I am Davis working on project and construction management, planning, monitoring, control and execution of various infrastructure projects in the Middle East. For my new water supply project I would appreciate to some inputs from you.
As we all know, different materials are used for water supply networks such as DI( ductile iron), HDPE, UPVC, GRP, GI (galvanized iron), Copper etc . I would like to know your opinion about which material is the best for maintaining the quality of water supplied to the public , irrespective of the cost. What are the reasons behind it? I I'm interested in knowing some recent trends in using these materials, some case study will also be nice to discuss if some one has it.
In Arabic countries with sandy soils it is no problem with pipelines from glas. They are used over the world in food productin. For zero impact at quality. You have all components and many producers.
All answers you've got are more or less correct and reflect the colleagues' experience. Nevertheless, I have to suggest to always consider the water's corrosivity when you are to make your choise.
Different types of pipe materials may be of merit depending on the particular water supply network. Networks pipes (from a treatment works to a property) may be of different materials than those used for a plumbing installation inside a building. Other factors, such as their structural integrity, may be more important than their effects on water quality.
From a microbiological point of view, non-metallic materials (e.g. plastics) for use in contact with drinking water should not exert an adverse effect on water quality by leaching compounds that could support the growth of micro-organisms. Approval schemes exist to test the suitability of non-metallic pipes (e.g. here in the UK there is British Standard BS6920 Part 2.4). No plastics material should be used that has not passed such a test.
Obviously, metal pipes do not leach organic compounds capable of supporting microbial growth. However, their surfaces can be rougher than plastics materials and can create micro-environments that can provide a sheltered habitat to permit biofilm growth.
But, what grows on a pipe is strongly influenced by the characteristics of the water supply. A water with an effective chlorine residual or without nutrients (biostable) will have a greater impact on limiting microbial growth than the type of pipe material. The converse applies.
Once inside a building, other factors become more significant. Both temperature and stagnation can exert a strong influence on water quality. There has been much debate about whether copper or plastics make better materials for plumbing installations. It has been claimed that copper can reduce biofilm formation and thus reduce the likelihood of Legionella growth. Flexible tap-connectors made from various artificial rubber materials (e.g. EPDM) have been found to support biofilm growth and have been suspected of causing infections in hospitals.
I hope this helps you to reach a decision.
Kind regards
Robert
Published
by Robert Pitchers, WRc plc - Technical Consultant
HDPE are widely used in India. The climate and weather conditions are basically arid to semi-arid in nature. And transporting water (Drinking water) to remote areas are usually accomplished by HDPE only. Primarily may be because of its cost effectiveness, durability and ease of transport / handle. As rightly suggested by Maher Chebib, it also depends on were to use, type of client and total investment allocated.
Cement-mortar lined ductile iron pipe is a very durable solution and no weird substances leach into water over time. The cost is higher than HDPE but still much cheaper than stainless steel, copper or similar material.
As you are in the middle east one important aspect to remember is that the client can be a bit difficult in term of material acceptance. Having said that the best material, if cost is really not in question is 316L SS. Now that costs so the best cost benefit is HDPE, for small diameters, cement lined DI for larger ones. However remember that HDPE is difficult to install in a hot climate as its heat expansion is significant and there are not too many qualified contractors that can install these pipes here. Having said all this, for the Middle East, go for cement lined DI. It is a known material, approved by the authorities, and familiar to the contractors. Good luck.
Today commonly we find the question of the most appropriate material to put in a water network, and the scientific and technical knowledge on this topic differs from manufacturer to manufacturer. Each one tries to explain and expose the advantages of their materials to be applied in networks of clean water. But this choice has to do with different criteria depending on the type of facility, in which diameter is to be used, the storage in site work, the installation costs, and in your case the criterion most influential is the material which ensures the most quality of water supplied.
The WASE company (http://wase.pt/), based in Portugal, has an innovative service decision support consultancy in the area of choice of the most appropriate type of pipe depending of the situation. We deal with these issues professionally, based on two software’s: one is the study of each solution installation costs- The INVESTPIPE software (is under development for diameters up to 200), and another software- the WISED- with criteria insertion, and pondering for each one, it gives robust and reliable results for the final decision. Therefore you will take a decision of witch material to apply in your network, based on something concrete, reliable and focused in your special case. The choice will be always yours, but conscientiously and according to the criteria that have more weight for you!
