Q10 value
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QHD
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Qualified Hygienic Design (test system for cleanability of components)
Stage 1 includes the theoretical proof of hygienic construction. The compliance with these standards relevant for the respective component can be documented by an own certificate and a QHD mark stuck to the component. The manufacturer hereby declares that he has complied with the state-of-the-art with regard to the requirements for a hygienic construction specified in the regulations.
Stage 2 is verified by a standard test developed by the Faculty for Machine and Apparatus Study of the University of Munich, Freising – Weihenstephan. (practical proof of cleanability)
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Stage 1 includes the theoretical proof of hygienic construction. The compliance with these standards relevant for the respective component can be documented by an own certificate and a QHD mark stuck to the component. The manufacturer hereby declares that he has complied with the state-of-the-art with regard to the requirements for a hygienic construction specified in the regulations.
Stage 2 is verified by a standard test developed by the Faculty for Machine and Apparatus Study of the University of Munich, Freising – Weihenstephan. (practical proof of cleanability)
Qualification
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Quenching
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Recommended value
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Regulation
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Relative pressure
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Relief valve
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Resistance
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Reverse osmosis
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Reynolds figure
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Rinsing
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RO
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RoHS
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Roughness depth
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Roughness parameter
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Comparable measured values determined from the roughness profile of technical surfaces by stylus instruments
The following are distinguished according to DIN 4768 Section 2.3:
Mean roughness value Ra = arithmetic mean of the distances between the roughness profile and the middle line within the measuring distance.
Single roughness depth Zi = distance between two parallel lines which touch the roughness profile at the highest and lowest point in a single measuring distance and the middle line.
Averaged roughness depth Rz = arithmetic mean of the single roughness depths of five consecutive measuring distances.
Maximum roughness depth Rmax = greatest single roughness depth occurring on the total measuring line.
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The following are distinguished according to DIN 4768 Section 2.3:
Mean roughness value Ra = arithmetic mean of the distances between the roughness profile and the middle line within the measuring distance.
Single roughness depth Zi = distance between two parallel lines which touch the roughness profile at the highest and lowest point in a single measuring distance and the middle line.
Averaged roughness depth Rz = arithmetic mean of the single roughness depths of five consecutive measuring distances.
Maximum roughness depth Rmax = greatest single roughness depth occurring on the total measuring line.
Sanitation
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Sealing
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Self-draining
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A frequently misused term for the design and construction of a media-carrying component or plant section which enables the complete draining of a pipe system without outside intervention.
The term suggests fully automatic draining. Complete self-draining is not possible in reality, especially because the increased adhesion of a working medium leads to the medium sticking partly to the surfaces of the pipe sections, valves or vessels to be emptied. Actually the optimisation of a plant can merely ensure that a so-called unhindered outlet can take place. Ideally no media residue in the form of puddles or clogged material remains in the pipe. To counteract an increased media adhesion it may be useful to fit transverse pipes and components with an appropriate drop/gradient. This is also recommendable to overcome gravity and define an orderly outlet in direction and time. See also Free outlet and Optimum draining.
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The term suggests fully automatic draining. Complete self-draining is not possible in reality, especially because the increased adhesion of a working medium leads to the medium sticking partly to the surfaces of the pipe sections, valves or vessels to be emptied. Actually the optimisation of a plant can merely ensure that a so-called unhindered outlet can take place. Ideally no media residue in the form of puddles or clogged material remains in the pipe. To counteract an increased media adhesion it may be useful to fit transverse pipes and components with an appropriate drop/gradient. This is also recommendable to overcome gravity and define an orderly outlet in direction and time. See also Free outlet and Optimum draining.
Servo controlled
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The actuation, e.g. a valve actuator, does not control the sealing mechanism of a valve directly but with the aid of the operating pressure applied in the valve. The necessary forces are generated by defined areas and their exposure to the operating pressure. Small control bores and channels serve for this so that relatively high operating pressures can be handled by relatively small actuators (usually electromagnetic). Terms such as forced lift and auxiliary controlled are also used manufacturer-dependently. Servo controls are also familiar for example as steering and brake assistance in vehicles.
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Set value "w"
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Short-stroke
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Signals
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SIL
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SIP
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Smoothness
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Soiling
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Solenoid valve
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Spores
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Germ cells of micro-organisms which are also permanent forms in bacteria.
Permanent form of micro-organisms formed under unfavourable conditions which germinate in a favourable environment, reproduce and survive heating to 75 °C for 20 minutes. Bacteria spores have storage substances and solid, resistant cell walls.
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Permanent form of micro-organisms formed under unfavourable conditions which germinate in a favourable environment, reproduce and survive heating to 75 °C for 20 minutes. Bacteria spores have storage substances and solid, resistant cell walls.
Square-stroke
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Steam sterilisation
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Sterile sample
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Sterilisable
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Sterilising
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Sterility
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Sump space
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Surface
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There are three different types of surfaces:
Surface, geometric: An ideal surface the nominal shape of which is defined by the drawing and / or other technical documents. According to DIN 4760, sub-section 2.3.
Surface, actual: The approximate projection of the real surface of an element determined by measurement. According to DIN 4760, sub-section 2.2.
Surface, real: The surface which separates the object from the space surrounding it. According to DIN 4760, sub-section 2.1.
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Surface, geometric: An ideal surface the nominal shape of which is defined by the drawing and / or other technical documents. According to DIN 4760, sub-section 2.3.
Surface, actual: The approximate projection of the real surface of an element determined by measurement. According to DIN 4760, sub-section 2.2.
Surface, real: The surface which separates the object from the space surrounding it. According to DIN 4760, sub-section 2.1.
Surface colony count
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Surface treatment
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