Confusing pipe elbow radius
Confusing pipe elbow radius
(OP)
I just got a tender where i among others ordered some pipe elbows. On the pipe elbows it said 3D and i thought, "hmm that must be wrong because i want 1,5D bends (1,5 times the diameter)". However now that I've done some googling I realized that the pipe standard (ISO 5151) says that 3D elbows has a 1,5D bend (1,5 times the diameter), and a 5D elbow has a 3D bend (3 times the diameter).... Why in the world does someone name the pipe elbows to 3D and 5D when it is so easily confused with the radius of the pipe...
So my question is what does the name 3D and 5D refer to?
So my question is what does the name 3D and 5D refer to?





RE: Confusing pipe elbow radius
http://www.crp.co.uk/UserFiles/Documents/Dimension...
RE: Confusing pipe elbow radius
When you go to SI it isn't quite so pretty since the SI equivalent of "nominal" is "DN" which rounds the conversion from inches to mm to 25 instead of 25.4. This means that a 10-inch (250 DN) short radius elbow has a dimension of 15 inches [381 mm] from center on one leg to the face of the other leg instead of 375 mm.
ASME B16.5 further complicates this by listing distances for flanged fittings instead of the raw fitting without flanges welded on. The information is all there, but it can be a challenge to dig out.
David Simpson, PE
MuleShoe Engineering
In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist
RE: Confusing pipe elbow radius
If you look at the dimension table that robyengIT posted is says that a DN50/2" 3D elbow has a radius of 152mm (3 times the radius).
But if you look at this:
http://www.sagarfitting.com/buttweld-fitting-fitti...
There it says that a DN50/2" 3D elbow has a radius of 76mm (1,5 times the radius).
And if you look at this:
http://www.bendtechgroup.com.au/images/downloads/d...
There, on page 5, they call a DN50 elbow with 76mm radius 1,5D
I figure that the most "right way" is the 2nd link where a DN50 3D elbow has a 76mm radius. But what does the name 3D come from, that is my question. What does the "3" and the "D" in 3D refer to?
RE: Confusing pipe elbow radius
David Simpson, PE
MuleShoe Engineering
In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist
RE: Confusing pipe elbow radius
RE: Confusing pipe elbow radius
The sagar site says 3D elbow is 152mm
Your post makes no sense I'm afraid. 3D means 3 D median radius.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Confusing pipe elbow radius
Although the words bends and elbows are often used as synonyms, there are some differences. Bend is a term for any offset of direction in the piping while elbow is an engineering term. Elbows have limitations to angle, bend radius and size. Most angles are either 45 degrees or 90 degrees. All other offsets are specifically pipe bends. And while elbows have sharp corners, bends never do. The most basic different between a bend and an elbow is the radius of curvature. Bends have a radius more than twice the diameter, and elbows have a radius of curvature between one and two times the size of the pipe’s diameter. All elbows are bends, but not all bends are elbows.
http://www.benditinc.com/uncategorized/9-facts-abo...