ImageVerifierCode 换一换
格式:PDF , 页数:3 ,大小:61.69KB ,
资源ID:1016759      下载积分:10000 积分
快捷下载
登录下载
邮箱/手机:
温馨提示:
如需开发票,请勿充值!快捷下载时,用户名和密码都是您填写的邮箱或者手机号,方便查询和重复下载(系统自动生成)。
如填写123,账号就是123,密码也是123。
特别说明:
请自助下载,系统不会自动发送文件的哦; 如果您已付费,想二次下载,请登录后访问:我的下载记录
支付方式: 支付宝扫码支付 微信扫码支付   
注意:如需开发票,请勿充值!
验证码:   换一换

加入VIP,免费下载
 

温馨提示:由于个人手机设置不同,如果发现不能下载,请复制以下地址【http://www.mydoc123.com/d-1016759.html】到电脑端继续下载(重复下载不扣费)。

已注册用户请登录:
账号:
密码:
验证码:   换一换
  忘记密码?
三方登录: 微信登录  

下载须知

1: 本站所有资源如无特殊说明,都需要本地电脑安装OFFICE2007和PDF阅读器。
2: 试题试卷类文档,如果标题没有明确说明有答案则都视为没有答案,请知晓。
3: 文件的所有权益归上传用户所有。
4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
5. 本站仅提供交流平台,并不能对任何下载内容负责。
6. 下载文件中如有侵权或不适当内容,请与我们联系,我们立即纠正。
7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。

版权提示 | 免责声明

本文(PPI STATEMENT N-2013 Plastics Pipe Institute Position Statement on Barrier Properties of Plastic Pipe Used for Potable Water Service.pdf)为本站会员(explodesoak291)主动上传,麦多课文库仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对上载内容本身不做任何修改或编辑。 若此文所含内容侵犯了您的版权或隐私,请立即通知麦多课文库(发送邮件至master@mydoc123.com或直接QQ联系客服),我们立即给予删除!

PPI STATEMENT N-2013 Plastics Pipe Institute Position Statement on Barrier Properties of Plastic Pipe Used for Potable Water Service.pdf

1、 STATEMENT N Plastics Pipe Institute Position Statement on Barrier Properties of Plastic Pipe Used for Potable Water Service Issued July, 1984 Revised June 2002 Revised January 2013 INTRODUCTION Plastic pipe has been used with confidence in potable water systems for over 40 years and has been demons

2、trated to be safe and economical in this application. Over these many years of satisfactory use, the occurrence of permeation has been extremely rare. It has been observed only in situations where there was unusual and severe environmental contamination. In these instances, the question of permeatio

3、n of potable water piping systemswhich can affect all types of piping systemsneeds to be addressed. Permeation refers to the phenomenon by which chemical substances in surrounding soils can travel through the walls of buried pipe or of piping components such as gaskets. PROVEN ADVANTAGES Plastic pip

4、e has been shown to be an environmentally safe way to transport drinking water because plastics used in potable water pipe are inert in the normal environment. Bacteria or fungi do not affect them, and they do not react with acidic or basic soils. Plastic pipe does not rust or corrode. It is resilie

5、nt, resisting cracking or breaking, even in unstable soil conditions. In short, plastic pipe often works better, lasts longer and is more cost effective than the materials it replaces. The documented performance of plastic pipe has made it a preferred material. CONCERNS In potable water systems, one

6、 of the primary concerns is the maintenance of water qualitythe piping materials must protect the water from any possible external contaminants while also being neutral to water quality. All piping systems appear to have some slight potential for contamination from external reagents though permeatio

7、n of gaskets, permeation of pipe wall, and liquid exchange through all types of leaks. For example, metal and concrete piping are vulnerable to corrosion by inorganic acid and alkaline contaminants that could make the piping vulnerable to infiltration. Plastic piping is immune to this type of attack

8、. On the other hand, some organic solvents, if present in sufficient quantity and over a prolonged duration, could be absorbed by the pipe material and permeate in slight concentrations into the potable water. Fortunately, serious environmental contamination of soils are rare and are readily identif

9、iable. In soils heavily contaminated with hydrocarbon solvents, permeation also can occur through the elastomeric gasket joints, which are used extensively with a variety of different types of piping materials. Battelle Research Institute1tested piping systems under exaggerated conditions in soil he

