07. How to model a Y-pipe fitting?

Applies To
Environment: N/A
Area: Modeling
Original Author:Bentley Technical Support Group
Date Logged
& Current Version
Jan 2015


How to model a Y-pipe fitting?


 See the following procedure:

1. On a straight run of pipe model to the Center point of the Y-connection (ex. A03).

2. Insert Run node point to next node point at the correct angle for the Right side Branch (ex 5 feet, Theta =135 deg to +X-axis. to node point A04).

3. Re-select node point A03, convert it to a Tee (Modify> Convert Point to> Tee> command).

4. Afterwards, select node point A04, using the keyboard arrow keys, press the left arrow key once, this will move the active node to A03. Indicated in the lower Left of the AutoPIPE screen.

Press the Up Keyboard Arrow key one time, A03 should still be the active node point however the active segment is *B*:

At this point, insert a new Pipe Run to next node point at the correct angle for the Left side Branch (ex Dx= -3.54 ft and Dy = -3.54 ft to node point B01).

5. SIF consideration:

At this time, review the model Consistency check report, the following will be displayed:

W726-173:The tee at following point(s) has header legs that are not straight and/or
the header and branch legs are not normal.

Most of the Piping Codes do not support or have calculations for Y-fittings. Therefore the SIF for a Y-fitting must be gotten from: A. hand calculations, B. Y-fitting manufacture, or C. another software program. However the Y-fitting SIF value is calculated, insert this SIF value into the model by making the Tee node point (ex. A03) the active node point. Insert a user SIF using : insert> Xtra Data> Joint Type and User SIF> from the "Joint End Type" drop down listing select "Other". Enter the user defined SIF values and enable the "Override all In-plane and Out-plane SIF's at this point" check-box. 

But wait,

A Tee element has 2 sides: 1. the header side, and 2. the branch side. 

Check the Model listing report or Code Compliance sub-report to be sure that the SIF has been applied to both sides. As seen below the SIF was correctly applied to the Header side but not the Branch side.

Select the other side of the node point and insert another user SIF as shown above. 

6. Again confirm the by reviewing the reports, (ex. Model Listing, Joint type and User SIF data listing):

7. Done!

See Also

Tee, Cross, or Branch Piping Components - Modeling Approaches

Bentley AutoPIPE