flange modeling approaches

8/11/2019 Flange Modeling Approaches

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1. Modeling Approaches, Tips, Technique for Flanges

Piping Components in AutoPIPE

Attention:Please see the following AutoPIPE help section:

Help > Contents> Contents Tab> Modeling Approaches> Modeling Approaches>

This help has been provided in order to give users ideas for modeling tpical piping

arrangements! The steps shown in each e"ample should not be ta#en as the onl

method available to create models! In addition$ the intent of the e"amples is to present

was to create ade%uate models of speci&c piping components for analtical purposes!

Anchors 'ends

Cuts (le"ible )oints

(rames Hangers

*o++les Pipes

,educers ,otating E%uipment

-upports Tees

.alves .essels

2. Questions, and Answers:3. Item #1. How to model typical fanges in AutoPIP !"i.$ and %ower:

Answer:In AutoPIPE ./i 0!1 and lower$ 2anges are a 3 point element with no

length> The program onl considers the 2ange weight and weld connection for

-I( calculations! Assuming 2ange sti4ness is same as the pipe is technicall

incorrect because a 2ange is more rigid than pipe! However$ it does *5T a4ect

analsis results to an signi&cant e"tent! 6ou can choose to model a 2ange as a

single point or ta#e into consideration the actual 2ange length!

-ee the following procedure to model the actual 2ange length:

A! Assuming a 2anged no++le connection to be anchord to a vessel$ insert

an anchor!

'! Insert a short run of pipe e%ual to the actual 2ange length!

C! Insert another pipe run and to the ne"t node point in the model!

7! Insert a 2ange at *o++le interface$ in this e"ample$ start of the

segment8anchor point! 5n the 2ange dialog$ change )oint End Tpe 9 ;ser


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7e&ned$set )oint -I( 9 3!


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'! Insert a Pipe run half the total length of the Hanger 2ange =e"! '

)oint Tpe user -I(! -elect the correct tpe of end connection or enter a user-I(!

G! Connection to support: choose one of the following$ model connection as

simple supports or model with soil properties

*otes:

i! Model connection as simple support: add additional node points =e"! '


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ii! Model connection with soil properties: add additional node points to

represent pipe entombed in concrete! Insert -oil properties over same node

points added! -elect all the pipe with in the concrete and appl the correct

soil properties to mimic concrete!

. Item #3. *odel a Hanger fanges:

Answer:Hanger 2anges are considered to be bolted to a structure!

Modeling approach:


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A! 5n the segment where the 2ange is to be modeled$ insert a node point

=e"! '

)oint Tpe user -I(! -elect the correct tpe of end connection or enter a user

-I(!

G! Connection to support: choose one of the following$ model connection as

simple supports or model with beam elements

*ote: i! Model connection as simple support: Insert AutoPIPE supports

as need at the 2ange center point =e"! '


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$. Item #), How to model a -tu nd, -wi(el, or*isalignment /lange

Answer: The swivel 2ange is used with medium service pressures at points where the

bolt holes in the mounting 2anges are not precisel aligned! The swivel 2ange simpli&es

&tting between J &"ed points!


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Answer:(or strss analsis purpose$ the program needs to #now the weight and

-I( associated with a 2ange! Most A-ME piping codes do not have

established -I( values for these tpes of 2anges! @hilst A-ME 31! and 31!D

codes are applicable for weld nec# 2anges$ the are not applicable to swivel

ring 2anges beond the bolt pattern and bolt si+es! A-ME o4er alternative rules

that consider swivel ring 2anges as nonstandard$ or loose tpe$ 2anges!

Therefore the modeling appraoch for these tpes of 2anges:

-elect the node point where the 2ange is to be located$ press Insert> (lange>$on the 2ange dialog screen enter:

(lange tpe 9 *-

Pressure ,ating 9 *-

@eight 9 enter weight from vendor literature

)oint End Tpe: ;ser 7e&ned

)oint -I(: contact 2ange manufature for value to be used!

*ote: 5ne could argue to set )oint end tpe 9 Kap oint in order to

automaticall calcuale the -I(! However$ since these tpes of oints are not

covered b the applicable piping code$ ou will need to use engineering

udgement or contact the manfacture! 'entle T-G cannot provide a de&native

value!
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