1、AWWA Standard SM Liquid Sodium Silicate Effective date: Sept. 1, 2014. First edition approved by AWWA Board of Directors Aug. 5, 1955. This edition approved June 8, 2014. Approved by American National Standards Institute April 17, 2014. ANSI/AWWA B404-14 (Revision of ANSI/AWWA B404-08) ii AWWA Stand
2、ard This document is an American Water Works Association (AWWA) standard. It is not a specification. AWWA standards describe minimum requirements and do not contain all of the engineering and administrative information normally contained in specifications. The AWWA standards usually contain options
3、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 defined. AWWA pub- lication of a standard does not constitute endorsement of any product or product type, nor does AWWA test, certify, or approve any product.
4、 The use of AWWA standards is entirely voluntary. This standard does not supersede or take precedence over or displace any applicable law, regulation, or codes of any governmental authority. AWWA standards are intended to represent a consensus of the water supply industry that the product described
5、will provide satisfactory service. When AWWA revises or withdraws this standard, an official notice of action will be placed on the first page of the Official Notice section of Journal - American Water Works Association. The action becomes effective on the first day of the month following the month
6、of Journal - American Water Works Association publication of the official notice. American National Standard An American National Standard implies a consensus of those substantially concerned with its scope and provisions. An American National Standard is intended as a guide to aid the manufacturer,
7、 the consumer, and the general public. The existence of an American National Standard does not in any respect preclude anyone, whether that person has ap - proved the standard or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not conforming to the standar
8、d. American National Standards are subject to periodic review, and users are cautioned to obtain the latest editions. Producers of goods made in conformity with an American National Standard are encour - aged to state on their own responsibility in advertising and promotional materials or on tags or
9、 labels that the goods are produced in conformity with particular American National Standards. Caution n oti Ce : The American National Standards Institute (ANSI) approval date on the front cover of this standard indicates completion of the ANSI approval process. This American National Standard may
10、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 years from the date of ANSI approval. Purchasers of American National Standards may receive current information on all standards by calling or writing t
11、he American National Standards Institute, 25 West 43rd Street, Fourth Floor, New York, NY 10036; (212) 642-4900, or emailing infoansi.org. ISBN-13, print: 978-1-62576-032-6 eISBN-13, electronic: 978-1-61300-293-3DOI: http:/dx.doi.org/10.12999/AWWA.B404.14 All rights reserved. No part of this publica
12、tion may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopy, recording, or any information or retrieval system, except in the form of brief excerpts or quotations for review purposes, without the written permission of the publisher. Copyright 2014
13、 by American Water Works Association Printed in USA hours of work by your fellow water professionals. Revenue from the sales of this AWWA material supports ongoing product development. Unauthorized distribution, either electronic or photocopied, is illegal and hinders AWWAs mission to support the wa
14、ter community. This AWWA content is the product of thousands of iii Committee Personnel The AWWA Standards Committee on Scale and Corrosion Control Chemicals, which reviewed and approved this standard, had the following personnel at the time of approval: Robert A. Ryder, Chair General Interest Membe
15、rs J.H. Bambei Jr., * Denver Water, Denver, Colo. (AWWA) M.S. McFadden, HDR Engineering Inc., Denver, Colo. (AWWA) N.E. McTigue, EE June 14, 1987; June 18, 1992; June 21, 1998; Jan. 19, 2003; and Jan. 27, 2008. This edition was approved on June 8, 2014. I.C. Acceptance. In May 1985, the US Environme
16、ntal Protection Agency (USEPA) entered into a cooperative agreement with a consortium led by NSF International (NSF) to develop voluntary third-party consensus standards and a certification program for direct and indirect drinking water additives. Other members of * American National Standards Insti
17、tute, 25 West 43rd Street, Fourth Floor, New York, NY 10036. The conversion from degrees Baum to specific gravity is outlined in Sec. 5.3.4 of the standard. viii the original consortium included the Water Research Foundation (formerly AwwaRF) and the Conference of State Health and Environmental Mana
18、gers (COSHEM). The American Water Works Association and the Association of State Drinking Water Administrators (ASDWA) joined later. In the United States, authority to regulate products for use in, or in contact with, drinking water rests with individual states.* Local agencies may choose to impose
19、requirements more stringent than those required by the state. To evaluate the health effects of products and drinking water additives from such products, state and local agencies may use various references, including a standard developed under the direc- tion of NSF, NSF/ANSI 60, Drinking Water Trea
20、tment ChemicalsHealth Effects. Various certification organizations may be involved in certifying products in accor- dance with NSF/ANSI 60. Individual states or local agencies have authority to accept or accredit certification organizations within their jurisdiction. Accreditation of certi- fication
