GEMÜ glossary for valves and

automation components

GEMÜ glossary for valves and

Our glossary provides an explanation of around 400 technical terms and abbreviations relating to the pipeline construction sector. It focuses on valves, measurement and control systems and their areas of application.

L1 – L4 more
​Abbreviation for laboratory safety measures The necessary measures for ensuring safety in biotechnological laboratories are listed in the publication "Safe Biotechnology", Part 2 (Leaflet M 056) of the Trade Co-operative Association of the Chemical Industry.
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LAL more
​​Limulus-Amöbozyten-Lysat See also Limulus Test
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Laminar flow more
​A laminar flow is a flow of gases and liquids around obstructions, which does not result in any flow turbulence. This means that the medium flows past the obstruction closely without becoming mixed up.
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Leaching effect more
​Through certain media, low-molecular organic compounds are released from parts of a material. As a result, organic compounds from the piping system enter into the medium.
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Lethality factor (L) more
​Effectiveness of a sterilisation processGermocidal effect at a certain temperature in relation to the germicidal effect of the reference temperature.
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Level more
​The level is the degree of the filling of a container. The level can usually be measured by the height of the medium in the container.
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Limit value more
​Permissible value which, according to laws, regulations, etc. must not be exceeded. According to the TVO, the limit value for the colony count in drinking water is: 100 germs/1 ml; for Escherichia coli (E. coli) in drinking water = 0 germs/100 ml, see also TVO less
Limulus test more
​Method for proving endotoxins by yellowing See also Pyrogenic
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Log reduction more
​Alternative form of the D-value For example reduction by three powers of 10 (10 –3) = log3 or 3D-reduction.
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Long-stroke more
​Term used in linear operating valves, cylinders and combustion engines The opening stroke/piston stroke is longer than the nominal diameter of the valve seat/piston.
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Long-term pasteurisation more
​See also pasteurising
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Low germ more
​Low colony number (germ number). In relation to a product low germ means that the biological stability is statistically guaranteed
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Low pasteurising more
​​See pasteurising
 
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Low pasteurising more
See Pasteurising
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Machine more
​A machine is a connected network of parts of which at least one part is freely maovable. A machine is used to perform technical processing stages and to optimize these in terms of force, time and accuracy.
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Machine more
​A machine is a connected network of parts, of which at least one part is freely movable. A machine is used to perform technical processing stages and to optimize these in terms of force, time and accuracy.
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Machinery Directive more
​This directive regulates the framework conditions for occupational health and safety in connection with machines. It lays down requirements with regard to conformity assessment procedures for persons responsible for machines.
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Manipulated variable "y" more
​Is the value by which the valve is actuated to achieve matching set and actual values.
The manipulated variable can be implemented electrically, hydraulically or pneumatically (depending on the implemented system technology).
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Maximum permissible operating pressure more
​Is the maximum permissible pressure of the working medium defined by the manufacturer for which a component or device is designed and at which the function and operational reliability are still guaranteed.
The maximum permissible operating pressure is always dependent/interactive with the maximum permissible operating temperature and ambient temperature. The interactions in plastic pressurised components are so strong that they must be taken into account and might mean that they cannot be used. In other cases the interactions must at least be checked. A reference temperature for the working medium and the environment of 20 °C usually serves to determine the maximum permissible operating pressure defined by the manufacturer. If the actual temperature of the working medium or the environment deviates from the manufacturer reference, the user must limit the maximum operating pressure accordingly or use more stable components. If the maximum operating pressure is permissible at simultaneously high temperatures, the manufacturer will define this accordingly in the documentation.
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Maximum permissible operating temperature more
​Is the maximum permissible temperature of the working medium defined by the manufacturer for which a component or device is designed and at which the function and operational reliability are still guaranteed.
The maximum permissible operating temperature is always dependent/interactive with the maximum permissible operating pressure and prevailing ambient temperature. The interactions in plastic pressurised components are so strong that they must be taken into account and might mean that they cannot be used. In other cases the interactions must at least be checked. A reference pressure for the working medium and an ambient temperature of 20 °C usually serves to determine the maximum permissible operating temperature defined by the manufacturer. If the actual pressure of the working medium or the ambient temperature deviates from the manufacturer reference, the user must limit the maximum operating temperature accordingly or use more stable components. If the maximum operating temperature is permissible at simultaneously high operating pressure and/or increased ambient temperature, the manufacturer will define this accordingly in the documentation.
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Mean roughness value more
​See Roughness parameters
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Measurement more
Is the comparison of an unknown variable with a similar scaled known variable.
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Measurement device more
​Is a device which continuously measures a mathematical, geometrical, chemical, physical or time variable directly (e.g. thermometer) or indirectly (e.g. turbine flow transmitter), processes it internally in a suitable form if necessary and shows it in a display.
Short definition: measurement is sensing and if necessary processing and displaying.
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Measuring transducer more
​Is a device which continuously measures an electrical variable on the input side, converts it internally and provides it on the output side in another electrical variable as a signal for further processing (e.g. 2-wire measuring transducers which pick up a physical variable on the input side by a potentiometric sensor and provide it as a current signal for further processing on the output side).
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Micro filtration more
Micro filtration is a membrane filtration process which works with pressure. The pore size is > 0,1 µm.
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Micro-organisms more
​Bacteria, yeasts, mould fungi, algae; possibly viruses and bacteriophages.
Examples of dimensions:
Viruses = 17 - 300 µm,
bacteria = 0,2 - 3 µm,
yeasts = 2 - 8 µm.
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Microbiocide more
​Germocidal
Microbiocidic materials have an exterminating effect on micro-organisms.
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MIF more
​Magnetically inductive flowmeter. Through the application of a magnetic field and the voltage occurring as a result of the deflection of the load carrier, which is generated by the flowing medium in a pipe, the flow velocity can be calculated based on its proportionaliy to the voltage.
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MIF more
​​Milk Industry Foundation
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