Steel pipe manufacturing

STEEL PIPE

Manufacturing

What is steel pipe?

• Steel pipes are long, lightweight hollow tubes that are used for a variety of purposes.

• They are used for water and gas supply, automobiles, heating and plumbing systems, flagpoles, street lamps and etc.

History

• People have used pipes for thousands of years.• Perhaps the first use was by ancient

agriculturalists who diverted water from streams and rivers into their fields.

• Chinese used reed pipe for transporting water to desired locations as early as 2000 B.C.

• During the first century A.D. , the first lead pipes were constructed in Europe.

Reed pipe

Lead pipe

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• An early for producing metal tubes was patented by James Russell in 1824. In his method, tubes were created by joining together opposite edges of a flat iron strip.

• The metal was first heated until it was malleable. Using a drop hammer, the edges folded together and welded.

• The pipe was finished by passing it through a groove and rolling mill.

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• After Russell's method, Comelius Whitehouse developed a better method for making metal tubes.

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• After Whitehouse, John Moon (in 1911) suggested the continuous process method in which a manufacturing plant could produce pipe in an un ending stream.

Design

• There are two types of steel pipes:1. Seam pipe2. Seamless pipe• Seamed tubes are heavier and more rigid. They

are used for as gas transportation, plumbing.• Seamless tubes are typically more light weight,

and have thinner walls. They are used for bicycles and transporting liquids.

Raw Material

• The primary raw material in pipe production is steel. Other metals that may be present in the alloy are

o Aluminumo Manganese o Titanium o Tungsten o Zirconium

Manufacturing Process

• The overall production method three steps;• First, raw steel is converted into a more

workable form. • Next, the pipe is formed on a continuous or

semi continuous production line. • Finally, the pipe is cut and modified to meet

the customer's needs.

Ingot production

• Molten steel is made by melting iron ore and coke in a furnace.

• The molten steel is then poured into large, thick-walled iron molds, where it cools into ingots.

Producing Blooms

• To produce a bloom, the ingot is passed through a pair of grooved steel rollers.

• Groove steel rollers move in opposite directions.

• This action causes the steel to be squeezed and stretched into thinner, longer pieces.

• Blooms are converted into billets by putting them through more rolling devices which make them longer and more narrow.

Producing Slabs

• Ingots may also be rolled into slabs in a process that is similar to the bloom making process.

• The steel is passed through a pair of stacked rollers which stretch it. However, there are also rollers mounted on the side to control the width of the slabs.

• The slabs are sent through a series of rollers on a hot mill and made into thin narrow strips of steel called skelp

Blooms

Slabs

Pipe Making (seam pipe)

• Both skelp and billets are used to make pipes. Skelp is made into welded pipe.

• In first steel (skelp) is heated.• The steel is then passed through a series of grooved rollers.• As it passes by, the rollers cause the edges of the skelp to curl together.

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• The steel next passes by welding electrodes. These devices seal the two ends of the pipe together.

• Then passed through a high pressure roller which helps create a tight weld.

Pipe Making (seamless pipe)

• When seamless pipe is needed, square billets are used for production. They are heated and molded to form a cylinder shape, also called a round.

• The round is then put in a furnace where it is heated white-hot, then is rolled in high pressure and results hole is form in the center.

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• Since this hole is irregularly shaped, a bullet shaped piercer point is pushed through the middle of the billet as it is being rolled.

• After that the pipe may still be of irregular thickness and shape. To correct this it is passed through another series of rolling mills.

Quality Control

• To ensure steel pipe meets specifications. For example, x-ray gauges are used to regulate the thickness of the steel pipe.

• The gauges work by utilizing two x rays.1. One ray is directed at a steel of known thickness. 2. The other is directed at the passing steel on the

production line. • If there is any variance between the two rays, the

gauge will automatically trigger a re sizing of the rollers to compensate.

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• One method of testing a pipe is by using a special machine. This machine fills the pipe with water and then increases the pressure to see if it holds.