21、 organizations may vary from jurisdiction to jurisdiction. Annex A, “Toxicology Review and Evaluation Procedures,” to NSF/ANSI 60 does not stipulate a maximum allowable level (MAL) of a contaminant for substances not regulated by a USEPA final maximum contaminant level (MCL). The MALs of an unspecif
22、ied list of “unregulated contaminants” are based on toxicity testing guidelines (noncarcinogens) and risk characterization methodology (carcinogens). Use of Annex A procedures may not always be identical, depending on the certifier. ANSI/AWWA B404 addresses additives requirements in Sec. 4.3.2 of th
23、e standard. The transfer of contaminants from chemicals to processed water or to residual solids is becoming a problem of great concern. The language in Sec. 4.3.2 is a recommenda- tion, only, for direct additives used in the treatment of potable water to be certified by an accredited certification
24、organization in accordance with NSF/ANSI 60, Drinking Water Treatment ChemicalsHealth Effects. However, users of the standard may opt to make this certification a requirement for the product. Users of this standard should also consult the appropriate state or local agency having jurisdiction in orde
25、r to 1. Determine additives requirements, including applicable standards. 2. Determine the status of certifications by parties offering to certify products for contact with, or treatment of, drinking water. 3. Determine current information on product certification. * Persons outside the United State
26、s should contact the appropriate authority having jurisdiction. NSF International, 789 N. Dixboro Rd., Ann Arbor, MI 48105. American National Standards Institute, 25 West 43rd Street, Fourth Floor, New York, NY 10036. ix II. Special Issues. II.A. Discussion. Liquid sodium silicate is generally shipp
27、ed in metal drums, tank trucks, or railroad tank cars. Most grades are fluid enough at room temperature and above to be purged easily. These liquids should be stored in closed, vented tanks. Storage tanks should have provisions for keeping the silicate from freezing. Sodium silicates are normally ad
28、ded to water by means of a chemical feed pump. Diaphragm, peristaltic, progressive cavity, gear, and piston pumps are satisfactory, but piston or gear pumps should have lantern-ring water glands around the pistons. For some uses, such as very low concentrations for boiler feed, hot water with elevat
29、ed magnesium, and some industrial uses to minimize scale formation, the silicate solu- tions can be diluted with freshwater before use; this is especially advisable if the silicate is fed into a brine. Silica is found to some extent in all natural waters and is believed to be ecologically harmless.
30、The addition of sodium silicate tends to slightly increase the pH and alkalin- ity of water and may increase turbidity in concentrations above 50 mg/L. II.B. Safety. Sodium silicate solutions are moderately to strongly alkaline. They are not explosive or flammable, and corrosion-control silica produ
31、cts are not classified as hazardous. Some of the other more alkaline solutions are considered hazardous in US Department of Transportation (DOT) shipping regulations for sodium silicate. The principal danger of silicate solutions involves contact with the eyes. Protective goggles and/or face shields
32、 should be worn when handling these products. If silicate is splashed into the eyes, flush immediately for 15 minutes and seek medical attention. If splashed on the skin, sodium silicate solution should be washed off quickly with waterpreferably warm water. If allowed to remain in contact with the s
33、kin, irritation may result. Dried deposits of the liquid should be treated with care, because they can cause skin cuts similar to those inflicted by broken glass. Such cuts should be washed with water and given appropriate medical attention to prevent infection. For additional safety information, re
34、fer to safety data sheets (SDSs) available from the supplier or manufacturer. 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 being considered. III.A. Purc
35、haser Options and Alternatives. The following information should be provided by the purchaser: 1. Standard usedthat is, ANSI/AWWA B404, Liquid Sodium Silicate, of latest revision. x 2. Quantity required. 3. Whether the recommended compliance with NSF/ANSI 60, Drinking Water Treatment ChemicalsHealth
36、 Effects, is required. 4. Details of other federal, state or provincial, and local requirements (Section 4). 5. Specific gravity required (Sec. 4.1.3). 6. SiO 2 :Na 2 O ratio required (Sec. 4.2.2). 7. Whether the purchaser will reject product from containers or packaging with missing or damaged seal
37、s. The purchaser may reject product from bulk containers or packages with missing or damaged seals unless the purchasers tests of representative samples, conducted in accordance with Sec. 5.2 through Sec. 5.5, demonstrate that the product meets the standard. Failure to meet the standard or the absen
38、ce of, or irregu- larities in, seals may be sufficient cause to reject the shipment. 8. Form of shipment, bulk or package, type, and size (Sec. 6.2). 9. Whether alternative security measures have been adopted to replace or aug- ment the security measures set out in Sec. 6.2.4 and 6.2.5. 10. Affidavi
39、t of compliance, or certified analysis, if required (Sec. 6.3). III.B. Modification to Standard. Any modification of the provisions, definitions, or terminology in this standard must be provided by the purchaser. I V. Major Revisions. Major revisions made to the standard in this edition include the
40、following: Inclusion of the use of this material for wastewater and reclaimed water as well as definitions of these terms (Sections 1 and 3). V. Comments. If you have any comments or questions about this standard, please call AWWA Engineering and Technical Services at 303.794.7711, FAX at 303.795.7603, write to the department at 6666 West Quincy Avenue, Denver, CO 80235-3098, or email at standardsawwa.org.
