SANS 10298-2009 Indirect small to medium-sized gas chlorination systems for the disinfection of water《水消毒用间接小于中型的气体氯化系统》.pdf

1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA

2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any

3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 978-0-626-22842-2 SANS 10298:2009Edition 1.2SOUTH AFRICAN NATIONAL STANDARD Indirect small to medium-sized gas chlorination systems for the disinfec

4、tion of water Published by SABS Standards Division 1 Dr Lategan Road Groenkloof Private Bag X191 Pretoria 0001Tel: +27 12 428 7911 Fax: +27 12 344 1568 www.sabs.co.za SABS SANS 10298:2009 Edition 1.2 Table of changes Change No. Date Scope Amdt 1 2005 Amended to change the designation of SABS standar

5、ds to SANS standards and to update the referenced standards. Amdt 2 2009 Amended to update a referenced standard and to move reference to legislation to the foreword. Foreword This South African standard was approved by National Committee SABS TC 138, Water and sanitation Equipment and systems, in a

6、ccordance with procedures of the SABS Standards Division, in compliance with annex 3 of the WTO/TBT agreement. This document was published in September 2009. This document supersedes SANS 10298:2005 (edition 1.1). A vertical line in the margin shows where the text has been technically modified by am

7、endment No. 2. Annex A is for information only. A reference is made in 5.1.1.1, 6.2.5 and in the NOTE to 6.2.5 to “relevant safety legislation”. In South Africa this means the Occupational Health and Safety Act, 1993 (Act No. 85 of 1993). A reference is made in 5.1.1.1 to “relevant legislation”. In

8、South Africa this means the Mines and Works Act, 1956 (Act No. 27 of 1956). SANS 10298:2009 Edition 1.2 1 Contents Page Foreword 1 Scope . 3 2 Normative references . 3 3 Definitions 3 4 Chlorination equipment and ancillaries 6 4.1 System type description 6 4.2 Classification of chlorination systems

9、by size . 6 4.3 Materials 7 4.4 Containers . 10 5 Layout and installation . 12 5.1 Components 12 5.2 Jointing, gaskets and sealing materials 13 5.3 The design of chlorine rooms 14 5.4 Characteristics of chlorine in piping systems 14 5.5 Preparation of systems for use . 15 6 Operational safety 16 6.1

10、 Responsibilities in the event of an emergency 16 6.2 General safety requirements . 16 6.3 Emergency action plan 17 6.4 Safety and warning signs 17 6.5 Personal protective equipment . 17 6.6 Handling of containers 18 6.7 Medical management 19 6.8 Information for physicians . 21 7 Maintenance . 22 7.

11、1 General 22 7.2 Leaks . 23 7.3 Equipment maintenance . 23 7.4 Use of arc-producing and flame-producing apparatus 24 8 Training 24 Figure 1-7 25-30 Annex A Additional information 31 SANS 10298:2009 Edition 1.2 2 This page is intentionally left blank SANS 10298:2009 Edition 1.2 3 Indirect small to me

12、dium-sized gas chlorination systems for the disinfection of water 1 Scope This standard gives recommendations in respect of the selection of equipment, installation practice and the maintenance of small to medium-sized chlorine gas installations. It gives recommendations for vacuum type systems with

13、 up to six cylinders or a single “ton“ container of nominal capacity 1 000 kg. It lays down procedures to be followed to minimize risks to the safety of persons and the environment in terms of exposure to chlorine. General guidelines regarding medical treatment of persons exposed to chlorine are inc

14、luded. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this standard. All standards are subject to revision and, since any reference to a standard is deemed to be a reference to the latest edition of that standard, par

15、ties to agreements based on this standard are encouraged to take steps to ensure the use of the most recent editions of the standards indicated below. Information on currently valid national and international standards can be obtained from the SABS Standards Division. SANS 9956-3/ISO 9956-3 (SABS IS

16、O 9956-3), Specification and approval of welding procedures for metallic materials Part 3: Welding procedure tests for the arc welding of steels. Amdt 1; Amdt 2 SANS 10019, Transportable containers for compressed, dissolved and liquefied gases Basic design, manufacture, use and maintenance. Amdt 1 S

17、ANS 10140-3, Identification colour markings Part 3: Contents of pipelines. SANS 15614-1/ISO 15614, Specification and qualification of welding procedures for metallic materials Welding procedure test Part 1: Arc and gas welding of steels and arc welding of nickel and nickel alloys. Amdt 2 3 Definitio

18、ns For the purposes of this standard, the following definitions apply: 3.1 approved inspection authority organization that is approved by the regulatory authority SANS 10298:2009 Edition 1.2 4 3.2 bronchospasm spasmodic constriction of the bronchial tubes 3.3 chlorination use of chlorine to disinfec

