Difference between tube and pipe

It is generally thought that plastic tube and plastic pipe are the same thing. These words are often used interchangeably, because tubes and pipes are both long hollow cylinders. But they are actually quite different. In this blog we explain the difference between tube and pipe..

What is a plastic tube?

Plastic tube is a long hollow cylinder that is defined by its outside diameter (OD). The size of the bore, which is the hollow area in the middle of the tube, isn’t critical to the end use, whereas the OD is the most important measurement.

Within this definition, plastic tube is not suitable for transporting liquids and gases or for applications involving pressure. For such applications plastic pipe is more suitable. Tubing is more commonly used for general purpose applications such as modelling, crafts, packaging, flags, conduit, display applications, and the construction of simple frames and structures.

What is a plastic pipe?

Plastic pipe is a long hollow cylinder that is defined by its internal diameter (ID). The size of the bore, which is the hollow area in the middle of the tube, is usually critical to the intended use of the pipe. So the ID is the more important measurement in the mind of the buyer.

Plastic pipe is commonly used for transporting liquids or other substances including gases. Therefore factors that need to be considered are compatibility with chemicals, heat tolerances and the measurement of pressure within the pipe system.

What is the difference between tubing and pipes?

There is an important but often misunderstood difference between tube and pipe. The difference is essentially how the hollow cylinders are manufactured and measured.

For pipes, the inside diameter (ID) matters a great deal because that determines the capacity of the pipe. Conversely, for tubes the outside diameter (OD) is more important and is usually the measurement that is the deciding factor.
This leads to the question of why can’t both the ID and OD be defined? The manufacturing process plays an important prole in answering this. It is possible to have a consistent bore, which is the ID. And it is possible to have a consistent OD. But during the extrusion process the wall thickness varies, and the manufacturer can either control the ID or OD. But not both, or at least not to a high precision.

Pipe and tube are two words for hollow cylinders, but they are not the same. In simple terms, pipe uses the inside and tube uses the outside.

Where can I buy plastic pipe in the UK?

If you require plastic pipe rather than plastic tube then we recommend you contact a pipe specialist. There are many companies in the UK which specialise in pipes which can easily be found by doing a Google search. Many plastic pipe stockists specialise in pressure pipework and drainage, there are a wide range of different brands and materials.

PVC tube - is it always round

Plastic tubes are often, but not always, made from PVC. Athough PVC tubes are most often thought of as being round, this is not always the case. Square and rectangular tubes are also widely used and the shape of the tube will depend on the required purpose of your project. Plastic tubing has a central hollow area which is enclosed within a surrounding wall. This surrounding wall can be round, square or rectangular.

Where can I buy plastic tube

At MKM Extrusions we have a range of round rigid tubing available on our online shop. There are two measurements of importance, the outside diameter (OD) and the wall thickness. It is important to note that the internal diameter (ID) is not specified.

Plastic tube is generally smaller in size than plastic pipes. The smallest rigid round tube we offer has an outside diameter of 7mm, with the largest being 50mm. Wall thicknesses range from 1mm to 3mm. All our plastic tubing is available is either white or black.

Our stock range of plastic tubing is sold in packs of 75 metres. For rigid round tubes there are 25 x 3 metre lengths in each pack. For our range of flexible tube there are 3 x 25 metre coils in each pack. Free samples are available on request, just get in touch and let us know the products you are interested in. We will then post you short samples by Royal Mail.