Smart Operation Mode Editor

Operation Mode Editor allow you to analyze several operation modes of piping in one project file. Smart Operation Mode Editor is high-level tool. It automatically generates the special template load cases for operation mode and additional force-based loads combination, specified by user. Manual creation of load cases is not needed. User can concentrate on piping design, not on creation of proper load case combinations. Smart operation mode editor will take care on this itself without errors due to human factor and lack of knowledge.

You can add Operation Modes or Force Loads.

Operation Mode - piping operation mode with certain pressure, temperature, fluid weight, support displacements, etc. (1, 2, 3, etc.). Main operation modes is used to model different displacement-based loads on piping. For example main modes could be general operation mode, emergency operation mode, test mode, steaming mode, hog and sag modeling for ship piping etc. Main operation mode has several piping states: hot state, cold state.

Force Loads - additional forces applied to the one of operating modes (4.1, 6.1, etc.). Force loads are used to model additional sustained and occasional forces like safety valve thrust forces, slug flow loads, water hammer loads, blast loads, wind loads, snow loads, ice loads, etc. Concentrated forces are applied in nodes and uniform forces are applied in pipes. The number of force loads is unlimited.

Here are the example of operation modes (below). Piping has five operation modes: Main, steaming, filling, discharging, test. Operation mode 2 has two additional force loads (relief valve 1, relief valve 2).

To see online description of automatically generated load case templates just click help buttons "?":

When all operation modes are added, this window can be closed. You can select the current operation mode on the toolbar. All data will be displayed and entered only for current operation mode. If you open the pipe properties, you will see pressure and temperature only for current operating mode. If you want to see the properties of another operation mode, then you should change the current operation mode and open the pipe properties again.

Properties, that can be changed in different main operating modes:

All other properties can't be changed.

If several operating modes are specified in operation mode editor, then first sustained operating mode is used for La and Lb calculation and these values are used for all operating modes.

If more than one operation mode is specified, then "L" buttons appear near the fields that can be changed in different operation modes. If you click this button you will see all property values in different operation modes.

Default Operating Modes

In new project should be added at least one operating mode. If test mode analysis is checked in project settings, then test mode should be added too. Below you can see the example of minimum set of operating modes for new project. If test mode is not required then first row can be deleted

 

Property

Description

*

Enable/disable operation mode. Just uncheck to disable current operation mode during analysis. You can always check it to enable operation mode again

#

Number of operation mode. Main modes have numbers like "1", "2", etc. The additional force-based loadings have numbers like "2.1", "2.2", "4.3", etc. where first number is main mode number and second number if force loading number

Name

Operation mode name. You can enter any text here

Hanger Sizing

Hangers selection can be done only in one main operation mode. For all other operating modes START-PROF will use already selected springs. You can't check this option for more than one modes. If no options checked then hanger selection will not be performed

High temperature

If at least one pipe element classified as high temperature according to GOST 32388-2013 then this option must be checked, creep diminish and creep self-springing factors must be entered to high temperature pipe elements

Cold state

If this option is checked, then program will calculate additional special mode that called "Cold State". Analysis is done for negative temperature that equal to temperature difference between installation and operation temperature. The initial state for friction forces analysis is Hot state (Operating Mode). For example, if Ambient temperature is -20 and design temperature is +50, then piping will heat up from -20 to +50 and come into main operation mode and after that it will cool down from +50 to -20 and come to cold state. The friction forces change their direction during cooling down. Cold state loads and stresses will be not the same as installation state loads and stresses.

It is recommended to specify only one cold state for one project, because calculation of more than one cold states doesn't have sense

Seismic

If this option is checked, then program will calculate additional load cases with seismic inertial forces at different directions for corresponding operation mode. This option can be checked for several operation modes. For example, if we have two operation modes with temperature 50 and 200 degrees, then seismic loads cases can be checked for each of these modes. You will see what will happen if seismic activity will happen during 50 degree operation mode and 200 degree operation mode

Wind

If this option is checked, then program will calculate additional load cases with wind loads at different directions for corresponding operation mode. This option can be checked for several operation modes. The idea is the same as for seismic loading

Snow

If this option is checked, then program will calculate additional load cases with snow and ice loads for corresponding operation mode. This option can be checked for several operation modes. The idea is the same as for seismic loading

Mode Type

There are several types of mode:

