Define the 6-inch bypass - CAESAR II - Reference Data

CAESAR II Applications Guide

PPMProduct
CAESAR II
PPMCategory_custom
Reference Data
Version_CAESAR
12

You now return to the 6-inch bypass piping around the 8-inch check valve above the pump. The welding tee nodes of 10 and 25 are defined as reducing tees when you model the 6-inch piping elements. Start the bypass from node 10 and create elements with 600-series nodes.

Node 10-605 Pipe Element

The first element of the bypass runs from the reducing tee at node 10 to the intersection of the horizontal pipe centerline and the vertical pipe centerline (node 605). The length of the element is 2 ft.

  1. Click Continue on the Navigation Tools toolbar.

    The To node displays 40 and the From node displays 45. The software assumes that you want to continue modeling from the last-created node.

  2. Type 10 in the From node box and type 605 in the To node box.

  3. In the DX box, type -2-. The software measures the element length from the 8-inch centerline to the centerline of the vertical 6-inch line.

  4. In the Diameter box, type 6 to specify the nominal pipe size of 6 in.

    The software replaces the nominal value with the actual outer diameter (OD) of 6.6250 in.

  5. In the Wt/Sch box, type S to specify standard wall thickness in inches.

    The software replaces S with the actual wall thickness of 0.2800 in.

Node 605 Elbow

Node 605 defines the first 90-degree elbow of the bypass. The software adds nodes at the elbow near point and far point.

  1. Double-click the Bend check box to display the Bends tab on the right.

    The software creates a long radius elbow (1-1/2 times the nominal pipe diameter) for the 6-inch line, node 603 at the elbow near point (Angle 2 of 0.000), and node 604 at the midpoint (Angle 1 of M). Node 605 moves to the elbow far point.

  2. In the Type list, select 1 -Single Flange.

    Similar to the previous elbows, the elbow does not display until you create the next pipe element.

Each elbow on the bypass is flanged on the end closest to the gate valve. The flange acts like a stiffening ring, reducing the bending flexibility of the elbow. This characteristic of flanged elbows is addressed by the piping codes through a modification of the flexibility factor and stress intensification for the elbow.

Node 605-610 Pipe Element

This short element runs from the far point of the elbow (node 605) to the beginning of the bypass gate valve (node 610).

  1. Click Continue on the Navigation Tools toolbar.

    The To node displays 610 and the From node displays 605.

  2. In the DY box, type 9 to specify the element length of 9 in.

    The horizontal elbow and the new horizontal pipe element display.

    The 9-inch length puts node 610 at the far end of the bend. The locations of nodes 605 and 610 are coincident. To prevent a zero-length element, the software attaches an element length of 0.45 in., equal to 1 percent of the bend radius.

You can change the default 1percent attachment length by specifying a new value for Bend Length Attachment Percent in Tools > Configure/Setup .

Node 610-615 Gate Valve

This element is the 6-inch 150-psi class flanged gate valve.

  1. Click Continue on the Navigation Tools toolbar.

    The To node displays 615 and the From node displays 610.

  2. Click Valve/Flange Database on the Input Tools toolbar.

    The Valve and Flange Database dialog box displays.

  3. Select GATE from the Rigid Type list and FLG from the End Type list. Click OK.

    A 150 psi class flanged gate valve displays.

    The software adds valve data to the Classic Piping Input dialog box. The element length DY is 1 ft. 5.750 in., Rigid is selected, and the weight of the valve and flanges of 225.000 displays in the Rigids tab. The software includes these values in the analysis.

Select NOFLG in the End Type list of the Valve and Flange Database dialog box if you do not want to include the deadweight and length of the attached flanges in the analysis.

Node 615-620 Pipe Element and Node 620 Elbow

This element runs from the end of the gate valve (node 615) to the top horizontal pipe centerline and the vertical pipe centerline (node 620).

You need to find the Y distance between nodes 615 and 620, where 620 is at the same height as the top welding tee node 25.

  1. Click Distance on the Input Tools toolbar.

    The Distance dialog box displays.

  2. Select Between Element Nodes and To and From Nodes, type 615 and 25 as the nodes, and then click Calculate.

    1' 3" displays as the needed DY distance.

  3. Click Continue on the Navigation Tools toolbar.

    The To node displays 620 and the From node displays 615.

  4. In the DY box, type 15 to specify the element length of 1 ft. 3 in.

  5. Double-click the Bend check box to display the Bends tab on the right.

    The software creates a long radius elbow (1-1/2 times the nominal pipe diameter) for the 6-inch line, node 618 at the elbow near point (Angle 2 of 0.000), and node 619 at the midpoint (Angle 1 of M). Node 620 moves to the elbow far point.

  6. In the Type list, select 1 -Single Flange.

    Similar to the previous elbows, the elbow does not display until you create the next pipe element.

Node 620-25 Pipe Element Closing the Bypass Loop

This element runs from the far point of the top bypass elbow to the reducing tee at node 25, returning the 6-inch pipe to the 8-inch pipe and closing the bypass loop.

  1. Click Continue on the Navigation Tools toolbar.

    The To node displays 625 and the From node displays 620.

  2. Type 25 in the To node box.

  3. Click Close Loop on the Input Tools toolbar.

    The software creates the element and displays the length of 2 ft. in the DX box.

  4. To save the model click Save or File > Save.

  5. Click Distance . Select Between Element Nodes, type 5 (the first element) and 40 (the last element) in the boxes, and then click Calculate. In Results, the length should be 26' 8 3/8". Write down this value for later comparison in Tutorial B.

Your model is complete!