19、t water 3.4 chlorinator composite device that regulates the flow of gaseous chlorine into a water system 3.5 chlorine detector sensing device that detects the presence of chlorine gas in the atmosphere, activates an alarm or shuts off the system, and starts a safety procedure 3.6 chlorine filter dev

20、ice installed in a chlorination system to remove particulate matter 3.7 chlorine gas; gaseous chlorine element chlorine in the gaseous state 3.8 chlorine solution solution of chlorine in water 3.9 container container manufactured in accordance with SANS 10019 that is used for the transportation or s

21、torage (or both) of chlorine 3.10 corticosteroid any of the hormones of the adrenal cortex or any synthetic substitute 3.11 cylinder portable chlorine container of maximum (filled) mass 70 kg that is used only in the vertical position and that supplies only gaseous chlorine 3.12 dermatitis inflamati

22、on of the skin 3.13 diffuser device that disperses chlorine gas before exposure of the gas to water in order to maximize its absorption 3.14 dosing unit device that indicates chlorine flow rate SANS 10298:2009 Edition 1.2 5 3.15 dry chlorine liquid or gaseous chlorine product that contains no more t

23、han 150 g of water per gram of product NOTE The dry compound used in swimming pool sanitation is not dry chlorine. 3.16 emesis vomiting 3.17 evaporator vaporizer device in which liquid chlorine is converted to gaseous chlorine by the addition of heat and that is mainly used in high-rate chlorination

24、 systems 3.18 flow regulator device that controls the flow of chlorine to a water system at a constant rate 3.19 injector vacuum injector that allows chlorine gas to be drawn into a water solution under operating conditions only 3.20 lacrimation formation of tears in the eyes 3.21 liquid chlorine ca

25、tchpot device that is installed in chlorine supply piping from chlorine containers, upstream of all regulating and control devices, to prevent liquid chlorine carry-over 3.22 moist chlorine wet chlorine chlorine product, liquid or gaseous, that contains more than 150 g of water per gram of product 3

26、.23 pharynx musculomembranous cavity located behind the nasal cavities, mouth and larynx 3.24 portable tank portable chlorine container of maximum (filled) mass 1 000 kg that is used only in the horizontal position and that can supply both liquid or gaseous chlorine 3.25 pulmonary relating to the lu

27、ngs 3.26 rhinorrhea profuse watery nasal discharge SANS 10298:2009 Edition 1.2 6 3.27 substernal situated beneath the breastbone 3.28 syncope brief loss of consciousness; a faint 3.29 vacuum pressure regulator device that reduces unregulated chlorine gas pressure from a chlorine gas supply system to

28、 a constant supply under vacuum 4 Chlorination equipment and ancillaries NOTE Typical chlorine installations are indicated in figures 1 to 5. 4.1 System type description 4.1.1 Vacuum systems A vacuum system is one in which an injector unit is used to create a negative pressure such that chlorine is

29、only drawn into and mixed with a water supply when the water is flowing, i.e. being pumped. In the event of a fault condition the vacuum is interrupted and the chlorine feed stops operating. Typical components of a vacuum chlorination system are a) chlorine supply, b) dosing unit and vacuum regulato

30、r (chlorinator), c) injector, d) pumps, piping, filters and gauges, and e) adjustable flow meters. 4.1.2 Pressure systems A pressure system feeds pressurized gaseous chlorine direct into the water supply. The use of a pressure system is also known as direct chlorination. This involves great risk as

31、the built-in safety aspect of a vacuum system is not present in this type of system. Direct injection systems therefore require careful design and operation. 4.2 Classification of chlorination systems by size 4.2.1 Classification Chlorination systems can be divided into two size-related categories:

32、small systems (up to 5 kg), medium systems (5 to 10 kg), and large systems (over 10 kg). SANS 10298:2009 Edition 1.2 7 Table 1 Format of chlorine installations 1 2 3 4 Chlorine installation type Discerning feature Gas capacity per container at 20 C Comment Single-cylinder installation (see figure 1)

33、 Cylinder-mounted chlorinator Up to 800 g/h Limited supply Single-cylinder installation(see figure 2) Wall-mounted chlorinator Up to 800 g/h Limited supply Multiple-cylinder installation (see figure 3) Cylinder-mounted auto changeover Up to 800 g/h per cylinder Continuous supply Multiple-cylinder in

34、stallation (see figure 4) Manifold Up to 800 g/h per cylinder Continuous supply Single portable container installation Gas supply 6,8 kg/h Limited supply Multiple portable container (see figure 5) Gas supply manifold 6,8 kg/h per tank Continuous supply Portable container installation, single or mult

