Incorrect Assembly Impossible

By making incorrect assembly impossible (for an example, see Section 9.1.3). 

Making Incorrect Assembly Impossible -choice of equipment, piping and fittings correctly equipment safety safe process structure... 

Making Incorrect Assembly Impossible Plants should be designed so that incorrect assembly is difficult or impossible. For example, compressor valves should be designed so that inlet and exit valves cannot be interchanged hose connections of different types or sizes should be used for compressed air and nitrogen. 

Incorrect assembly of plant made impossible by equipment design. 

Preventing incorrect assembly. Design equipment so that improper construction or reassembly is impossible or very difficult. 

How often has this been said by the designer after a piece of equipment has failed The designer is usually correct, but whenever possible we should use designs that are impossible (or difficult) to assemble incorrectly or that are unlikely to fail if assembled incorrectly. For example ... 

As discussed in Section 3.2.1, equipment should be designed so that it is difficult or impossible to assemble it incorrectly or so that the incoirect assembly is immediately apparent. 

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