Stringing Pipe

Pipeline Construction on Land

P. 249-253

Be sure you know the following words and their translation

№	English		Ukrainian		Russian
	Pipeline	-	трубопровід	-	трубопровод
	Rod	-	штанга	-	штанга
	Clearing-crew	-	очисна бригада	-	очистная бригада
	Ditching	-	копання канав	-	устройство канав
	Permafrost	-	вічна мерзлота	-	вечная мерзлота
	Terrain	-	грунт	-	почва, грунт
	Insulator	-	ізолятор	-	изолятор
	Wheel ditcher	-	екскаватор призначений для копання траншей	-	траншейный экскаватор
	Spoil	-	пуста порода	-	пустая порода
	Rock ditcher	-	землекоп	-	землекоп
	Bulldozer	-	бульдозер	-	бульдозер
	Finned radiator	-	ребристий радіатор	-	ребристый радиатор
	Heat pipe	-	теплопровід	-	тепловая труба
	Stringing	-	укладка плетей трубопроводу	-	укладка плетей трубопровода
	Wire rope	-	талевий канат	-	талевый канат
	Boom	-	стріла, виліт крану	-	стрела, вылет крана
	Coating	-	обшивка	-	обшивка
	Trailer	-	причіпний вагон	-	прицепной вагон
	Buckling	-	Випинання бурильних штанг чи труб	-	выпучивание бурильных штанг или труб
	Bending mandrel	-	оправлення для гнуття	-	оправка для гибки
	Line-up clamps	-	Затискач для центрування труб при зварці	-	зажим для центровки труб при сварке
	Side-boom tractor	-	трактор, що має бокову стрілу	-	трактор, оборудованный боковой стрелой
	Winch	-	лебідка	-	лебёдка
	Skid	-	гальмовий підкладень	-	тормозной башмак

Match the words in column A with their definition in column B

A	B
	Trailer	a)	a powered machine for digging earth, gravel, sand, etc., esp a caterpillar tractor so equipped
	Insulator	b)	system of pipes and heating equipment for transferring hot water or hot air
	Rod	c)	a powerful tractor fitted with caterpillar tracks and a blade at the front, used for moving earth, rocks, etc
	Spread	d)	to extend or unfold or be extended or unfolded to the fullest width
	Bulldozer	e)	a device for cooling an internal-combustion engine, consisting of thin-walled tubes through which water passes. Heat is transferred from the water through the walls of the tubes to the air stream, which is created either by the motion of the vehicle or by a fan with rips
	Clearing-crew	f)	equipment used for making ditches in rocky areas
	Heat pipe	g)	ground or a piece of ground, esp. with reference to its physical character or military potential radio reception can be difficult in mountainous terrain a rocky terrain
	Permafrost	h)	any material or device that insulates, esp. a material with a very low electrical conductivity or thermal conductivity or something made of such a material
	Terrain	i)	The se­quence of names of all landowners.
	Line-list	j)	a road vehicle, usually two-wheeled, towed by a motor vehicle: used for transporting boats, etc
	Wheel ditcher	k)	a clear space
	Side-boom tractor	l)	a slim cylinder of metal, wood, etc.; stick or shaft
	Rock ditcher	m)	ground that is permanently frozen, often to great depths, the surface sometimes thawing in the summer
	Line-up clamps	n)	tractor specially equipped for pipe stringing
	Finned radiators	o)	equipment which is used for align the ends of the pipe prior to welding

Pre-reading tasks

A) scan the text and answer the questions

- What is usually done before the construction of modern pipeline begins?

- What does superintendent need to begin the construction?

- Why does he need maps and line-list?

- What does specification of the contract cover?

- What does the word “speared” mean?

- What determines the amount of construction equipment?

- Why should the constructor rent the necessary machinery?

- How far can spread move during a working day?

- What does the term “right of way” mean?

- What is the main function of clearing crews?

B) skim the text and find the words concerning oil and gas sphere

Before construction begins on a modern pipeline, months and sometimes years of engineering studies and surveys of potential reservoirs and markets precede the final decision to build the line. Companies survey routes by aerial photography and surface mapping. During the surface mapping, the company must secure a right-of-way from each owner of the property that the pipeline will cross. Before a pipeline superintendent goes out to begin or site- has several1 s to determine all opera­tions: maps, a line list, and contract specifications. Maps show in accurate detail all surface features affecting construction. The line list sets out in se­quence the names of all landowners, the number of linear rods (metres) of line to be built on each piece of property, and any written limitations or restrictions. Included are copies of permits for crossing roads, rivers, and other public property. Specifications in the contract cover every planned operation and as many eventualities as possible.

Assembling the Spread

The pipeline contractor assembles the spread—the equipment and crew needed to build a pipeline. A spread may be composed of 250 to 300 workers in an average operation and up to 500 in a very large operation. The amount of construction equipment depends on the size of the pipeline to be built and the difficulty of the terrain. Stream crossings, marshes, bogs, heavily timbered for­ests, steep slopes, or rocky ground can require different pieces of machinery. The pipeline contractor might rent rather than buy the necessary machinery since outfitting a big-inch (large-diameter) pipeline spread can be a multimillion-dollar operation. A spread can move at a rate of 3 miles (4.8 kilometres) a day, with a distance of sometimes 10 or 15 miles (16 or 24 kilometres) separating the workers at the beginning of the crew from those at the end.

