ICS 23.080                          MED 20

Reaffirmed 2021

NATIONAL FOREWORD

This Indian Standard which is identical with ISO 21630 : 2007 ‘Pumps — Testing — Submersible mixers for wastewater and similar applications’ issued by the International Organization for Standardization (ISO) was adopted by the Bureau of Indian Standards on the recommendation of the Pumps Sectional Committee and approval of the Mechanical Engineering Division Council.

This International Standard prescribes acceptance test methods for submersible mixers for wastewater and other applications. It is intended for performance measurements relevant to submersible mixers bearing in mind the similarities to, and crucial differences from, submersible pumps. Hence head (pressure) and flow rate measurements are not included. The basic output performance parameter is the thrust. As continuous operation is common place, electric power consumption is important for the Life Cycle Cost, and is put forward as an important parameter.

ISO 21630 is a bilingual edition in English and French. As the Indian Standard is the National Implementation of ISO 21630 only the English language text will be considered while adopting it as an Indian Standard.

The text of the ISO Standard has been approved as suitable for publication as an Indian Standard without deviations. Certain conventions are, however, not identical to those used in Indian Standards. Attention is particularly drawn to the following:

a) Wherever the words ‘International Standard’ appear referring to this standard, they should be read as ‘Indian Standard’.

b) Comma (,) has been used as a decimal marker while in Indian Standards, the current practice is to use a point (.) as the decimal marker.

For the purpose of deciding whether a particular requirement of this standard is complied with, the final value, observed or calculated, expressing the result of a test or analysis shall be rounded off in accordance with IS 2 : 1960 ‘Rules for rounding off numerical values (revised)’. The number of significant places retained in the rounded off value should be the same as that of the specified value in this standard.