Unit 9 materials

1. Study the following words before reading the text.

alloy available brass brittleness carbon content corrosion resistance costly decrease drawback fittings gauge grade hardness

сплав имеющийся в наличии латунь хрупкость углерод содержание устойчивость к коррозии дорогоcтоящий уменьшаться недостаток фиттинги, арматура контрольно-измерительный прибор марка, сорт твердость

high tensile steel insertion joining labour saving medium carbon steel newcomer promising reasonable strength temperature range toughness weldability

высокопрочная сталь вставка соединение экономящий труд малоуглеродистая сталь недавно появившийся (материал) перспективный умеренный, приемлемый прочность температурный диапазон жесткость свариваемость

2. Pay attention to the pronunciation of the following words.

wrought available utilized

light weight inexperienced unfortunately

geologists requirements automatically

2. Find the pronunciation and the proper English equivalents of the words.

aluminium titanium nickel chromium

manganese copper zink polyvinylchloride

polypropylene cellulose acetate polyethylene

IV. Translate the following words. Pay attention to the meaning of prefixes and suffixes.

soluble visible	insoluble invisible	16. material replaceable	immaterial irreplaceable
dependent accurate discovered known happy fortunately suitable possible movable to place to write to construct to move	independent inaccurate undiscovered unknown unhappy unfortunately unsuitable impossible immovable to replace to rewrite to reconstruct to remove	18. regular 19. legal 20. similar 21. order 22. advantage 23. weldable 24. useful 25. fruitful 26. hopeful 27. to heat 28. to treat 29. fabricated	irregular illegal dissimilar disorder disadvantage weldless useless fruitless hopeless to preheat to pretreat prefabricated

V. Read and translate the following text. Materials

The first pipe line was manufactured from wrought iron. Since the end of the last century, when steel became available in bulk and at prices considerably below those of wrought-iron, this material replaced wrought iron almost completely. There are different grades or types of steel.

The chemical composition and physical properties of steel depend upon different methods of its manufacture and upon certain elements other than carbon, added during its manufacture. At the present time for the manufacture of pipes medium carbon steel is usually used, though high tensile steel has been utilized for exceptional circumstances and for high pressure lines. Other materials being used for pipe lines include aluminium, titanium and their alloys.

When two or more metals are alloyed they form a new metal which is called an alloy. Steel is often alloyed by the addition of other metals, as nickel, chromium, manganese, etc., to increase its strength and toughness and increase its life by increasing its corrosion resistance properties. In general corrosion resistance increases with the chromium content and decreases as carbon content rises. Unfortunately, most corrosion-resisting alloys of steel are unsuitable for oil and gas pipe, because of the following:

1) they are too costly;

2) difficulty is experienced in working with them because of hardness, brittleness and poor weldability. With the exception of some brass (copper and zink) fittings alloy combinations are not extensively used in gas and oil industry for pipe making. Iron and steel pipes are most commonly used because of their mechanical strength and reasonable price as compared to pipe made from other metals.

In past few years plastic pipes are known to have found wide application. Main use so far is in replacement or insertion into existing service. Biggest advantages of plastic pipe are resistance to corrosion and labour savings. (due to light weight and simple method of joining). The main drawback or disadvantage remains lower mechanical strength and limited temperature range.

Here is how plastic pipes rank in order of popularity in the gas industry: polyvinylchloride, polypropylene, cellulose acetatbutyrate, and polyethylene. A promising newcomer is polyacetal pipe.