Q. How to model a semi circular header in AutoPIPE?

Applies To
Date Logged
& Current Version
Oct. 2018


how to model a semi circular ring main with the following configuration?

(Top view of semi circular ring main, each circle represents a pipe connected perpendicular to the ring main piping)


In this example, the ring main will be created off to the side and then copied / pasted into position. 

Step 1. At any location, insert an anchor

Step 2: The ring main will be on Laying on the X-Z plane, insert a temporary pipe of any length (ex, 3 feet) in the X=axis direction 

Step 3: Start the Ring Main wizard

Enter the following:

a. Offset from point = A01 (current node point)

b. Ring orientation = 90 deg (see image at bottom of dialog to help with orientation, use 90 deg to lay ring on X-Z plane)

c. Create new segment = Enable checkbox (to make it easier to copy/paste later)

d. Radius = 203.5 (can be any value but in this example the semi circular ring radius = 16' 11.5")

e. DX = 203.5 (specify exact direction of radius)

f. Branch type = Run (enable check box), 

g. Pipe Identifier = 12 ( select current pipe id for your model, in this example Pipe Id = 12 was used).

Press NEXT button 

Step 4: 

a. click on the word Custom Angles

b. Enter the angles as shown in the drawing above

c. Header length = 3 inches or 0.25 feet

Press Finish to insert the ring main. 


1. In this modeling approach, node points A00 - A01 - B01 were uses as construction aids and will now be removed. 

2. Use Copy / Paste / Rotate / Move commands as needed to get ring main into the proper location / orientation.

3. Use Convert Run to Tee command as needed to model connection points or model runs to center of 3 inch header node points provided in step 4 above.

4. Yes, AutoPIPE could have automatically create all the vertical connected pipe, In step #3: 

 a.  Update Branch type = Tee (enable check box),

 b. Branch Tee Offset: DY = 1 ft

Using either approach, the user can continue modeling branch piping from header, or connect existing piping to ring main as required.  

See Also

Bentley AutoPIPE