around uncontrollably – danger to body, face, eyes, etc.)
- List not exhaustive, please discuss your testing task with our specialist consultant.
In these cases, we are obliged to offer and supply a protective device. But even if no protective housing is required: If you/your safety officer insist, a protective device (protective housing, locked protective housing, light barriers, two-hand control, safety module, etc.) can be offered and supplied optionally for an additional charge. Please speak to our specialist advisors about this.
punching / pressing
All of our punches are designed so that a movement speed of <10mm/second is not exceeded. None of the punches/presses ever delivered by our company exceeds this movement speed. Therefore, any danger is excluded when used as intended. Nevertheless, our punches are equipped with a 2-hand operation.
We hope that this research has been helpful and we are happy to answer any further questions you may have.
With kind regards,
Wolfram Schütz
