After pipeline

Often it is known or suspected that future platform operating requirements nay change, which requires separation system flexibility. For example, the initial plan may be to inject gas into the producing field, but a gas pipeline outlet for the gas may be expected several years later. At that time the gas would not have to be delivered at as high a pressure, but more extensive gas conditionlng would be required to meet hydrocarbon dewpoint requirements It may be possible to utilize surplus gas conpression horsepower for gas conditioning purposes at that time As another example, it may be planned to initially load low vapor pressure crude oil into tankers at the offshore platform, but later after pipeline completion to deliver high vapor pressure crude oil to the pipeline. 

The reduction in viscosity of residua tends to reach a limiting value with conversion, although the total product viscosity can continue to decrease but other properties will be affected. Sediment (which is predominantly organic but may contain some mineral matter) may also form—a crucial property for residual fuel oil—and conditions should be chosen so that sediment formation is minimal, if it occurs at all. When shipment of the visbreaker product by pipeline is the process objective, addition of a diluent such as gas condensate can be used to achieve a further reduction in viscosity. Recovery of the diluent after pipelining is an option. 

It may be thought that emulsified transport does not require a completely dehydrated oil, sinee oil-water separation is to be carried out after pipelining. This is not the ease, however, because of the possibility of osmotic swelling, which was discussed previously, fliat could become particularly annoying if the emulsion viscosity is already a concern. 

Fig. 10.47 Potential event sequences after pipeline failure with indication of their expected frequencies of occurrence and conditional probabilities for the occurrence of the different conceivable phenomena...

A3.5.2.4 Start primary sampler after pipeline volume between samplers has been displaced. 

In recent years much more attention has been given to pipeline isolation, after instances in which the contents of export pipelines fed platform fires, adding significantly to damage and loss of life. Many export and in field pipelines are now fitted with emergency shutdown valves (ESDV) close to the production platform, to isolate the pipeline in the event of an emergency. 

Essentially all of the methane [74-82-8] is removed ia the demethanizer overhead gas product. High recovery of ethane and heavier components as demethanizer bottoms products is commonplace. The work that is generated by expanding the gas ia the turboexpander is utilized to compress the residue gas from the demethanizer after it is warmed by heat exchange with the inlet gas. Recompression and deUvery to a natural gas pipeline is performed downstream of the plant. A propane recovery of 99% can be expected when ethane recoveries are ia excess of 65%. 

The variatioa of average pipeline coastmctioa costs with increasing size of line pipe is showa ia Figure 2, based oa data takea from FERC coastmctioa permit appHcatioas from July 1991 to July 1992. The cost of a common carrier pipeline project must be reported to the FERC ao later than six months after successful hydrostatic testing. 

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. 

The code fragment is now finished after the eighth clock cycle. Note that there are stiU three clock cycles during which there are idle stages in the multiplication pipeline. The compiler would look for other statements in the code that could be overlapped with those already in process. 

This is provided to prevent reverse rotation of the pump in the event of a power failure or a deliberate shutdown due to backflow of liquid from the rising mains (pipelines). This is located immediately after the last pump stage casing/discharge outlet to prevent the shaft from rotating in the reverse direction. The provision of a non-return valve also ensures that the pump always starts in a shut-off condition, when the power requirement is at a minimum. 

If scratches and breaks occur in the zinc layers by accidental damage - which is certain to occur when the sheets are erected - then the zinc will cathodically protect the iron (see Fig. 24.4) in exactly the way that pipelines are protected using zinc anodes. This explains the long postponement of rusting. But the coating is only about 0.15 mm thick, so after about 30 years most of the zinc has gone, rusting suddenly becomes chronic, and the roof fails. 

After 1860 in the United States, water mains were only occasionally given coatings of tar. About 18% the activities of Engii.sh undertakings were extended to America, where chiefly bare metal pipelines had previously been laid. Water supply pipes were coated internally with bitumen in America after 1912. Vical (1837) in France and J. Bull (1843) in America introduced the widely known cement mortar as a protective material for water pipes 16]. 

Fig. 10-8 Pipe/soil potentials and protection currents for a pipeline. Drainage test x-x after 1 year o-o. P = potential test point R = pipe current test point LA = cathodic protection station / = insulating joint SP = pipe casing potential test point.

The cathodic protection of pipelines is best monitored by an intensive measurement technique according to Section 3.7, by an off potential survey eveiy 3 years and by remote monitoring of pipe/soil potentials. After installation of parallel pipelines, it can be ascertained by intensive measurements whether new damage of the pipe coating has occurred. These measurements provide evidence of possible external actions that can cause mechanical damage. 

Cooling water pipes are essential for the operation of power stations and must not cease to function. Pipelines for fire fighting are also important for safety reasons. Such steel pipelines are usually well coated. At areas of unavoidable damage to the pipe coating, there is an increased danger due to cell formation between steel and concrete where local corrosion rates of >1 mm a are to be expected [4], Damage to pipelines for fire fighting has frequently been observed after only a few years in service. 

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