This International Standard specifies precision class pe mance tests for centrifugal, mixed flow and axial pumps. rfor- It defines the terms and quantities that are used and specifies general requirements for tests. It specifies ways of measuring the characteristic quantities of the precision class so as to ascertain the performance of the pump and thus provide a basis for comparison with the performance specified in the contract. The structural details of pumps and the mechanical properties of their co Standard. mponents lie outside the scope of this I nternational This International Standard does not specify constructional tolerances, which are purely contractual.