Bab 08 Hanger

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Chapter VIII Hangers

EDC - ITBTraining on Caesar II

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BAB VIII

HANGERS

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8.2 Simple Hanger Design

No additional input

Globally (in hanger

control)locally (on each

hanger auxiliary data

area)

Note that a number of the parameters

from the hanger control sheet also show

up on the individual hanger auxiliary

data fields.

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8.3 Single Can Design

distance betweenthe pipe support and the

concrete foundation, or

baseplate.

Indicate that the pipe is supported from

below by entering a negative number in the

Hanger/Can Available Space field on the

hanger spreadsheet.

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8.4 Constant Effort Support Design

Constant effort support

Very small allowable travel

0.01 in

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8.5 Inputting Constant Effort Supports (No Design)

1. Enter the constant effort

support load (per hanger)

in the Predefined Hanger

Data field.

2. Enter the number of

constant support hangers at

the location.

Step :

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8.6 Entering Existing Springs (No Design)

1. Enter the Spring Rate and

the Theoretical Cold Load

(installation load, on a per

hanger basis) in the

Predefined Hanger Data

fields.

2. Enter the number of

Variable Support Hangersat the location.

Step :

Theoretical Cold Load = Hot Load +

Travel * Spring Rate

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8.7 Multiple Can Design

Positive number

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8.8 Old Spring Redesign

the hanger table

the number of springs

at the location

the old spring rate

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8.9 Pipe and Hanger Supported From Vessel

Connecting nodes

associated with hangers

and cans function just

like connecting nodes

with restraints.

Connecting node

displacements are

incorporated in thehanger design algorithm.

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8.10 Hanger Design with Support Thermal Movement

The hanger at node 9 is

supported from a

structural steel extension

off of a large vertical

vessel. The vessel at thepoint where the hanger is

attached grows thermally

in the plus Y

direction approximately3.5 in.

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8.11 Hanger Between Two Pipes

The directive Connect Geometry through CNodes must be turned off

in the

Configuration Setup to avoid plot and geometry errors.

Node on the pipe

passing overhead

Rigid element

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8.12 Hanger Design with Anchors in the Vicinity

the anchor at 5 is freed in the Y-direction,

the anchor at 105 is freed in all directions.

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8.13 Hanger Design with User-Specified Operating Load

In this configuration, freeing the anchors at 5 and 60 didnt help the thermal case nozzle loads.

It was postulated that, due to the stiffness of the overhead branches, the hanger calculated hot

load was not sufficient. The calculated hot load was 2376 lb. A new hot load of 4500 lb. is tried

here.

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8.14 Spring Can Models with Bottom-Out and Lift-Off

Capability

Grinnell, fig.B268, size 10 :

theoretical cold load: 1023 lb.

spring rate : 260 lb./in.

smallest load : 910 lb.

largest load : 1690 lb.

Bottom out :

in4346.0260

1091023

rateSpring

LoadMin.TableLoadInstalled

Lift-off :

in565.2

260

10231690

rateSpring

LoadInstalledLoadTable.Max

Value for the gaps g1 = 0.4346

g2 = 0.4346 + 9.1E-6

g3 = 2.5650Min. Table Load : 910 = 9.1E-6 in

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Example: Input for Lift-off and Bottom-out Spring Can Model (continued)

The gap field in the restraints auxiliary data area rounds off values to 3 decimal

places for display only. Internally, CAESAR II stores values to 7 digits for

calculations. Therefore the gap corresponding to the -Y restraint in this example

was input as 0.4346 + 9.1e-06 and this value will be retained in memory for

calculations.

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8.15 Spring Hanger Model With Rods, Bottom-

Out, and Lift-Off

Grinnell, fig.B268, size 10 :

theoretical cold load: 101 lb.

spring rate : 200 lb./in.

smallest load : 600 lb.

largest load : 1300 lb.

Bottom out :

in055.2260

0601011

rateSpring

LoadMin.TableLoadInstalled

Lift-off :

in445.1200

10111300

rateSpring

LoadInstalledLoadTable.Max

Value for the gaps

g1 = 0.4346 g2 = 0.4346 + 9.1E-6

g3 = 2.5650Min. Table Load : 600 = 6.0E-6 in

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Dummy rigid modeled between nodes 10 and

15. Pipe connected to the rod through a +Y

restraint.

Example: Bottom-out and Lif t-off Spring

Hanger Model with Rods

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8.16 Simple "Bottomed-Out" Spring

Gap : x (permitted travel)

Mu : F (initial load)

Note that no hanger should be entered at the same

position as a bottomed-out spring.

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8.17 Modeling Spring Cans with Friction

A rigid element from the pipe center to the top of the can. Length

equals pipe radius + insulation thickness + shoe height + any

trunnion height.

A Cnode to connect to the spring. Except for the vertical spring

stiffness, all other DOFs are rigidly connected. A rigid element representing the spring can height.

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EDC ITBTraining on Caesar II

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Bab 08 Hanger

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