10、avily saturated with contaminants that could permeate plastics, have indicated that permeation will occur rather quickly through elastomeric gasketed joints in a variety of different types of potable water piping. In a real life situation, of course, the degree of permeation, if any would depend upo

11、n the severity of soil contamination, the type of contaminant, the composition of the soil itself, the pipe size/wall thickness and the flow rate (and dilution) past the permeated materials. In support of the plastic piping industries growing need for more detailed information, The Plastics Pipe Ins

12、titute contracted with Indiana University Purdue University Indianapolis (IUPUI)to develop a report to assist the users titled “ASSESSMENT AND CALCULATION OF BTEX PERMEATION THROUGH HDPE WATER PIPE” which was published in the summer of 2012. Previous work from Ong et al2established diffusion coeffic

13、ients for several aromatic components of gasoline namely, benzene, toluene, ethylbenzene and xylenes (BTEX) - and permeation rates for those components through a 1-inch diameter (0.146” wall) Iron Pipe Size (IPS) HDPE water pipe in various laboratory conditions similar to the previous Battelle work.

14、 In contrast, the PPI supported work from the IUPUI researchers provides a step-by-step methodology for mathematically estimating the amounts of BTEX that permeates into a potable water HDPE pipeline under a wide variety of service conditions “and design variables including bulk concentration of BTE

15、X in soil, ground temperature, groundwater saturation, flow velocity, water stagnation, pipe thickness, and soil characteristics”. The example calculations provided in the IUPUI report “show that the presence of BTEX contamination in soil along an HDPE water pipe does not necessarily mean that the d

16、rinking water in the pipe will exceed regulatory limits”. This PPI supported research is the most detailed to date and “may assist engineers and others when they need to make an engineering decision for water pipe material selection”. This PPI supported research is provided on the PPI website free o

17、f charge for the benefit of all at http:/plasticpipe.org/pdf/permeation-report.pdf. In addition to the IUPUI report, PPI had commented on the previous work by Ong as shown at http:/www.plasticpipe.org/pdf/ppi-comment-permeation-hydrocarbons.pdf RECOMMENDATIONS In any situation where heavy soil conta

18、mination occurs, no pipe system can be considered resistant to permeation. For these reasons, the contaminating source must be controlled or the pipe route avoided altogether, regardless of the pipe material being used. In areas of known or suspected contamination, the design of the distribution sys

19、tem should be based on a careful analysis of the situation. Situations calling for scrutiny on a case-by-case basis would include (but not be limited to): Tank farms or industrial sites containing chemical or petroleum storage tanks and pipelines where a malfunction or leak would contaminate the sur

20、rounding soil. Storage ponds or land disposal sites for industrial process water or wastewater containing toxic chemicals Solid waste disposal sites An area that has been known to be contaminated by the long-term presence of toxic chemical substances. Appropriate technical data and individual manufa

21、cturers recommendations should be consulted on the overall design of a pipe system for these situations. OUTLOOK As long as proper consideration is given to these potentially serious contamination sources in planning and installing potable water piping systems, the likelihood of a permeation problem

22、 causing a public health hazard is very remote. In situations of serious contamination, everything in contact with the soil is affectedincluding potable water pipes. Clean up of these types of environmental hazards, of course, must be the first priority. Fortunately, these conditions occur infrequen

23、tly. Therefore, in the vast majority of circumstances, plastic piping systems can be used with the confidence that they are economical yet very safe way to convey drinking water. References 1“Phase One Report on Evaluation of the Permeation of Organic Solvents through Gasketed Jointed and unjointed

24、Polyvinyl Chloride, Asbestos/Cement and Ductile Iron Water Pipes,” Cassady, Cole, Bishop, and Pfau, Battelle Laboratories, (1983). 2“Impact of Hydrocarbons on PE/PVC Pipes and Pipe Gaskets,” Ong, S. K., Gaunt, J. A., Mao, F., and Cheng C. L. American Water Works Association Research Foundation, (2008). 3“Assessment and Calculation of BTEX Permeation through HDPE Water Pipe, Final Report”, Koo, D. H. (2012). Available on the following website; http:/www.plasticpipe.org/pdf/permeation-report.pdf.

copyright@ 2008-2019 麦多课文库(www.mydoc123.com)网站版权所有
备案/许可证编号:苏ICP备17064731号-1