Quality assurance, inspection and Performance certification
This Chapter details the requirements for the inspection of the base materials and components used in the manufacture of fans.
Knowledge of the particular Standards to which they are produced is particularly important especially at a time when national standards are being replaced by European standards.
Apart from aluminium alloys, where relevant grades are well defined, many non-ferrous metals and non-metal materials are purchased against trade names. It then becomes important to assess the quality reputation of the supplier and to determine whether he possesses a Quality Assessment such as ISO 9001.
This Chapter also describes the various inspection functions and the tests possible to confirm functionality. It defines what documentation the purchaser may expect to receive with the fan and also what additional information he may request if he wishes to carry out his own inspection. Guidelines are given for purchaser quality requirements.
When fans are “designed to order” and have to meet the purchaser’s specification, the whole question of quality becomes of major importance. In these instances it is recommended that the quality plan is produced and agreed before the signing of any contract. Non-compliance procedures should be included and tolerances on performance, dimensions, manufacturing defects etc., should all be defined.
It should be especially recognised that a balance has to be maintained between the customer’s aspirations and the price he is prepared to pay. The extent of control that is required ultimately depends upon the confidence which the customer has in a particular supplier, the trust which he is prepared to give, any legal requirements which may exist and any requirements laid down by insurance companies.
The fan industry has a claim to being “mature”. Its products have been around for up to 150 years. During this time much expertise has been built up by the long surviving companies. However, over the last 30 years, we have witnessed major upheaval and old established companies with excellent products have succumbed to the machinations of administrators without the same level of financial expertise. Small companies have been formed to fill the gap, but whilst their prices may be attractive, this is often because they do not have the necessary supporting structure to validate the design of their products.
Inspection of all components should be carried out by the manufacturer as a matter of course. The degree of inspection will be dependant upon the criticality of the component, its nature and its function. It may also be dependant on the batch size and whether “sampling” is appropriate. Mass-produced parts do not normally require the same degree of inspection as a small number of specially made parts. With batch production it may be sufficient to check the “first off” to ascertain that production has been correctly set up and then sample occasionally to check adherence.
The basic fan assembly stage having been completed, a final dimensional check should be carried out. Components not having the necessary fit or clearance should be readily apparent.
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