How to find Center to End on a 90 degree elbow ASME B16.3-2011 1

[jose0908]

I have a question. What tools do you use to find the center to end dimension on a 1/2" threaded 90 degree mallable iron fitting, and the correct way to obtain the accurate dimension? Can it be done with a dial caliper? Thanks for the advise in advance.

 

[XL83NL]

I have the 2006 edt of B16.3 in front of me, but the dimensions are just displayed in the standard.
If you mean measuring in real life; go out to your workshop guys,it not difficult to measure.
Im sure they can help you with this, but I do this usually with a standard flexibel steel rule or piece of measuring tape.

 

[jose0908]

XL83NL yes, I see the drawing, I'm trying to be technical with a 12" dial caliper. I start measuring from one end of the 90, but how exactly do I find the center, being that the area where the exact center is, is round.

 

[MikeHalloran]

You could have a measuring plug made up, with an external pipe thread on one end, and a center drilled recess, or a punch mark on the other end. Don't forget wrenching flats so you can get it out.

... but that's gross overkill, really, and it's still awkward to use with a caliper, unless you add a sliding square leg, but that's really overkill.

A framing square and a tape measure should be sufficient for any reasonable purpose except manufacturer inspection.



Mike Halloran
Pembroke Pines, FL, USA

 

[MintJulep]

Considering that a 1/2" fitting is not all that large an appropriately sized caliper will work just fine.

I would measure the overall length and the OD of an end and do a bit of simple arithmetic.

If by "center" you mean the center of one of the holes then a bit more measurement and arithmetic is needed to see if the hole is in the middle of the casting.

 

[jose0908]

Thanks for the advise everyone. Eng-tips is a great website and offer great help thru people like you guys. Thanks again.

 

[capnhook]

1.) Take the part to a 3-d scanner, make an .stl file.

2.) Run the .stl file through some $$software that fixes gaps and orients all the triangle vectors out from the center of the mass.

3.) Go to the $$stereolithography lab and get a part made to check against your real part.

4.) Get two parts made so that you can start a $$six-sigma study of the minute differences between them.

5.) Get a third part made in case you drop one of the other two.

6.) If you drop one of the two, re-start your $$six-sigma study.

7.) Bring it into your cad $$system with an $$.stl translator you paid too much $$ for.

8.) Orient the data to a grid of XYZ planes, and extract the rough profile curves.

9.) Create smoother curves from the rough profile curves.

10.) Construct surfaces using the smoother curves you made.

11.) Trim all surfaces to each other, so that your new model is watertight.

12.) Sew all these surfaces together into a real solid model.

13.) Make a pretty $$cartoon for everybody, using your $$cad system. Use the dimensioning tools. Don't forget to $$tolerance the dimension to four decimal places (six for metric).

14.) $$Print it out on a $$color printer so everybody will marvel at your great work.

15.) $$Publish your $$six-sigma report, and suggest better ways to accomplish this task the next time it needs repeated.


Or use some calipers.





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[green]To the Toolmaker, your nice little cartoon drawing of your glass looks cool, but your solid model sucks. Do you want me to fix it, or are you going to take all week to get it back to me so I can get some work done?[/green]