Clearing Right-of-Way

A right-of-way is the legal document granting a right of passage over another person's land. By common usage it has come to mean? cleared strip of land from 50 to 75 feet (15 to 23 metres) wide, depending on the size of the pipe and the type of terrain. The clearing crews open fences and build gates, cattle guards, and bridges as the first segment of the spread moves up on the job. Bulldozers are standard equipment for clearing timbered areas.

Salable timber cut by the clearing crews is stacked; the rest is cut and burned. Grading and completion of a roadway capable of supporting all vehicles follow. The road must be large enough for the largest tractor and other nec­essary equipment. In rocky terrain, a machine equipped with a ripper that extends several feet into the ground is often used to loosen rocks for re­moval before digging the ditch for the pipe to rest in.

Construction of pipelines in arctic climates involves routes that cross permafrost (permanently frozen ground), forests, snow-covered mountains, tundra, rivers, and streams. The Trans-Alaska Pipeline, for example, runs through very diverse terrain. On the North Slope, the route required a spe­cial gravel and insulation workpad to prevent the subsurface permafrost from degrading or melting. The gravel road base acted as an insulator, pro­tecting the permafrost as vehicles, equipment, and crew members of the spread built the aboveground portion of the pipeline. Parts of the line were laid in a zig-zag pattern to allow for expansion and contraction of the pipe during temperature changes.

Digging

Digging a ditch in which to bury the pipe, or ditching, requires various kinds of equipment. For loose dirt or stable soil, the wheel ditcher is most

common. Rotating toothed buckets on the wheel ditcher pick up the excavated dirt, or spoil, and pile it to the side of the ditch for later use as backfill. Rocky terrain requires the use of pneumatically drilled holes and dynamite, a rock ditcher, or a bulldozer with ripper. A ripper is a clawed, plowlike attachment. Sometimes the crew uses backhoes to dig through rock and to clear blasted rock out of the trench.

The ditch must be at least 12 inches (30.5 centimeters) wider than the pipe diameter and deep enough to ensure that it will not interfere with plow­ing and other normal land use. The Department of Transportation requires a minimum of 30 inches (76 centimeters) of cover across farmland in normal soil and 36 inches (91 centimeters) in municipal areas.

In arctic areas where permafrost conditions exist, pipeline contractors may elect not to use a ditch for the pipeline. The pipeline, or sections of it, may be built above the ground on specially designed horizontal crossbeams mounted between pairs of vertical support members (VSMs).

Ap­proximately 400 miles (644 kilometers) of the Trans-Alaska Pipeline is con­structed in this manner. When the aboveground technique is used, the pipeline is surrounded by insulation panels made of steel-jacketed fiberglass with weath­erproof expansion joints. Finned radiators atop the VSMs improve heat trans­fer between the atmosphere and the heat pipes to which they are attached (fig. 6.52B). The heat pipes, which are 2 inches (5 centimetres) in diameter, keep the soil stable in permafrost areas by cooling the ground. Drawing off heat is neces­sary because the friction of the flowing oil heats the ground enough that the pipe can sag. When a company decides to ditch in unstable permafrost soil, it may refrigerate the buried section of pipe to keep the subsurface soils in the area from melting. About 7 miles (11 kilometres) of the Trans-Alaska Pipeline is constructed in this special burial mode.

Figure 6.52 In aboveground construction, VSMs hold insulated pipe at various heights (A), while special finned radiators and heat pipes draw heat away from the ground (B). (Courtesy ofAlyeska Pipeline Service Co.)

Stringing Pipe

Stringing is the process of delivering and distributing line pipe along the right-of-way. The pipeline contractor or its subcontractor purchases and strings the pipe. On some jobs the pipe is cleaned, primed, and coated before it is delivered to the right-of-way. This type of pipe requires special handling to prevent damage to the coating as well as to the pipe ends. To move it, a sling is formed from wire rope threaded through a boom, a long arm attached to a tractor. Special curved aluminum plates at the end of the sling fit inside the ends of the pipe, where contact with the coating and the beveled ends is kept to a minimum. As pipe is lifted off the trailer, the equipment operator must evenly distribute the weight of the load to prevent the pipe from buckling. On jobs where the terrain is relatively flat and the road system permits it, the pipe may be double jointed before being strung along the right-of-way.

Double jointing is the welding of two sections of pipe to form one piece ap­proximately 80 feet (about 25 metres) long. The equipment operator gener­ally uses a spreader bar between the two lifting lines to prevent these long joints from buckling.

Bending Pipe

When the ditching and stringing are finished, engineers measure the contours of the ditch to determine how many degrees of bend must be put in the pipe so that it will conform to the bottom of the ditch. Often as many as seven out of every ten pieces of pipe must be bent to fit the ditch. Special equipment allows the pipe to be bent on location (fig. 6.55). A bending shoe—an attachment that works off the side-boom tractor and winch—bends small-diameter pipe. Large-diameter pipe requires a bending mandrel, which keeps the pipe from buckling or wrinkling when it is bent.

Дата добавления: 2015-10-28