  • SUS - weight and other sustained loads (W+P), Expansion load cases (W+P+T - W+P), Operation loads (W+P+T). Allowable stresses used for sustained loads. Load cases and allowable stresses are generated automatically depending on the selected pipe stress code
  • OCC - weight and occasional loads (W+P+OCC), Expansion load cases (W+P+T+OCC - W+P+OCC), Operation loads including occasional loads (W+P+T+OCC). Allowable stresses used for occasional loads. Load cases and allowable stresses are generated automatically depending on the selected pipe stress code. OCC - occasional load, it can be wind, water hammer, slug flow etc. What is "OCC(k)", "OCC Std", "OCC Alt" please see below
  • TEST - test weight + test pressure (Wt+Pt), operation stress test weight + test pressure + est temperature (Wt+Pt+Tt). Load cases and allowable stresses are generated automatically depending on the selected pipe stress code
  • ASCE 2001 (ALA) - Operation loads including occasional soil displacements, support movements (W+P+T+OCC). Used for support settlement, landslide, mine subsidence analysis. Allowable strain calculated according to ASCE 2001 (ALA) code

  • GB 50470 - Operation loads including occasional soil displacements, support movements (W+P+T+OCC). Used for support settlement, landslide, mine subsidence analysis. Allowable strain calculated according to GB 50470 code

OCC(k)

OCC Std

OCC Alt

k-factor for allowable stress calculation from the occasional loads according to the selected code.

ASME B31.1, ASME B31.9:

ASME B31.3:

  • OCC Std: k=1.33 for low pressure piping. For high-pressure piping (Chapter IX):

  • OCC Alt: Occasional allowable calculation for elevated temperature fluid service 302.3.6 (2) and appendix V. For high-pressure piping (Chapter IX) the same as OCC Std

ASME B31.5: k=1.33

EN 13480:

DL/T 5366-2014:

GB/T 20801-2006: k=1.33

GB 50316-2008:

Time Duration, h

Time duration of current operating mode. Used for ASME B31.3 appendix V calculations of alternative occasional stress and creep-rupture usage factor, u

Stress range between

You can check here between which modes the expansion stress range should be calculated. Stress range can be calculated between main operation modes only

Use Load Factors

Allows to disable overload factors, required by codes EN 13941, GOST 32388, SP 36.13330 and others. Needed for more accurate spring selection. But please note, that after analysis using full overload factors, loads on springs may exceed allowable

Friction Multiplier

Coefficient for friction factors (0...1.0). If you need to perform piping stress analysis without friction - just specify 0. If you will specify 0.5 - analysis will be done with half of friction factors. If you will specify 1.0 - analysis will be done with full friction factors specified in the model.

Friction multiplier of 0 or 0.5 may be used for wind, seismic, water hammer, slug flow, relief valve thrust, and other occasional loads

Spec. Analyze

If this option is checked, then the special analysis like single use compensator cold spring or pre-heating will be performed for current operating mode. The type of analysis is chosen in Project Settings

Weight Multiplier

Zero weight multiplier is used during reducing nozzle loads and adding flexibility to piping. If weight is zero we can be sure, that nozzle loads caused by thermal expansions only. Weight multiplier greater than 1 may be used during transportation stage analysis of piping block or falling to sea bed

Real Load Cases

Real loads cases are generated based on the information specified in operation mode editor. After you run analysis, START-PROF automatically generate template load cases according to operation modes.

A differential friction model is used for START-PROF piping analysis. Sequential transition from one state to another is considered as a chain:"installation mode" - "operating mode" - "cold mode". At each state, an analysis of the deformed state is done. For example, when analyzing in cold mode, the piping in the current stressed-deformed state corresponding to the operating mode is considered and weight plus negative temperature difference (cooling) is added. Friction force is each support is first change direction, while leaving the support in its place, then start to move to their position in installation mode. But supports do not return to their initial (installation) position.

Theoretically, several cycles of "operation state" - "cold mode" occurring during piping use can be considered. But experiments show that the first heating-cooling cycle gives the greatest stress amplitude, so the first cycle is sufficient for determining fatigue failure margins.

Elastic deformation transitions into plastic (residual) deformation in high-pressure pipelines with creep. This leads to gradual decrease of stress in operating mode and negative stress in cold mode. RD 10-249-98 section 5.2 and GOST 32388-2013 use averaging factor χ and relaxation factor δ in safety analysis for pipelines with creep, which decrease the real temperature difference in operating mode and increase it in cold mode. This allows an approximate safety analysis with a margin, but does not give an accurate value of  node displacement, which determines the piping deformed shape, and visible displacement and support loads. Separate analyses are done in START-PROF to overcome this shortcoming:

Table Legend

L - load case

T - design temperature

Tambient - Ambient temperature, input in Project Settings

Tt - test temperature, input in Project Settings

P - design pressure

Pt - test pressure

Sh - allowable stress at hot temperature

Sc - allowable stress at cold temperature

Sy - yield stress at test temperature

St - allowable stress at test temperature

fat - fatigue curve

SUS - sustained

OPE - operational

OCC - occasional

HGR - hanger selection

CLD - cold

EXP - expansion

F - additional non-weight loads. Considered in all operating modes. Not used for seismic load value calculation

