What are they, actually.....

Monday, June 29, 2009

Many people realize for something just by see it, touch it, or just heard from someone else. They can describe it only by what they have known. Let us talk about pipe. With this method in understanding, it can be various opinion in determining the pipe, since every people have their own imagination.

It's important to refer from something that already agreed to be used universally.Based on ASME B31.1-2007, "pipe is a tube with round cross section conforming to the dimensional requirements for nominal pipe size". Regarding with pipe size, you can see it in ASME B36.10M table 1 and ASME B36.19M table 1. There are some discrepancies between pipe and tube, such as tubes are specified by its outside diameter, meanwhile pipes by its nominal diameter. Pipes are used to transport any fluids, meanwhile tubes are used in a process industry or plant, mostly. Therefore, there is a finned tube to have an expanded area in heat transfering.
Pipes are produced up to large diameter, meanwhile tubes are produced in a small bore. Range of size for pipes are from 1/2" up to 60", meanwhile tubes are from 1/2" up to 8".
Generally there are two kinds of pipe, based on how they're manufactured. The first type is a seamless pipe, and the other is a seam pipe or welded pipe.Welded pipe itself, consist of longitudinal seam pipe and spiral welded pipe.
Seamless pipe mean that there is not any welding process in manufacturing the pipe, the pipe are produced from a hot round solid steel billet. A steel round bar then penetrated to the hot round solid steel billet, make it expand become a seamless pipe.
Welded pipes are produced from a plain plate which rolled and then welded on the edge of joint.
Pipe are specified in based on its material, wall thickness, and its nominal diameter. Some example for carbon steel material for pipe are as follow :

* A-53 Gr.A and Gr.B is the standard material defined by ASTM for both of seamless pipe and welded pipe.
* A-106 Gr.A and Gr.B, produced for seamless pipe.
* A-333 Gr.1, this one used for working temperature under 1 degree Celcius or minus 50 degree Fahrenheit.
* A-335-P1, categorized to alloy pipe. Used to working temperature between 414 to 468 deg Celcius or between 776 to 875 deg Fahrenheit.
* A-335-P22, also categorized to alloy pipe, with range of working temperature between 539 to 593 deg Celcius or equal with 1001 to 1100 deg Fahrenheit. Ussualy, used as transition material between high alloy(P91) to carbon steel.

There are still other materials specification those cann't be mentioned in this article. But if you curious to learn more, you can find them in ASME IID.