Pipelines underground

Sulfur and Chlorine Pipelines. Underground sulfur is melted by superheated water and then piped as Hquid to the surface with compressed air. At the surface, molten sulfur is transported by heated pipeline to a storage or shipping terminal. One such pipeline, located under 15 m of water in the Gulf of Mexico, is insulated and surrounded by steel casing to which are strapped two 130-mm dia pipelines that carry return water from the deposit. The superheated water is carried from shore to the deposit in a 63.5-mm dia pipe inside the pipeline that carries the molten sulfur (21). 

Magnesium, zinc, or aluminum blocks are anached to ships hulls, oil and gas pipelines, underground iron pipes, and gasoline storage tanks. These reactive metals provide cathodic protection by acting as a sacrificial anode. 

The capital investment figures assume the development of a new site with all necessary auxiliary facilities such as loading docks, storage tanks, utilities generation, cross-country pipelines, underground storage, etc. In addition, an allowance for working capital at 10% sales is in-... 

The intelligent magnetic pig KOD-4M-1420 was developed and passed trials. This system is designed to provide corrosion and cracks detection in the operating underground gas pipelines at the distances up to 150 km. 

The Institute has many-year experience of investigations and developments in the field of NDT. These are, mainly, developments which allowed creation of a series of eddy current flaw detectors for various applications. The Institute has traditionally studied the physico-mechanical properties of materials, their stressed-strained state, fracture mechanics and developed on this basis the procedures and instruments which measure the properties and predict the behaviour of materials. Quite important are also developments of technologies and equipment for control of thickness and adhesion of thin protective coatings on various bases, corrosion control of underground pipelines by indirect method, acoustic emission control of hydrogen and corrosion cracking in structural materials, etc. 

Dyes. Dyes are added to gasoline to impart color for a number of reasons. Originally, these compounds were used to identify leaded gasoline so that it would not be used for other inappropriate purposes, such as solvents. Dyes are used to identify different gasoline grades so that pipeline companies can separate tenders, and so that service stations can easily check that the correct grade was placed in the underground tanks (aq). Dyes are usually based on a2o chemistry and are added in concentrations below 10 ppm (see Azo dyes). 

The demand for gas is highly seasonal. Thus pipeline companies economi2e by si2ing production faciUties to accommodate less than the system s maximum wintertime demand. Underground storage faciUties are used to meet seasonal and daily demand peaks. In North America, gas is stored in three main types of underground formations depleted oil or gas fields, aquifers that originally contained water, and caverns formed by salt domes or mines. 

A vital part of the process system for each of the plants includes a turboexpander-compressor set. This turbomachinery string has two main functions. The first function reduces the pressure and temperature of the incoming gas to facilitate separation of the methane. The second function raises the pressure of the methane after it leaves the fractionation tower and is transferred directly to the customers through an underground pipeline. 

Natural gas is transmitted in pipelines first across the country under high pressure m transcontinental pipe lines to local gas utility companies. The gas utility company reduces the pressure and distributes the gas through underground mains, and again reduces pressure from the street main into the home. 

Another problem is when the carbon dioxide content of natural gas is too high and must be lowered to produce pipeline-quality gas. Although the current practice is to vent this CO, sequestration of CO, in underground geologic formations is being considered. Already, in the Norwegian sector of the North Sea, CO, has been injected into saline aquifers at a rate of 1 million tons a year to avoid... 

Coal tar enamel This is derived from the coking of coal and is further distilled to produce coal tar pitches. It is used for hot application on-site. It will crack and craze if exposed to sunlight but has been employed successfully for over 50 years for the protection of underground or immersed structures. The main use is now for the exteriors of buried or immersed pipelines. Different types of enamel are available to give various degrees of heat resistance. It is now generally used for pipelines below 155 mm diameter. 

Only a small amount of the metal used in underground service is present in the ground water zone. Such structures as well casings and under-river pipelines are surrounded by ground water. The corrosion conditions in such a situation are essentially those of an aqueous environment. 

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