ISO INTERNATIONAL STANDARD 9912-4 First edition 2018-08 Agricultural irrigation equipment - Filters for microirrigation - Part 4: Granulated media filters Matériel agricole d'irrigation - Filtres pour micro-irrigation - Reference number IS09912-4:2018(E) [so International Organization for Standardization andards and Technology 9972181 @IS02018 IS0 9912-4:2018(E) COPYRIGHTPROTECTEDDOCUMENT @IS02018 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting below or Iso's member body in the country of the requester. ISO copyright office CP401·Ch.deBlandonnet8 CH-1214 Vernier, Geneva Phone:+4122 749 0111 Fax: +41 22 749 09 47 Email: [email protected] Website: www.iso.org Published in Switzerland ganizationfor Standardization icensee-Shenzhen Institute of Standards andecISogf1&- All rights reserved rious National Standards Bodies IS0 9912-4:2018(E) Contents Page Foreword ..iv 1 Scope .1 2 Normative references 3 Terms and definitions 4 Design and construction requirements. .2 4.1 General 2 4.2 Inlet and expansion space chamber 4.3 Media chamber. .5 4.4 Collection (underdrain) and back flushing unit 4.5 Prefiltration element. .5 4.6 Back flushing control. ..6 4.6.1 Mandatory requirements .6 4.6.2 Optional features .6 5 Resistance of the filter to internal hydrostatic pressure .6 5.1 General .6 5.2 Preparation .7 5.3 Static pressure test. ..7 5.4 Cyclic pressure test .7 5.5 Collection (underdrain) and back flushing unit resistance to buckling or tearing 6 Clean pressure drop test ..9 6.1 General, .9 6.2 Flow rates and test sequence 6.3 Filtermedia .9 6.4 Prescreening 6.5 Inlet and outlet pressures. ..9 6.6 Testduration .9 6.7 Report. ..10 7 Back flushing tests. .10 7.1 Back flushing parameters .10 7.2 Media escape test. ..10 8 Automatic back flushing and controller .11 8.1 Back flushing initiation. .11 8.2 Flushing control mechanism test .11 8.2.1 Mechanism activated by pressure drop .11 8.2.2 Mechanism activated by duration of operation ..11 8.2.3 Mechanism activated by volume of filtered water ..11 8.2.4 Mechanism activated by another physical quantity ..12 8.3 Operation of the protective device. .12 9 Information to be supplied by the manufacturer ..12 9.1 General ..12 9.2 Filterdata. ..13 9.3 Back flushing controller. ..13 Annex A (informative) Types of irrigation media filters .14 Annex B (informative) Granulated media .15 ntemaionalganzationAll rights reserved iii Not for Resale, 2018/11/26 07:55:47