Fw - additional weight loads. Considered in all operating modes. Used for seismic load value calculation (Fw+W)

H - variable or constant hanger force

CS - cold spring

W - pipe weight*1.1+Insulation weight*1.2+fluid weight*1.0 or pipe weight+Insulation weight+fluid weight depending on code requirement. Also insulation weight can be zero in installation state

Ww - pipe weight+Insulation weight+(water or zero weight at test state)

D - support displacement at operation state

Dt - support displacement at test state

Dd - Support settlement

E, alfa - elastic modulus and thermal expansion factor

χ - creep stress averaging factor

δ - creep stress relaxation factor

Load Cases for low-temperature piping (RD 10-249-98, GOST R 55596-2013, GOST 32388-2013, CJJ/T 81-2013)

For piping without creep, template loads cases are shown in table below

#

Name

Load case

Allowable stress

One way link

Frict. factor

Spring

E, alfa

Bend k-factor

Output

L1

Hanger selection

W1

-

Calc

0

One-way rigid

T1 or Tambient

P1

spring hanger selection

L2

T1+D1+Dd

-

Calc

0

Stiffness iteration

T1 or Tambient

P1

spring hanger selection

L3

Main Operation Mode 1 (SUS)

W1+P1*+F+Fw+H

1.1Sh1

L4

1

Designed

T1

P1

stress

L4

W1+P1+T1+D1+F+Fw+S+Dd+H

-

Calc

1

Designed

T1

P1

displacements, loads, exp joint

L5

W1+P1*+T1+D1+F+Fw+S+Dd+H

1.5Sh1 pipes

Calc

1

Designed

T1

P1

stress

L4*

W1+T1+D1+F+Fw+S+Dd+H

-

L4

1

Designed

T1

P1

exp joint

L6

Cold mode 1

L4-P1-T1-D1

-

Calc

1

Designed

Tambient

0

displacements, loads

L7

L5-P1*-T1-D1

1.5Sc pipes

Calc

1

Designed

Tambient

0

stress

L8

L5-P1*-T1-D1

-

Calc

0.5

Designed

Tambient

0

-

L9

Expansion

L5-L8

min(1.5(Sh1 + Sc), fat)

-

-

-

-

-

stress

L10

Test Mode

Ww+Pt*+F+Fw+Tt+Dt+Dd+S+H

1.5St

Calc

1

One-way rigid / Designed

Tambient

Pt

stress, displacements, loads

L11

Main Operation Mode 2 (OCC)

W2+P2+F+Fw+H

1.5Sh2

L12

1

Designed

T2

P2

stress

L12

W2+P2+T2+D2+F+Fw+S+Dd+H

1.9Sh2 pipes

1.5(Sh2 + Sc) fittings

Calc

1

Designed

T2

P2

stress, displacements, loads, exp joint

L12*

W2+T2+D2+F+Fw+S+Dd+H

-

Calc

1

One-way rigid / Designed

Tambient

Pt

exp joint

L13

Additional Occasional Loading 1.1

W1+P1+T1+D1+F+Fw+S+Dd+H+F1.1

-

Calc

1

Designed

T1

P1

displacements, loads, exp joint

L14

L13-L5

-

-

-

-

-

-

-

L15

L3+L14

1.5St

-

-

-

-

-

stress

Note * - pressure is assumed to be 0 in RD 10-249-98.

Load Cases for high-temperature piping (RD 10-249-98, GOST 32388-2013)

Load cases for high-temperature piping the same as for low-temperature piping, but have two differences:

 

#

Name

Load case

Allow. stress

one way link

Fric. fact.

Spring

E, alfa

Bend k-factor

Output

L3

Main Operational Mode 1

W1+P1*+F+Fw+H

1.1Sh1

L4

1

Designed

T1

P1

stress

L4

W1+P1+T1+D1+F+Fw+Dd+H

-

Calc

1

Designed

T1

P1

displacements, loads, exp joint

L5

W1+P1*+χ*T1+χ*D1+F+Fw+Dd+H

1.5Sh1

Calc

1

Designed

T1

P1

stress

L4*

W1+T1+D1+F+Fw+Dd+H

-

L4

1

Designed

T1

P1

exp joint

L6

Cold Mode 1

L4-P1-T1-D1

-

Calc

1

Designed

Tambient

0

displacements, loads

L7

Cold With Self-Springing

W1+P1-δ*T1- δ*D1+F+Fw+Dd+H

1.5Sc

Calc

1

Designed

Tambient

0

loads, stress

Note * - pressure is assumed to be 0 in RD 10-249-98.

