ISO 9906:2012 pdf free download.Rotodynamic pumps — Hydraulic performance acceptance tests — Grades 1, 2 and 3.
ISO 9906:2012 specifies hydraulic performance tests for customers’ acceptance of rotodynamic pumps (centrifugal, mixed flow and axial pumps). It is intended to be used for pump acceptance testing at pump test facilities, such as manufacturers’ pump test facilities or laboratories. ISO 9906:2012 can be applied to pumps of any size and to any pumped liquids which behave as clean, cold water.
ISO 9906:2012 applies either to a pump itself without any fittings or to a combination of a pump associated with all or part of its upstream and/or downstream fittings.
The tests in this International Standard are intended to ascertain the performance of the pump and to compare this with the manufacturer s guarantee.
The nominated guarantee for any quantity is deemed to have been met if, where tested according to this International Standard, the measured performance falls within the tolerance specified for the particular quantity (see 4.4).
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.
amber 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 manufacturers 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 6,
1)the minimum pump efficiency, G, or the maximum pump input power, PG, or
2) in the case of a combined pump and motor unit, the minimum combined efficiency, ngrG, 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 requirement 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.