A tube, or tubing, is a long hollow cylinder used for moving

fluid In physics, a fluid is a liquid, gas, or other material that continuously deforms (''flows'') under an applied shear stress, or external force. They have zero shear modulus, or, in simpler terms, are substances which cannot resist any shear ...

s (

liquid A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a (nearly) constant volume independent of pressure. As such, it is one of the four fundamental states of matter (the others being solid, gas, ...

s or gases) or to protect electrical or optical cables and wires. The terms "

pipe Pipe(s), PIPE(S) or piping may refer to: Objects * Pipe (fluid conveyance), a hollow cylinder following certain dimension rules ** Piping, the use of pipes in industry * Smoking pipe ** Tobacco pipe * Half-pipe and quarter pipe, semi-circular ...

" and "tube" are almost interchangeable, although minor distinctions exist — generally, a tube has tighter engineering requirements than a pipe. Both pipe and tube imply a level of rigidity and permanence, whereas a

hose A hose is a flexible hollow tube designed to carry fluids from one location to another. Hoses are also sometimes called '' pipes'' (the word ''pipe'' usually refers to a rigid tube, whereas a hose is usually a flexible one), or more generally ...

is usually portable and flexible. A tube and pipe may be specified by standard pipe size designations, ''e.g.'', nominal pipe size, or by nominal outside or inside diameter and/or wall thickness. The actual dimensions of pipe are usually not the nominal dimensions: A 1-inch pipe will not actually measure 1 inch in either outside or inside diameter, whereas many types of tubing are specified by actual inside diameter, outside diameter, or wall thickness.

Manufacture

There are three classes of manufactured tubing: seamless, as-welded or electric resistant welded (ERW), and drawn-over-mandrel (DOM). * Seamless tubing is produced via

extrusion Extrusion is a process used to create objects of a fixed cross-sectional profile by pushing material through a die of the desired cross-section. Its two main advantages over other manufacturing processes are its ability to create very complex c ...

or rotary piercing. * Drawn-over-mandrel tubing is made from cold-drawn electrical-resistance-welded tube that is drawn through a die and over a mandrel to create such characteristics as dependable weld integrity, dimensional accuracy, and an excellent surface finish.

Standards

There are many industry and government standards for pipe and tubing. Many standards exist for tube manufacture; some of the most common are as follows: *

ASTM ASTM International, formerly known as American Society for Testing and Materials, is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, an ...

A213 Standard Specification for Seamless Ferritic and Austenitic Alloy-Steel Boiler, Superheater, Heat-Exchanger Tubes. *ASTM A269 Standard Specification for Seamless and Welded Austenitic Stainless Steel Tubing for General Service *ASTM A270 Standard Specification for Seamless and Welded Austenitic Stainless Steel Sanitary Tubing *ASTM A511 Standard Specification for Seamless Stainless Steel Mechanical Tubing *ASTM A513 Standard Specification for Electric-Resistance-Welded Carbon and Alloy Steel Mechanical Tubing *ASTM A554 Standard Specification for Welded Stainless Steel Mechanical Tubing *

British Standard British Standards (BS) are the standards produced by the BSI Group which is incorporated under a royal charter and which is formally designated as the national standards body (NSB) for the UK. The BSI Group produces British Standards under the ...

1387:1985 Specification for screwed and socketed steel tubes and tubulars and for plain end steel tubes suitable for welding or for screwing to BS 21 pipe threads ASTM material specifications generally cover a variety of grades or types that indicate a specific material composition. Some of the most commonly used are: *TP 304 *TP 316 *MT 304 *MT 403 *MT 506 In installations using

hydrogen Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-to ...

, copper and stainless steel tubing must be factory pre-cleaned (ASTM B 280) and/or certified as instrument grade. This is due to hydrogen's particular propensities: to explode in the presence of

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements ...

, oxygenation sources, or contaminants; to leak due to its atomic size; and to cause embrittlement of metals, particularly under pressure.

Calculation of strength

For a tube of

silicone rubber Silicone rubber is an elastomer (rubber-like material) composed of silicone—itself a polymer—containing silicon together with carbon, hydrogen, and oxygen. Silicone rubbers are widely used in industry, and there are multiple formulation ...

100607 ami.ac.uk with a tensile strength of 10 MPa and an 8 mm outside diameter and 2 mm thick walls. The maximum pressure may be calculated as follows: : Outside diameter = : Wall thickness = :

Tensile strength Ultimate tensile strength (UTS), often shortened to tensile strength (TS), ultimate strength, or F_\text within equations, is the maximum stress that a material can withstand while being stretched or pulled before breaking. In brittle materials ...

= 10 * 1000000 [ Pa] : Bursting pressure = (Tensile strength * Wall thickness * 2 / (10 * Outside diameter) ) * 10 [Pa] Gives bursting pressure of 5 MPa. Using a safety factor: :Pressure max = (Tensile strength * Wall thickness * 2 / (10 * Outer diameter) ) * 10 / Safety_factor [Pa] 33

References

External links

Steeltubeinstitute.org
Piping

Manufacture

Standards

Calculation of strength

See also

References

External links