Friday, 11 November 2011

Unknown facts about steel and ductile pipes

All pipe materials are not equal. Many people think that there is not much difference between different pipe materials. The reason behind it would be that people do not take much interest or do not go in deep facts. There are some technical facts which differentiate steel pipes from ductile iron pipes. Here are some unknown and interesting facts about steel pipes and ductile iron pipes.

  • Cost effectiveness
One perspective to look at both pipe materials is, cost. Cost plays a very significant role in choosing a pipe material. Steel pipelines often require cathodic protection system which involves higher design and installation cost. They require a life time monitoring and maintenance and hence increased cost. Cement-mortar lined ductile iron pipe has an inside diameter larger than nominal pipe size. However, steel pipe inside diameter is equal to nominal pipe size. Therefore, for a given flow, velocity will be greater in steel than in ductile iron pipe. Higher velocities means higher head losses and when this difference is taken into account, ductile iron pipe delivers significant savings through lower pipelines head losses.
  • Back filling is easier in ductile iron pipe
Pipe material’s modulus of elasticity and the moment of inertia has a function called pipe stiffness. Ductile Iron pipe is a stiffer product than steel pipe because ductile Iron pipe design results in a thicker wall for a given set of parameters. Ductile Iron pipe is a stiffer product, hence, it relies less heavily on the sidefill soils to help support the external load. However, steel pipe requires more design with regard to laying conditions. Where the maximum standard modulus of soil reaction, E’, for Ductile Iron pipe is 700 psi per ANSI/AWWA C150/ A21.50, this is more nearly a minimum condition for steel pipe.
  • Ductile iron pipelines adapt to field conditions in installation
Ductile Iron pipe has deflectable push-on and mechanical joints. This means that the ample deflection capabilities of the joints may be used to help reroute the pipe around existing underground obstructions, such as existing utilities. It provides more flexibility to the contractor than steel pipe can offer. It also eliminates the common need for special lengths of pipe to be manufactured and shipped.
  • Difference in length
Ductile Iron pipe is furnished in 18 to 20 foot nominal laying length. On the other hand, steel pipe can be furnished in 20 foot length, however, is more commonly offered in 36 to 50 foot length. This exacerbates handling concerns.

There are plenty of advantages of Ductile Iron pipe. The conservative design approach gives the engineer an effective design that is easily accomplished while offering an impressive factor of safety.

Wednesday, 2 November 2011

Why use galvanized steel pipe?

Galvanized steel is simply steel coated with zinc. After going through a process called galvanizing, in which steel is coated with zinc and a normal steel becomes a galvanized steel. This process is performed to avoid steel from rust and corrosion.
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Galvanized steel has thousands of industrial applications, especially marine products. They are commonly used in marine applications because in that case the pipe fittings are subject to tough and wet conditions. It is not a new concept, in fact, it is being used from early times. Till 1850, over ten million tons of zinc was used to protect steel. There is a misconception about the galvanized steel.

Many people think that galvanized is a better product, but it is expensive and increases the overall cost. In fact, galvanized steel becomes less expensive when combined with its long life span. Galvanized steel studs cost almost half the price as compared to wooden studs that are most commonly used in buildings. Galvanized pipes are not used for  underground lines. It is relatively better to use for hot water lines, however, it also works good for cold water lines. Avoid using galvanized pipe fittings for gas supply lines as natural gas can cause the zinc to come off and cause blockages in the system.

Galvanized pipe fittings generally comes in size ranging from diameter of 1/8" to 20". These pipes are great value for money. No doubt galvanized steel pipes have various advantages, however, it has disadvantages also. One disadvantage is that the zinc coating can hide problems and defects beneath the coating which would otherwise be visible. And there are few more.

The important thing to remember is that whatever you choose, choose smartly. There is nothing on this planet that has only advantages, But there are things that have more advantages than disadvantages which makes them relatively better choice.

Tuesday, 1 November 2011

Why build green: Benefits of green building

Investors are realizing the need for going green to help reduce pollution from the environment. It not only helps make healthy buildings, but also develops a reputation and image of investors in the market. Image and reputation is a big thing in a market. This is only one advantage of building green, other benefits are:
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1. Environmental Benefits

As the name suggests, building green has various advantages. Like clear environment, improved air and water quality, reduced waste, conserve and restore natural resources.

2. Lower building cost

Some people think that green building costs higher, but the fact is that green building costs lower. It is true that the initial cost is high, but in the long run the cost gets lower and lower.

3. Improves productivity and attracts brilliant employees

According to a research, organizations in green buildings have an edge in attracting and retaining good employees. It is obvious that employees who are healthy and comfortable are more productive. It is proved by a number of studies. 31 green buildings from the City of Seattle were selected for the test and found that absenteeism was reduced by 40 percent. Another study which was sponsored in part by commercial real estate giant, Cushman & Wakefield, reported that 30 percent fewer sick days among one company's employees, and discovered a 10 percent increase in net revenue per employee in another company.

4. Sick building syndrome

This is a problem that is commonly present in non-green buildings. It has cost businesses millions of dollars each month. However, in green buildings with proper lighting, ventilation and use of non-toxic materials, you can totally avoid such problems.

5. Higher market value and reduced tax

Green buildings have a high image and reputation in the market as well as in the society. With high image, high prices are certain and also high resell value. Governments have enacted federal tax incentives to encourage the design and construction of energy-efficient green buildings, both residential and commercial.

6. Improved Quality of life

With green lighting, quality air to breath, reduced use of toxic materials and comfortable environment surely improves quality of life. It also improves quality of work life (Q.W.L).