AS ISO 9906:2018 pdf free.Australian Standard  Rotodynamic pumps一Hydraulic performance acceptance tests一 Grades 1, 2 and 3.
4 Pump measurements and acceptance criteria
4.1 General
The specified and contractually agreed upon rated point (duty point), hereinafter “the guarantee point”, shall be evaluated against one acceptance grade and its corresponding tolerance. For a pump performance test, this guarantee point shall always specify the guaranteed flow, QG0 and guaranteed head, HG, and may, optionally, specify guaranteed efficiency, guaranteed shaft power or guaranteed net positive suction head required (NPSHR). Where applicable, these optional guarantee parameters need to be specified for those tests, see respective tests in 4.4.3 and 5.
The acceptance grade tolerance applies to the guarantee point only. Other specified duty points, including their tolerances, shall be by separate agreement between the manufacturer and purchaser. If other specified duty points are agreed upon, but no tolerance is given for these points, the default acceptance level for these points shall be grade 3.
A guarantee point may be detailed in a written contract, a customer-specific pump performance curve or similar written and project specific documentation.
If not otherwise agreed upon between the manufacturer and the purchaser, the following shall apply.
a) The acceptance grade shall be in accordance with the grades given in Table 8.
b) Tests shall be carried out on the test stand of the manufacturer’s works with clean, cold water using the methods and test arrangements specified in this International Standard.
c) The pump performance shall be guaranteed between the pump’s inlet connection and outlet connection.
d) Pipe and fittings (bends, reducers and valves) outside of the pump are not a part of the guarantee.
The combination of manufacturing and measurement tolerances in practice necessitates the usage of tolerances on tested values. The tolerances given in Table 8 take into account both manufacturing and measurement tolerances.
The performance of a pump varies substantially with the nature of the liquid being pumped. Although it is not possible to give general rules whereby performance with clean, cold water can be used to predict performance with other liquids, it is desirable for the parties to agree on empirical rules to suit the particular circumstances. For further information, see ISO/TR 17766.
If a number of identical pumps are being purchased, the number of pumps to be tested shall be agreed between the purchaser and manufacturer.
Both the purchaser and manufacturer shall be entitled to witness the testing. If tests are not carried out at the manufacturer’s test stand, opportunity shall be allowed for verification of the pump installation and instrumentation adjustments by both parties.
4.2 Guarantees
The manufacturer guarantees that, for the guarantee point and at the rated speed (or in some cases frequency and voltage), the measured pump curve touches, or passes through a tolerance surrounding the guarantee point, as defined by the applicable acceptance grade (see Table 8 and Figures 2 and 3).
A guarantee point shall be defined by a guaranteed flow, QG. and a guaranteed head, HG.
In addition, one or more of the following quantities may be guaranteed at the specified conditions and at the rated speed:
a) as defined in 4.4.3 and Figures 4.5 and fi,
1) the minimum pump efficiency, q, or the maximum pump input power, PG, or
2) in the case of a combined pump and motor unit, the minimum combined efficiency, I1grG or the maximum pump motor unit input power, PgrG.
b) the maximum NPSHR at the guarantee flow.
The maximum power input may be guaranteed for the guarantee point or for a range of points along the pump curve. This, however, can require larger tolerances to be agreed upon between the purchaser and manufacturer.
4.3 Measurement uncertainty
4.3.1 General
Every measurement is inevitably subject to some uncertainty, even if the measuring procedures and the instruments used, as well as the methods of analysis, fully comply with good practice and with the requirements of this International Standard.
The guidance and procedures described in 4.3.2 and 4.3.3 are intended to provide general information to the user, as well as practical procedures allowing the user to estimate measurement uncertainty with reasonable confidence in applying the testing in conformity with this International Standard.
NOTE For comprehensive information on measurement uncertainty, see ISO/IEC Guide 99 and associated documents.AS ISO 9906 pdf download.