Blind insert

It is used as a separator gasket on both sides of a blind inserted in high temperature ducts. 

Fig. 7. Suggested design and dimensions of a range of blind inserts.

The gap between laboratory wear testing and industrial appHcation trials is extremely difficult to bridge, since there is often Httie or no control over testing in the industrial environment. Despite these limitations, several examples of industrial successes involving ion implanted tools have been reported and blind tests of nitrogen-implanted machine tools have been performed, including tool taps, dies, punches, and TiN coated WC cutting inserts (106). 

Hard gelatin capsules are uniquely suitable for blinded clinical tests and are widely used in preliminary drug studies. Bioequivalence studies of tablet formulations may be conveniently blinded by inserting tablets into opaque capsules, often along with an inert filler powder. Even capsule products may be disguised by inserting them into larger capsules. 

Blind samples are types of sample which are inserted into the analytical batch without the knowledge of the analyst - the analyst may be aware that blind samples are present but not know which they are. Blind samples may be sent by the customer as a check on the laboratory or by laboratory management as a check on a particular system. Results from blind samples are treated in the same way as repeat samples - the customer or laboratory manager examines the sets of results to determine whether the level of variation, between repeat measurements on the blind sample or between the observed results and an expected value, is acceptable, as described in Section 5.4.3. 

A 67-year-old man with prostate cancer and an unsuspected pituitary macroadenoma developed a severe frontal headache, nausea and vomiting, and blindness within 12 hours of insertion of a goserelin implant (11). 

With a newly installed precautionary blind in the overflow line, the hidden blind in the vent line, and no additional overpressure devices, the tank was destined to fail. As liquid was pumped into the vessel the inerts had no place to go and the tank was pressurized to destruction. To the best of everyone s knowledge and the evidence, this hard-to-detect blind may have been inserted over a year prior to the incident for a previous internal inspection of the acid tank. Obviously the mechanic(s) who removed the other blinds a year or so before and on this occasion did not notice this one. 

The G-BASE project collects samples in random number order (Plant, 1973), as this helps identify any correctable systematic errors introduced during sample preparation and analysis, processes in which the samples are handled in numeric order. For every block of one hundred numbers, five numbers are reserved for control samples so when they are submitted within a batch of samples they are blind to the analyst. The control samples inserted are one duplicate sample, two replicate samples, two blanks, and two secondary reference materials (SRM) used to monitor accuracy and precision as well as to level data between different field campaigns (see Johnson et al, 2008). Along with the original sample ofthe duplicate pair, this means 8% of samples submitted are control samples, a point not to be overlooked in setting the budget for analyses. 

These blind control samples are in addition to any primary reference materials (PRM) that the laboratory may also analyse. For the G-BASE project, the BGS laboratories usually insert a PRM at the beginning and end of each batch of 500 samples. As G-BASE generally collects and analyses 2000—3000 samples each field campaign 8% of the samples is more than adequate to carry out quality control procedures. However, if sample numbers are <500, then it is recommended that the number of duplicates and replicates per hundred samples should be doubled. 

A key to quality control of environmental analyses is the insertion of blind (hidden) control samples (duplicates, replicates and reference materials) among the routinely collected samples. The control samples need to be allocated sample numbers that make them indistinguishable from the normal samples when submitted for analysis. This can be achieved by the use of sample number list sheets such as that illustrated in Fig. 5.3. 

Established Phillips corporate safety procedures and standard industry practice require backup protection in the form of a double valve or blind flange insert whenever a process... 

Insert the end of the rod that extends through the pipe cap, into the center fitting on the inside of the bottom blind flange. 

Insert the blind flange with attached negative electrode assembly into place. Be sure to align the holes in the blind flange with those in the... 

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