Have we bent the bend?
Have we bent the bend?
(OP)
I just read a specification calling a 180° bent piece of pipe a pipe "bent". I disagree with that and say "pipe bend" is a correct name. What do you think?
Putting Human Factor Back in Engineering





RE: Have we bent the bend?
RE: Have we bent the bend?
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Tobalcane
RE: Have we bent the bend?
the spec uses expression "bending radius of each bent", "180° bents", "small bents", and so forth.
Putting Human Factor Back in Engineering
RE: Have we bent the bend?
If the practice is to take straight pipes and alter them to a new form than I can see the word bent being used. If the pipes are already formed and then formed again, then the word bend would be probably used. But, drafting practice will always supersede and I think “bend” is the word that they use.
Just an observation…
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Tobalcane
RE: Have we bent the bend?
Hg
RE: Have we bent the bend?
I think it is an error but it is used thruough the spec. The spec was a multicultural team effort inclusive of native and non-native english speakers.
Putting Human Factor Back in Engineering
RE: Have we bent the bend?
Putting Human Factor Back in Engineering
RE: Have we bent the bend?
RE: Have we bent the bend?
Putting Human Factor Back in Engineering
RE: Have we bent the bend?
Pipe with 45 degree bend = Draw a line coincedint with the center-line of the portion of the pipe "upstream" of the bend. Draw a similar line for the "downstream" section of pipe. These two lines will intersect within the walls of the pipe. Extend the first line. The angle between the first and second line = 45 degrees.
Similar excercise for 90 degrees, or many any other angle, up to 179.999999999 degrees.
However, for a "U" shaped bend, the lines are parallel. They do not intersect. There is no measureable angle.
So, I would say that "180 degree bend" has no physically possible interpretation.
Need to call it a "U" bend, and define the radius of the bend and necessary parallelarity of the "in" and "out" legs, otherwise there is no way to inspect it.
RE: Have we bent the bend?
Lines do not have to intersect to form an angle - sailors find angles on charts using parallel transportation. Or whatever it's called in English.
RE: Have we bent the bend?
Putting Human Factor Back in Engineering
RE: Have we bent the bend?
RE: Have we bent the bend?
From Princeton.edu:
"angle: the space between two lines or planes that intersect; the inclination of one line to another; measured in degrees or radians "
Of course lines have to intersect to form an angle. I will conceed that line segments may be extended to their intersection point to obtain the angle between them.
There is no angle between two parallel lines.
RE: Have we bent the bend?
I dare to disagree.
I still remember my school years and quite clearly recall angles measured in ° with no limit put on values.
According to that it is possible to have an angle measuring 180° or even 360° and it does not take too much imagination to figure out that it is possible to measure the angle between the parallel lines.
The case may be extreme but still not too abstract to exist.
Putting Human Factor Back in Engineering
RE: Have we bent the bend?
If you stick the pipe in the bending machine then rotate the operating handle by 180° then you have a pipe with a 180° bend.
Likewise a ship sailing north east on a heading of 45° makes a 180° turn and is then sailing south west on a heading of 135°
Jeff
RE: Have we bent the bend?
RE: Have we bent the bend?
I have also used bent as in pile bents being sets of piles for multispan bridge piers.
(Do none of us have anything better to do?)
StephenA
RE: Have we bent the bend?
RE: Have we bent the bend?
Yes, I agree, you can measure any angle. But where do you put the dot on the bottom of the protractor? There has to be an intersection.
I maintain that by definition, there can be no angle between parallel lines.
Nonats,
Yes, we all "know" what a pipe with a "180 degree bend" looks like. We are just so used to the colloquiallism, we never stop to think about it from fundamental geometric definitions.
Course bearings are not quite the same as plane angles.
If your ship makes a "U" turn, such that it is travelling on a reciprical heading, but parallel to the original track, it will not return to the same point that it started. In order to return to the same point, it needs to make a "P" shapped turn.
RE: Have we bent the bend?
I have to say I have *never* thought of applying a protractor to an imaginary point of intersection of imaginary pipe axes.
Hg
RE: Have we bent the bend?
BC set off dragging a forked stick across the ground to prove that parallel lines never meet. After walking across the desert all the way to the last panel of the comic, the stick had worn down to the fork and the lines did meet.
Jeff
RE: Have we bent the bend?
Degrees are used to define an angle in the intersection of two radii. A 180 degree angle doesn't make sense in the pipe-bending context. One point to Julep - but Picky didn't use the word 'angle' in his question.
Degrees are also used for relative direction. So a sailor / aviator can do a 90 or a 180 or a 540 and he doesn't have to follow a radius, or intersect his original path - just rotate (yaw) through that angle. One all.
The original question - bent is not a noun (unless it's a type of reed or grass, or if it's a tendency /preference / inclination).
Personally, I have a mechanical bent (scope for rude joke starts now).
John
John
RE: Have we bent the bend?
to put some human factor back in engineering..."
Your statement sounds kind of stupid to a logical thinker, but you just may be right - people are silly enough and easily distracted enough to think that "bent" is more human - warmer and friendlier? - than "bend," if the word(s) are introduced in a way to imply this. The whole concept is pointless - some words have such connotations, but "bent" and "bend" are not included with these. There are folks out there who try to improve the language by using other words to replace those that have worked just fine for a zillion years to describe what they describe - these folks don't have enough to do.
I've never seen "bent" used as a noun in describing "bends" or tees or other fittings, and I qualify as a first-class journeyman pipefitter, so I've run across a few fittings in my day.
I've seen "bent," as a noun, used to mean an inclination to a certain skill - "He has a bent for wood working."
Of course, it could just be that someone unfamiliar with the field was assigned to write this technical document, with either no professional of whom to ask questions, or without the intellectual wherewithal to ask.
RE: Have we bent the bend?
I read your posting with a lot of interest. I like your thoughts on "human factor". However my guess is: in this context skoksgurra was refering to my signature and his comment was purely personal, which is another evidence of human factor being applied.
Putting Human Factor Back in Engineering
RE: Have we bent the bend?
RE: Have we bent the bend?
Larry
RE: Have we bent the bend?
RE: Have we bent the bend?
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RE: Have we bent the bend?
RE: Have we bent the bend?
RE: Have we bent the bend?
RE: Have we bent the bend?