Load Cases for SNIP 2.05.06-85 and SP 36.13330.2012

Load cases:

 

#

Name

Load case

Allowable stress

one way link

Frict. factor

Spring

E, alfa

Bend k-factor

Output

L1

Hanger selection

W1

-

Calc

0

One-way rigid

T1

P1

spring selection

L2

T1+D1+Dd

-

L1

0

Stiffness iteration

T1

P1

spring selection

L3

Operation Mode 1

W1+P1+T1+D1+F+Fw+S+Dd+H

by code

Calc

1

Designed

T1

P1

stress, displ, loads, exp joint

L3*

W1+P1+T1+D1+F+Fw+S+Dd+H

by code

Calc

1

Designed

T1

P1

stress*

L3**

W1+T1+D1+F1+Fw1+S+Dd+H

-

L3

1

Designed

T1

P1

exp joint

L4

Test Mode

Ww+Pt+Tt+Dt+Dd+S+H

by code

Calc

1

One-way rigid / Designed

Tt

Pt

stress, displ, loads, exp joint

L5

Cold Mode 1

L3-P1-T1-D1

-

Calc

1

Designed

Tambient

0

spring selection

L6

Additional Force loading 1.1

W1+P1+T1+D1+F+Fw+S+Dd+H+F1.1

by code

Calc

1

Designed

T1

P1

stress, displ, loads, exp joint

Note * - analysis uses standard load values without considered load safety factors

Load Cases for ASME B31, EN, GB and DL/T Codes

Template loads cases are shown in table below:

Option 1. Consider hot modulus for support loads (in Project Settings)

Option 2. Stress range from operation to cold (in Project Settings and Stress Table)

Note: SIF and k-facrtors are calculates using maximum pressure from all load cases except occasional and test, and used for all load cases except occasional.

See also piping operating modes for more information.

#

Name

Load case

Allowable stress

one way link, gap

Friction factor

Spring Stifness

E

Alfa

Bend k-factor

Output

LH1

Hanger selection

W1+F1

-

Calc

0

One-way rigid

Tambient or T1
(option 1)

-

P1

spring selection

LH2

T1+D1

-

Calc

0

Stiffness iteration

Tambient or T1
(option 1)

T1

P1

spring selection

L1

Weight in operation State 1

W1+P1+F+Fw+H

SL<k*W*Sh

L5

1

Designed

Tambient

-

P1

stress

L2

Installation state 1

W1+P1+F+Fw+H+CS+Dd1

-

Calc

1

Designed

Tambient

-

P1

displ, loads, exp joint

L3

Operation without pressure 1

W1+F+Fw+H+T1+CS+D1+Dd1

-

L5

1

Designed

Tambient

T1

P1

exp joint

L4

Operation with creep 1

W1+P1+F+Fw+H+χ·T1+χ·D1+Dd1

SL<1.5*Sh

Calc

1

Designed

Tambient

T1

P1

stress

L5

Operation for loads 1

W1+P1+F+Fw+H+T1+CS+D1+Dd1

-

Calc

1

Designed

Tambient or T1
(option 1)

T1

P1

displ, loads, exp joint

L6

Operation for expansion 1

W1+P1+F+Fw+H+T1+CS+D1+Dd1

-

Calc

1

Designed

Tambient

T1

P1

-

L7

Cold after cooling down 1

L6-T1-D1

-

Calc

1

Designed

Tambient

T1

P1

displ, loads, exp joint

L8

Cold after relaxation (creep) 1

W1+P1+F+Fw+H-δ·T1-δ·D1

SL<1.5*Sc

Calc

1

Designed

Tambient

T1

P1

loads, stress

L9

Expansion

L6-L7 or L6-L2 (option 2)

Se<Sa

-

1

Designed

-

-

P1

stress

L10

Test state*

Ww+Pt+H+F+Fw+Tt+CS+Dt+Dd

SL<0.9*Sy

Calc

1

One-way rigid / Designed

Tambient

Tt

P1

stress, displ, loads, exp joint

L11

Additional Force loading 1.1

W1+P1+F+Fw+H+T1+CS+D1+Dd1+F1.1

-

Calc

1

One-way rigid / Designed

Tambient

T1

P1

displ, loads, exp joint

L12

L11-L5

-

-

-

-

-

-

-

-

L13

L1+12

SL<k*W*Sh

-

-

-

-

-

-

stress

On the screenshots below the explanation where are the each load case is used.

Stresses:

Loads, Displacements

Expansion Joint Deformation

Menu Access

File > Operation Mode Editor