Pipelines copper

Solids materials that are insoluble in hydrocarbon or water can be entrained in the crude. These are called bottom sediments and comprise fine particles of sand, drilling mud, rock such as feldspar and gypsum, metals in the form of minerals or in their free state such as iron, copper, lead, nickel, and vanadium. The latter can come from pipeline erosion, storage tanks, valves and piping systems, etc. whatever comes in contact with the crude oil. 

Coal pipelines have been built in countries such as France (8.8 km), and Russia (61 km), and pipelines are also used for transporting limestone, copper concentrates, magnetite, and gHsonite in other parts of the world. The first coal pipeline, built in Ohio, led to freight rate reductions. The pipeline stopped operation after introduction of the unit train, used exclusively to transport coal from the mine to an electric power generation station. 

In general NYY-O cable is used with a minimum copper cross-section of 2 X 2.5 mm. The cable is connected to the pipeline by a suitable process [5-7], and the connections carefully coated. The cable is usually connected to aboveground test points and covered with hoods, tiles or a cable ribbon. 

Despite these qualifications copper and its alloys are used extensively and successfully in much chemical equipment. Uses include condensers and evaporators, pipelines, pumps, fans, vacuum pans, fractionating columns, etc. Tin-bronzes, aluminium-bronzes and silicon-bronzes are used in some circumstances because they present better corrosion resistance than copper or brasses. 

A continuous polymer anode system has been developed specifically for the cathodic protection of buried pipelines and tanks. The anode, marketed under the trade name Anodeflex , consists of a continuous stranded copper conductor (6AWG) which is encased in a thick jacket of carbon-loaded polymer, overall diameter 12-5 mm. To prevent unintentional short circuits an insulating braid is sometimes applied to the outer surface of the conductive polymer. 

Locating and Bonding when cathodic protection is applied to an existing jointed pipeline, all joints must be located without digging up the pipe. On location, each joint is exposed and an electrically conducting bond (usually galvanised steel strip or copper cable) is welded into position. 

As reaction is preceded by a certain delay, this induction period was reduced by the addition of copper salts, e.g. potassium cuprocyanide K3Cu (CN)4. This substance was supplied to the system dissolved in the hydrazine hydrate. It was found that potassium cuprocyanide reacts with hydrazine even at room temperature to form metallic copper which, if deposited in the pipelines, may cut off the flow of hydrazine into the combustion chamber. To prevent this the system was modified so that hydrazine hydrate flowed from the tank into the combustion chamber through a cartridge containing cupric nitrate, which dissolved in hydrazine hydrate in a sufficient quantity to accelerate the reaction (hydrazine and its reaction with H202 will be discussed in more detail further on). 

This acid is very corrosive towards most of the common metals and alloys. The corrosivity is increased where aeration or contamination by oxidising agents is present. Copper is particularly prone to this problem. Also many failures occur due to the presence of minor impurities such as ferric chloride. Rubber-lined steel is widely used for pipelines and large or small vessels. The rubber compound should be free from copper bearing antioxidants or accelerators. 

As a rule, corrosion is not uniformly distributed on the exposed surface. An average rale of corrosion of 0.05 cm/year may be concentrated in spots, leading to holes in a piece of metal (e.g., a pipeline) that is 0.5 cm thick or more. Perhaps the worst design error, from the corrosion point of view, is to combine two different metals without isolating them electrically. For example, connecting copper plates with... 

Hydrochloric add Nitric add Dissolves most water scales and corrosion products Dissolves most water scales and corrosion products On boilers, heat exchangers, pipelines, etc. On stainless steel and aluminum Corrosive to steel temperature must be below 175T Cannot be used on copper and ferrous alloys... 

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