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Have we bent the bend?
2

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?

I agree. I am used to hearing "A 180° pipe bend" or a "pipe with a 180° bend", etc.

RE: Have we bent the bend?

Did the context go "have pipe bent to 180 deg"?  Then I can see the use of the word.  I’m not a fluids guy or plumber, but for the case of 180 deg wouldn’t you want to give the bend radius instead of the angle?  I’m picturing a “U” shape pipe.

Go Mechanical Engineering
Tobalcane

RE: Have we bent the bend?

(OP)
No, Tobalcane,
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?

I just looked up the word “bent” and the meaning is: altered from an original straight condition.  The word “bend” means: change direction.

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…

Go Mechanical Engineering
Tobalcane

RE: Have we bent the bend?

The only time I've ever heard "bent" used as a noun is in the context of a support for beams (like a pier cap).  I think it's just an error.  Was it a non-native English speaker who did the detailing?

Hg

RE: Have we bent the bend?

(OP)
HgTX

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?

(OP)
hm ...throughout...

Putting Human Factor Back in Engineering

RE: Have we bent the bend?

I think that the bend/bent thing is just someone trying to put some human factor back in engineering...

RE: Have we bent the bend?

(OP)
"Aren't I popular?" - Ace Ventura 2 [Nature Calls]

Putting Human Factor Back in Engineering

RE: Have we bent the bend?

Pipe with 0 degree bend = straight.

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?

Been drinking again, Julep?  

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?

(OP)
And how about a pipe bend bent 360°?

Putting Human Factor Back in Engineering

RE: Have we bent the bend?

That would be to shut off the water if the valve is stuck.
hee hee

RE: Have we bent the bend?

Skog,

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?

(OP)
MintJulep

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?

MintJulep

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?

Surely bent is past tense. How can someone describe correctly a bend as bent when it hasn't happened?

RE: Have we bent the bend?

Unless it is ex-stock, rather than a site bend, in which it already exists.

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?

As long as we get the point across and it is written clear, in reality it doesn't matter.

RE: Have we bent the bend?

VeryPickey,

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 think of the degrees not as the angle made by the intersection, but as degrees of arc swept out by the curved part of the pipe (assuming a circular curve).

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?

Reminds me of an old "BC" comic.

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?

Calm down, Julep & Picky - you're both right

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?

skogsgurra says: "I think that the bend/bent thing is just someone trying
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?

(OP)
schetwynd
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?

"he who writes the specifications makes the definitions"

RE: Have we bent the bend?

There are 360° around the arc of a circle.  That's how a 180° pipe bend is measured, not by intersecting lines.  I also have experience with pipe bents, a row of which make up a pipe alley.

Larry

RE: Have we bent the bend?

a pipe can be bent, once it is bent it will have a bend in it. you can bend a pipe then it will be bent.if you put a bend in it you bent it . to describe the angle would be to describe the bend .or you can describe the angle you want it bent to.they are all nouns and verbs,adjectives and adverbs.we need to look more at the words in the context,not the word itself.

RE: Have we bent the bend?

Can we talk about sprung springs now?

"I think there is a world market for maybe five computers."
Thomas Watson, chairman of IBM, 1943.
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?

RE: Have we bent the bend?

Then "Hope springs eternal" in the past tense must be "Hope sprung eternal"?  Oh, wait, how can you have the past tense of eternity?

RE: Have we bent the bend?

"Hope sprang eternal, or at least it thought it did..."

RE: Have we bent the bend?

In non-Euclidean geometries parallel lines meet, sometimes more than once.

RE: Have we bent the bend?

Space is curved or so says The big E and HgTX must be right when he said "Hope sprang eternal, or at least it thought it did..." 'cause it was also said, "...before Abraham was, I am."


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