| Revision as of 13:08, 20 April 2014 editHohum (talk | contribs)Extended confirmed users, Pending changes reviewers68,470 edits →See also← Previous edit | Revision as of 16:42, 17 May 2014 edit undoJohn of Reading (talk | contribs)Autopatrolled, Extended confirmed users, Pending changes reviewers766,024 editsm Typo/general fixing, replaced: a 8 → an 8 using AWBNext edit → | ||
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| {{For|structural tubing|Hollow structural section}} | {{For|structural tubing|Hollow structural section}} | ||
| ⚫ | ] plastic tubing for use as a conduit for electric wires]] | ||
| {{Refimprove|date=July 2008}} | {{Refimprove|date=July 2008}} | ||
| ⚫ | ] plastic tubing for use as a conduit for electric wires]] | ||
| A '''tube''', or '''tubing''', is a long hollow cylinder used for moving ]s (]s or ]es) or to protect electrical or optical cables and wires. |
A '''tube''', or '''tubing''', is a long hollow cylinder used for moving ]s (]s or ]es) or to protect electrical or optical cables and wires. | ||
| The terms "]" 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 ] is usually portable and flexible. A tube and pipe may be specified by standard pipe size designations, ''e.g.'', nominal pipe size, or by ] 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. | The terms "]" 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 ] is usually portable and flexible. A tube and pipe may be specified by standard pipe size designations, ''e.g.'', nominal pipe size, or by ] 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. | ||
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| ==Calculation of strength== | ==Calculation of strength== | ||
| For a tube of ]<ref name="ami-prop">{{cite web|title=Mechanical properties of metals|url=http://www.ami.ac.uk/courses/topics/0123_mpm/index.html}} 100607 ami.ac.uk</ref> with a tensile strength of 10 MPa and |
For a tube of ]<ref name="ami-prop">{{cite web|title=Mechanical properties of metals|url=http://www.ami.ac.uk/courses/topics/0123_mpm/index.html}} 100607 ami.ac.uk</ref> with a tensile strength of 10 MPa and an 8 mm outer diameter and 2 mm thick walls. The maximum pressure may be calculated as follows: | ||
| :] = 0.008 []] | :] = 0.008 []] | ||
Revision as of 16:42, 17 May 2014
For structural tubing, see Hollow structural section. | This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Tube" fluid conveyance – news · newspapers · books · scholar · JSTOR (July 2008) (Learn how and when to remove this message) |
A tube, or tubing, is a long hollow cylinder used for moving fluids (liquids or gases) or to protect electrical or optical cables and wires.
The terms "pipe" 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 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
Main article: Tube drawingThere 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 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 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 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, 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, 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 with a tensile strength of 10 MPa and an 8 mm outer diameter and 2 mm thick walls. The maximum pressure may be calculated as follows:
- Outer diameter = 0.008 [meter]
- Wall thickness = 0.002 [meter]
- Tensile strength = 10 * 1000000 [Pa]
- Pressure burst = (Tensile strength * Wall thickness * 2 / (10 * Outer diameter) ) * 10 [Pa]
Gives burst pressure of 5 MPa.
Using a safety factor:
- Pressure max = (Tensile strength * Wall thickness * 2 / (10 * Outer diameter) ) * 10 / Safety_factor [Pa]
See also
References
- "Mechanical properties of metals". 100607 ami.ac.uk