Pipe (fluid conveyance)

A pipe is a long, hollow shape.

It helps things flow from one place to another. It can carry water or gas. It can even move tiny bits of powder.

People use pipes for many things. They carry water to our homes. They can also move oil.

Some pipes are made of metal. Others are made of plastic or clay. Long ago, people even used wood for pipes.

Some pipes are very strong. They can be used to build things like handrails.

Pipes are very useful tools for our world.

A pipe is a long, hollow shape.

It is a cylinder used to move things that flow. These things can be liquids like water. They can also be gases like air. Some pipes even move tiny bits of powder.

Pipes are used for many jobs. They carry water to our homes. They move oil and gas over long distances. Some pipes are used to build things. For example, they can make handrails or scaffolds.

Many materials can make a pipe. Metal pipes are often made of steel or iron. Copper is popular for water in homes.

Some pipes are made of plastic. Plastic is light and does not rust. In the past, people used wood or lead. We do not use lead for drinking water now. This is because lead can be toxic.

There are different ways to make pipes. Some are made by melting metal. Others are made by welding. Welding is a way to join pieces using heat. This creates a strong bond. This helps the pipe stay together.

A pipe is a hollow cylinder used to move things that flow. These flowing things are called fluids. Fluids can be liquids like water or gases like air.

Some pipes even move powders or small solids. Pipes are very useful for building things, too. A hollow pipe is much stiffer than a solid piece of the same weight. This makes them great for making handrails or support structures.

There are many ways to make a metal pipe. One way is called centrifugal casting. This uses hot, melted metal to form the shape. Another way is making seamless pipe. This is made by pulling a solid piece over a rod. This process is called rotary piercing.

Because there is no welding, these pipes are very strong. Other pipes are made by welding. This means rolling a metal plate and joining the edges with heat. This can be done with an electric current. The heat creates pools of molten metal that bind the pieces together.

People have used pipes for a very long time. The first known use was in Ancient Egypt. The Pyramid of Sahure had a temple with copper pipes for drainage.

Later, in 1817, Henry Osborne made a way to make iron musket barrels. Around 1820, he began making iron gas tubes. These were sold to a man named Samuel Clegg. In the 1800s, steel pipes were first made by using rivets. Later, people used H-shaped bars to clamp them. By the 1930s, most people switched to welding.

Many different materials can be used for pipes. Metal pipes are often made of steel or iron. Copper is very popular for water in homes.

Plastic is also common because it is light and does not rust. Plastic pipes include types like PVC and polyethylene. In the past, people used wood or lead. We do not use lead for drinking water today. This is because lead is toxic to humans.

Some large pipes are made of concrete or ceramic.

Understanding pipes helps us see how the world works. You might see pipes under the street in a city.

You might see them in a kitchen or a bathroom. They connect to other parts using fittings like elbows or tees. These parts help the pipe turn corners or split. Even the name "plumbing" comes from the Latin word for lead, which is called plumbum. Whether they carry water or gas, pipes are a vital part of our daily lives.

A pipe is a hollow, cylindrical section used to move substances that can flow. These substances are called fluids, which include both liquids and gases.

Beyond moving fluids, pipes can also transport slurries, powders, and small solids. Pipes are also useful in construction for structural applications. A hollow pipe is much stiffer per unit of weight than a solid rod. This makes them efficient for building supports or handrails.

In engineering, there is a specific difference between a pipe and a tube. A pipe is usually defined by a nominal diameter and a "schedule." The schedule tells you how thick the pipe walls are. A tube is often specified by its outside diameter (OD) and wall thickness. Tubes are often made to custom sizes with very precise tolerances. While the terms are often used interchangeably in daily life, they mean different things to professionals. In the United States, the word "tube" is used more often, while "pipe" is more common globally.

Metal pipes are manufactured using several distinct processes. One method is centrifugal casting, where hot, liquid metal is spun to form a shape. Another method creates seamless pipe, also known as SMLS. This is made through rotary piercing, where a solid billet is drawn over a piercing rod. Because seamless pipes have no joints, they are often seen as stronger and more reliable for high pressure.

Other pipes are made by welding. This involves rolling a metal plate and joining the edges together. One common method is Electric Resistance Welding (ERW). In ERW, an electric current passes through the edges to create heat. This heat forms pools of molten metal that merge the pieces into one solid seam.

Large-diameter pipes, those 16 inches or larger, use different technologies. Some are made using Submerged Arc Welding (SAW). There are two main types of SAW pipes: longitudinal (LSAW) and spiral (SSAW). LSAW pipes are made by bending and welding wide steel plates. They are often used in the oil and gas industry but are very expensive. SSAW pipes are made by welding steel coil in a spiral or helicoidal pattern. Because they use coils instead of plates, SSAW pipes are often cheaper. These large pipes are essential for moving massive amounts of resources across the world.

Humanity has used pipes for thousands of years. The earliest known use was in Ancient Egypt. The Pyramid of Sahure, built around the 25th century BC, featured a temple with copper drainage pipes.

In 1817, Henry Osborne developed a process for making iron musket barrels. By 1820, he began making iron gas tubes for pioneers like Samuel Clegg. In the 19th century, steel pipes were often held together with rivets or H-shaped bars. It was not until the early 1930s that welding became the standard method for making steel pipes.

Many materials are used to build pipes depending on the job. Metallic pipes are often made of steel, iron, or copper.

Copper is very popular for domestic water systems because it is great at transferring heat. Aluminum is used when weight is a concern. In the past, people used wood or lead for plumbing. The word "plumbing" actually comes from the Latin word for lead, *plumbum*. However, lead is toxic and is no longer allowed for new drinking water systems. In the US, it is estimated that 6.5 million lead service lines from before the 1930s are still in use.

Plastic is now a very common material for pipes. It is lightweight, does not rust, and is easy to connect. Common types include PVC (polyvinyl chloride) and polyethylene. Plastic is often used for buried municipal water lines. For low-pressure needs like sewage or storm water, engineers often use concrete or ceramic. These materials are heavy and durable. By choosing the right material and manufacturing method, engineers can ensure that water, gas, and even food powders move safely from one place to another.