the Different between Pipe Bend and Elbow 2

[1044B]

What is a consideration of pointing out the pipe bend or elbow on tie in spool.
I found some of design use pipe bend and the other use elbow.

 

[LHA]

I don't know what a "tie in spool" is, but I have always found the terms "elbow" and "bend" used interchangeably.

However, I have noticed that prefabricated, off-the-shelf fittings (90d, 45d, 22.5) tend to be called elbows, although I have seen them called bends.

I have also noticed that custom fittings - such as those for HDPE storm pipes - tend to be called bends. I can't recall having seen them called elbows.

Maybe that is the difference.

Remember: The Chinese ideogram for “crisis” is comprised of the characters for “danger” and “opportunity.”
-Steve

 

[rconner]

I think most would probably agree all fittings that just change the direction of pipelines could be called "bends", of one sort or another.
I guess some of these folks might refer specifically to 90 degree bends as "el(l)s" (they look like an "L"?) or "elbows"; whereas, a few other folks might even call all angle bends including 90 degree "elbows". Incidentally, I have heard in effect special 180 degree bends also called "return" bends in the past, for perhaps obvious reasons.
I'm not sure where all formal authorities lie on all this, but I believe at least some ISO and ANSI/AWWA specifications, at least for water pipe fittings, prefer specifying the specific degree angle and then only the term perhaps least likely to be confused (i.e. "bend"). Thus, a 90 degree "ell" (perhaps to some) becomes per the standard a "90 (degree) bend", and I'll bet most get the fitting then they want with this standard convention!

 

[1969grad]

An elbow is a standard fitting per ASME B16.9 and has a radius of 1D or 1.5D.

A bend is a custom fabricated item usually by the induction process per ASME B16.49 and has a radius greater than an elbow.

Typically bends are used on pig launcher/receivers where a bend radius of 5D is required.

Other applications are pipelines requiring a turn too tight to be done in the field with the bending machine.

Obviously, the elbow is a standard fitting and is cheaper than a bend which is a custom fabricated item.

Considerations to be taken into account on a drawing is the geometry of the bend which usually has tangents at the ends.

 

[Shmulik]

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