35、iple container(s) Liquid supply using evaporator Above 40 kg/h Continuous supply 4.2.2 Small to medium systems In order to minimize the dangers (such as the risk of exposure of the eyes, skin and mucous membranes to chlorine) inherent in small to medium chlorination systems, the following components

36、 or fittings (or a combination of them) should be used, if practicable: a) wall-mounted manifold chlorinator(s); b) direct-mounted cylinder(s) or portable tank(s); c) heated liquid filter(s), and catchpots; and d) isolating safety valve(s). 4.2.3 Large systems Large systems usually source chlorine i

37、n liquid form. In these layouts the continuous supply of chlorine is critical. However, these systems are not covered by this standard. 4.3 Materials All the component parts of a chlorination system, such as membranes, springs, valve seats and casings, that are in direct contact with chlorine gas (o

38、r liquid), shall be manufactured from high-quality fully resistant materials as indicated in table 2. All materials that are used, including for non-metallic parts for joints, seals, diaphragms, hoses, etc., shall be resistant to the action of chlorine, its impurities and other substances that are p

39、resent under the relevant operating conditions of temperature, pressure and corrosion. SANS 10298:2009 Edition 1.2 8 Table 2 Materials for use with chlorine 1 2 3 4 Liquid Dry chlorine gas Wet chlorine gas Room temp. Max. temp. Room temp. Material Chlorine C C C Atlac1) 2)X3)S3)104 S (up to 140 C) B

40、rass (60-90 percent copper) S S 180 X Bronze (aluminium-silicon grade without Zn) S S 180 Corrosion rate 0,25 mm/year Cast iron S S 100 X Copper S 100 Duracor 6000 (FRP)2)X S 100 S (up to 82 C) Glass X S 204 S UNS No 10276, Hastelloy C1) 2)S S 510 X UNS No 6600, Inconel1) 2)S S 540 X PVDF, e.g. Kyna

41、r2)X S 100 X Lead (gaskets only) S S 100 X UNS No 4400, Monel1) 2)S S 320 X UNS No 2201, nickel1)S S 250 X Platinum S S 250 S Polyethylene (high-density) X X X Polyethylene (low-density) X X X PTFE, e.g. Teflon2)S S 250 S PVC-u X S X Rubber (hard-cured) X S 150 S PVC, e.g. Saran2)X S 80 S Silver S S

42、 425 Steel (suitable grades) S S 100 X Stainless steel (suitable grades) S S 180 X Tantalum S S 150 S (up to 150 C) Titanium X X S 1) The above table only takes corrosion resistance properties of the materials into account. The effects of any fabrication and welding procedures used should also be co

43、nsidered. 2) The trade names referred to are registered and commonly used. However, this information is given only for the convenience of users of this standard. This in no way constitutes endorsement of the products referred to. Equivalent products may be used if they can be shown to produce the sa

44、me results. 3) The letter S indicates that the material might be usable, but does not necessarily indicate complete freedom from corrosion. X indicates that the material is unsuitable. When selecting a material for a particular application, care should be taken to comply with statutory regulations.

45、It should also be borne in mind that some metals may not be used at pressures above atmospheric. SANS 10298:2009 Edition 1.2 9 NOTES 1 As chlorine is an extremely dangerous substance it is advisable that each individual chlorine application be studied in detail and that specialists on chlorine be co

46、nsulted before the selection of materials. 2 The user shall ensure that material thicknesses comply with the requirements of this standard and shall take into account pressure and temperature conditions together with all safety factors. 3 Check the grade to be used with the material supplier. 4.3.1

47、Selection of materials for use with moist chlorine CAUTION Moist chlorine is extremely corrosive to all the common construction metals and its use in conjunction with such metals shall be avoided. At low pressures hard rubber, unplasticized polyvinylchloride, glass-fibre reinforced polyester, poly-v

48、inylidene chloride or polyvinylidene fluoride can be used for either the components of the system or for the lining of the parts. Fully halogenated fluorocarbon resins of a suitably chemical resistant grade may be used, depending on the specific application. All of these materials should be selected

49、 with great care. For higher pressures, common metals shall be used in combination with resistant lining materials for strength. 4.3.2 Special applications for materials in use with chlorine 4.3.2.1 Titanium may be used with moist chlorine but shall not be used with dry chlorine under any circumstances as it burns spontaneously on contact. Tantalum is inert to moist and dry chlorine at temperatures of up to 149 C. High-alloyed nickel steels and Monel are widely used. Platinum and silver have special applications. In general, operations that involve mo