I see you have a choice to make for your project and many doubts are coming, well, we can help you, based on your decision criteria’s (water quality transported, the investment cost, and reliability of the material, durability and versatility of the solution). The difference in the degree of importance of these criteria is not linear, that is, the criterion that carries more weight for you is the transported water quality, and it will undoubtedly be the criterion with more weight. The weight of this criterion comparing to others, such as the investment costs, the durability of the material, its resistance, facility of installation, reliability when in operation, etc. will all have different weights in your choice, these differences are not linear and equal. The WISED software eliminates all the errors that multicriteria matrices have.
Feel free to contact me at +351 969 034 092 or marta.gomes@wase.pt . I leave you below an excerpt in English of our website so you can have a little more information about the software support for multi-criteria decision. (I've attached my business card also).
To see an example of a WISED report (demonstration) for a choice of material for a DN110 between ductile iron pipes, PVC and PEAD, please contact me to my email, I can give you a brief pdf with the graphics and weighted I used for this specific example.
"Decision support: What is this service? The service decision support of WASE, offers its customers a collaboration in deciding which materials and / or equipment to be placed in a supply system and water distribution. Includes pipeline network, pumping stations, valve boxes and treatment plants. With over 12 years of experience in the sector and working directly with different materials pipelines and equipment’s (pipes, fire landmarks, valves, etc.) The WASE Company provides a consultancy service to support decision so that our customers can opt for the best solution, with trust and transparency, increasing the effectiveness of management decisions in particular with regard to investments. The efficient management of the system has to be made to minimize operating costs and the assets have to guarantee to be suitable when placed in contact with water for human consumption, they must be approved materials for contact with drinking water, and they have to be of high reliability and durability. There are doubts as to the decision to be taken to the choice of materials of a water supply system? And the choice of materials to be placed in a drinking water distribution system? The WASE Company intends to meet with the provision of the decision support service. Thus, we know that we headed for a breakthrough mission in this area, in which the managing body of supply and / or water distribution systems, needs of an external entity that provides support for the choice of materials that will be part of the assets that are to manage. This service is not intended to WASE choose for our client, what we want is to draw attention to the most important details related to the choice of a material and / or equipment, and base the decision support report, taking into account the needs of each client. In partnership with BANA Consulting, a strategic consulting firm, a pioneer in Portugal in the area of decision support and multi-criteria, the WASE Company is prepared to answer technical questions about materials and equipment within its business area.
SOFTWARES: Evaluating options considering multiple benefits, costs and risks is a challenge that the management of water bodies encounter in day-to-day. Through WISED and INVESTPIPE application, we can support decision-making processes in a collaborative, transparent and objective. WASE promotes this application as the main tool in decision-making materials of a supply system / distribution of water, however, it's a software applicable in other areas, already proven and international recognition, such as procedural proposals in supply competition in assessment strategies, staff performance and investment projects. With WISED, processes are transparent and objective assessments. The main advantages to the use of this application are:
• Promote the objectivity and transparency in decision-making processes;
• Ensure the choice of what is in fact the best alternative;
• Ensure best practice in scoring and weighting procedures;
• Allow the standardization of assessment processes across the board;
• Increase the level of confidence in the evaluation and selection process;
• Allow the participation of various stakeholders in a collaborative way."
Depending on the size of th pipeline ,quality of water transmitted and the quality of trench material ,steel pipe with cement lining is recommended.Hdpe pipe is also to be the option.abdul jamil Water ,sanitation engineer.
1. If the bottom of the chanel (where pipe must deployed) is less than 70 cm, you have to calculate the environmet conditions. Here in greece we call it ''frozen factor'' but for M. Eat have the mean of high temperatures. So you don't want to face situations that the water is arriving at temp. >25-30 0 C.
2. If the depth is higher and because of geological factors, you need pipes with high flexibility (HDPE>9%), that assure you with longer duration and lower service costs.
3. Here in Greece we constructed networks for potable water with HDPE and d=1m
Dear All, I gone through all your comments and hope we can conclude like this. If cost doesn't matter the best material is 316L SS. Considering the economical aspects and easiness in handling HDPE is the best upto 500mm dia and DI for higher diameters. Any objection to this. DI, HDPE and UPVC pipes are in common here in Oman. Thanks for your valuable suggestions and comments. Regards, Davis