AWWA D106-2016 Sacrificial Anode Cathodic Protection Systems for the Interior Submerged Surfaces of Steel Water Storage Tanks.pdf

1、AWWA Standard SM Sacrificial Anode Cathodic Protection Systems for the Interior Submerged Surfaces of Steel Water Storage Tanks Effective date: June 1, 2016. First edition approved by AWWA Board of Directors June 20, 2010. This edition approved Jan. 16, 2016. Approved by American National Standards

2、Institute Oct. 30, 2015. ANSI/AWWA D106-16 (Revision of ANSI/AWWA D106-10) Copyright 2016 American Water Works Association. All Rights Reserved. ii AWWA Standard This document is an American Water Works Association (AWWA) standard. It is not a specification. AWWA standards describe minimum requireme

3、nts and do not contain all of the engineering and administrative information normally contained in specifications. The AWWA standards usually contain options that must be evaluated by the user of the standard. Until each optional feature is specified by the user, the product or service is not fully

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5、ulation, or code of any governmental authority. AWWA standards are intended to represent a consensus of the water supply industry that the product described will provide satisfactory service. When AWWA revises or withdraws this standard, an official notice of action will be placed on the first page

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10、nstitute (ANSI) approval date on the front cover of this standard indicates completion of the ANSI approval process. This American National Standard may be revised or withdrawn at any time. ANSI procedures require that action be taken to reaffirm, revise, or withdraw this standard no later than five

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12、nt: 978-1-62576-151-4 eISBN-13, electronic: 978-1-61300-374-9DOI: http:/dx.doi.org/10.12999/AWWA.D106.16 All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopy, recording, or any information or retr

13、ieval system, except in the form of brief excerpts or quotations for review purposes, without the written permission of the publisher. Copyright 2016 by American Water Works Association Printed in USA hours of work by your fellow water professionals. Revenue from the sales of this AWWA material supp

14、orts ongoing product development. Unauthorized distribution, either electronic or photocopied, is illegal and hinders AWWAs mission to support the water community. This AWWA content is the product of thousands of Copyright 2016 American Water Works Association. All Rights Reserved. iii Committee Per

15、sonnel The AWWA Cathodic Protection Task Force, which developed this standard, had the following personnel at the time: David H. Kroon, Chair W.J. Czaska, CB however, the combination of coatings and cathodic protection is normally more economical and effective than using coatings or cathodic protect

16、ion alone. II.B. Cathodic Protection. The two major components of a sacrificial anode cathodic protection system are the anodes and the test box for monitoring and current control. In lieu of a test box, the manufacturer may provide an alternative means for monitoring and current control. The range

17、of sacrificial anode output current capacity required for a specific tank is determined by estimating the area of submerged bare steel to be protected when the interior tank coating is new and when the interior coating has deteriorated to the point where recoating is necessary. In potable water, cur

18、rent density requirements can range from 0.5 to 5.0 mA/ft 2(5.4 to 53.8 mA/m 2 ) of bare steel surface. Applications involving turbulence, high temperature, or both may require higher current densities. For newly coated tanks, the total current requirement may be as little as 1 percent of the curren

19、t required to protect an uncoated interior tank surface. As a rule, sacrificial anode systems for newly coated tanks should have sufficient current capacity to protect the anticipated bare submerged surface area before coating repairs or replacement. A sacrificial anode cathodic protection system sh

20、ould include a test box or other means for measuring tank-to-water potentials and adjusting the current output of the sacrificial anodes. One or more long-life reference electrodes should be included in the system to monitor the protection levels on the submerged steel surfaces. The reference electr

21、ode is used to monitor the tank-to-water potential, free of IR drop error. IR drop must be eliminated or minimized to accurately determine the potential between the tank surface and the reference electrode submerged in the tank. The test box allows for the anode current to be instantaneously interru

22、pted, providing an IR drop-free poten- tial that closely approximates the polarized potential of the tank. III. Use of This Standard. It is the responsibility of the user of an AWWA standard to determine that the products described in that standard are suitable for use in the particular application

23、being considered. Contractual responsibilities for items such as design, material, fabrication, con- struction, inspection, testing, and operation have been removed from the standard and must be addressed in the contract documents. Copyright 2016 American Water Works Association. All Rights Reserved.