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.
dear Mr Davis I work in Iran i think it depend on quality of material and cost price analysis for example in Iran project s UPVC and HDPE are more cheap than ductile pipe in diameter between 100 up to 350 mm but for diameter above 400 mm to 1000mm ductile iron have prefer
Metal pipe is much available in that area. because plastic pipes can`t afford the temperature of middle east. But galvanized iron pipe is toxic for human beings, ductile pipe isn`t so convenient for installation. So SS 316L is the best choice for domestic water.
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.
HDPE is the best for now if you can afford it. Ductile iron is good also but ensure joints are thrust adequately. Stay away from galvanized iron is highly corrosive, I would recommend PVC as normal practice.
Dear Davis, in the UK all pipe materials for use in supply of water have to be approved by the Drinking Water Inspectorate under its regulation 25. You can see a full listing of all materials at http://dwi.defra.gov.uk/drinking-water-products/approved-products/soslistcurrent.pdf
As you stated the question most materials can be used provided they have been approved.
Relies from others alude to the difference in performance in different situations and you would do well to look at a pipe material selection guideline manual; especially one from the Middle East where there are distinct conditions. For example plastic pipes will degrade in strong ultra-violet light and so unless pipes are stored under cover this could be a constraint. Similarly there are some examples of extremely aggressive ground conditions in terms of corrosivity. So here it would be prudent to consider carefully whether metallic pipelines were suitable. I've even seen concrete and clay pipes attacked in Al-Ain.
Trends in Europe in recent years have been towards plastic pipes but for specialist applications other materials come into their own. North America has seen a slower uptake of plastic materials but plastics are now making greater inroads. It's not just the pipe materials which are important but rather that designers and specifiers understand the systems and materials and their constraints. In particular it is not just about the pipes themselves but rather how whole systems come together and how pipes are jointed and fitted to things like valves and hydrants as well as how house connections are made.
Ductile Iron Pipe is by far the best material! You can build homogenous pipeline from DN 60 mm to DN 2000 mm even more. The normal products have a wide range of application in from low to high pressure. With special external coating and special internal lining you can cover all types of practical situations. The range of fittings and valves is very large and comprehensive. The locking systems are efficient and allow to avoid concrete blocks. Many international standards such ISO 2531 or european standards EN 545 garantee the quality of the products. see : www.pamline.com and www.dipra.org Thanks
Dear Davis, I spent well over 20 years either as COO or CEO at a large water system in the US. Stay away from galvanized iron. Zinc is notoriously corrosive. Ductile Iron is OK, but ensure joints have adequate thrust restraint and I would recommend polyethylene lining as normal practice. HDPE is great if one can afford it. Thick walled can also be used for directional drill carrier pipe.
As I have been involved in installing many many water systems, by far the best option is 316L stainless steel. Although it is expensive it can eadily be sterilised without any problems. It is used extensively in the food industry as standard. www.tcengineeringservices.co.uk
The general consensus is to use plastics for their available range of diameters. MDPE has been used extensively in the UK but most countries prefer HDPE. Be very careful with uPVC as the lower classes can break due to negative pressures under surge conditions. Ductile iron is a great material fro larger diameters. I, personally, would never recommend steel as it pinholes when it fails and it is difficult to find the leaks.
Which pipe material is the best for water supply networks in terms of quality of water supplied ?
Plastic pipes (UPVC):
The raw material needed to make most plastics comes from petroleum and natural gas. Due to their relatively low costs, ease in manufacture, versatility, and imperviousness to water, plastics are used in an enormous and expanding range of products: from paper clips to pipes intended for transporting drinking water. Plastic has replaced many common materials such as cement and metals within drinking water networks. Plastics are often preferred than metals due to a number of inherent advantages: plastic piping is lightweight and does not require an open flame for joining the flexibility of plastic can simplify the installation. Plastics are typically lower in cost and resist the corrosion and scaling that plague metals in some applications. However, indication of the mitigation of synthetic chemical contaminants from plastic pipe materials to water may exist. These contaminants likely occur at low “safe” levels, but are sufficient to generate odour and taste concerns in some cases. Another disadvantage of some types of plastic pipes is that they have lowered resistance to chlorinated water.
Take a look at this website www.coretechsED.co.uk/safe-drinking-water.html. It's slightly off subject but we are a UK manufacturer who, we believe, have a device that can make a big difference in helping bring sterile, safe drinking water and irrigation to remote and impoverished urban communities. Any advice on taking this to market in the Middle East would be very gratefully received. Thanks for your attention