Author Topic: How Y-Size of Coupling is Calculated?  (Read 283 times)

0 Members and 1 Guest are viewing this topic.

Offline jaysomlamTopic starter

  • Senior Member
  • ****
  • Posts: 486
  • Country: us
  • Gender: Male
How Y-Size of Coupling is Calculated?
« on: Jan 20, 2025, 18:11:35 PM »
We are trying to use CAMduct to fabricate Couping.  But we have a hard time setting up Coupling to get the correct Y-Size.

Here, we use 10" diameter of Coupling with male connectors (Sex Type is Female) as an example.  Our shop expects the Y-Size of this Coupling to be 32.023".  But CAMduct shows that its Y-Size is 32.10994".  We want to adjust its to get its Y-Size to be as close to 32.023" as possible.  But that is where I cannot find a way to do.

The following is the details of this Coupling with male connectors:
1.  10" diameter.
2.  Male connector has -0.125" Diameter Adjustment.
3.  The seam has 0.5" Male Allowance and 0.5" Female Allowance.

I do this to calculate the circumstance:
  ( Diameter + Diameter_Adjustment ) * Pi
And that is:
   ( 10" - 0.125" ) * 3.1416 = 31.023"
And the Y-Size should be:
   Circumference + Male Seam Allowance + Female Seam Allowance
And that is:
   31.023" + 0.5" + 0.5" = 32.023"
And that is how our shop expects the Y-Size to be.

But CAMduct comes up with 32.10994".  It is 0.0867" more than what we have expected.  Please see the attached picture to see the Y-Size that CAMduct comes up with.  Please also note that this 0.0867" difference remains unchanged when I increase the diameter.  Seem like somewhere in CAMduct or in our Fabrication Database adds 0.0867" to Y-Size for coupling.

Please let me know how CAMduct calculates the Y-Size.  Then I can adjust the settings accordingly to get the correct Y-Size.  Thanks.

Jaysam

Offline PipeFitter72

  • Full Member
  • ***
  • Posts: 186
  • Country: us
  • Gender: Male
Re: How Y-Size of Coupling is Calculated?
« Reply #1 on: Jan 23, 2025, 16:22:19 PM »
When you make one does it fit correctly?
Union CADD Database Administrator

Offline jaysomlamTopic starter

  • Senior Member
  • ****
  • Posts: 486
  • Country: us
  • Gender: Male
Re: How Y-Size of Coupling is Calculated?
« Reply #2 on: Jan 24, 2025, 12:53:29 PM »
The shop manager told me that this small difference will make a difference in term of fabrication and fitting.

Jaysom

Offline PipeFitter72

  • Full Member
  • ***
  • Posts: 186
  • Country: us
  • Gender: Male
Re: How Y-Size of Coupling is Calculated?
« Reply #3 on: Jan 24, 2025, 15:31:17 PM »
My only suggestion is to change the diameter adjust for the connector to make it what you want. No idea other than that.
Union CADD Database Administrator

Offline jaysomlamTopic starter

  • Senior Member
  • ****
  • Posts: 486
  • Country: us
  • Gender: Male
Re: How Y-Size of Coupling is Calculated?
« Reply #4 on: Jan 27, 2025, 16:29:46 PM »
Unfortunately changing the Diameter Adjust of the connector cannot remove the extra 0.0867" found in Y-Size of Coupling-Male.  We can see the result from the attached picture.  The Diameter Adjust only affects the calculation of the circumference.  Seem like that 0.0867" is added to the Y-Size _after_ the calculation of the circumference.  And I still don't know where that 0.0867" comes from.

0.0867" is less than 1/10".  I will have to convince the shop manager that the small 0.0867" is too small to make a difference.

Jaysom

Offline jaysomlamTopic starter

  • Senior Member
  • ****
  • Posts: 486
  • Country: us
  • Gender: Male
Re: How Y-Size of Coupling is Calculated?
« Reply #5 on: Jan 27, 2025, 16:51:41 PM »
Seem like I can work around this problem by assigning a small seam allowance.  This surely will work.

This won't actually fix the problem.  But a workaround is good enough for me.

Jaysom