Piperack Guide2(7 May,02)

CONTENTS

1.0 GENERAL

A - TERMINOLOGY

A.1. StructureA.2. Foundations

B – DEFINITION CRITERIA

B.1. Rack WidthB.2. Number of tiers

2.0 MATERIAL SELECTION

A – MATERIAL USED

B – SELECTION CRITERIA

3.0 BASIS OF ANALYSIS

A – PERMANENT LOAD

A.1. Weight Of FrameworkA.2. Fireproofing – Heat InsulationA.3. Weight of Piping

B – LIVE LOAD

B.1. Liquid Load In Pipe <12”B.2. Platform and access load

C – EXAMPLES ON THE DETERMINATION FOR THE DISTRIBUTION OF VERTICAL LOAD ON PIPERACK

C.1. Determination of the Average Of Pipes DiameterC.2. Load Distribution Between Main Cross Beam And Intermediate Cross Beam.

D – CLIMATIC LOAD

D.1. SnowD.2. Wind

E – SEISMIC LOAD

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F – TEMPERATURE LOAD

F.1. Structure Expansion Or ContractionF.2. Anchoring – Friction – Piping Guide

G – OTHER LOADS

H – COMBINATION OF LOADS

H.1. Combination of Various Elementary Cases

I – CONDITION OF DEFLECTION

I.1. Acceptable Vertical DeflectionI.2. Acceptable Horizontal Displacement On The Portal Frame

4.0 STEEL PIPERACK

A – CONSTRUCTION ARRANGEMENT

A.1. Intermediate Cross BeamA.2. Longitudinal BeamA.3. Portal FrameA.4. Post-Foundation ConnectionA.5. Longitudinal StabilityA.6. Particular Case

5.0 CONCRETE PIPERACK

A – VARIOUS FORMS

B – METHODS OF EXECUTION

B.1. Racks Cast In PlaceB.2. Racks Semi-PrefabricatedB.3. Racks Completely PrefabricatedB.4. Choice Of Execution Methods

C – STUDIES AND CALCULATIONS

C.1. StudiesC.2. Calculations

D – CONSTRUCTION ARRANGEMENT

D.1. ReinforcementD.2. Fixation of CoolerD.3. Accessories


1.0 GENERAL

1. INTRODUCTION

This document is a guide on the procedures or working methods in the field of civil.

In case of contradiction of this document with the General Protocols, this document superceded the General Protocols.

2. OBJECTIVE

This document covers the regulation by service 347 and 357 of TECHNIP for the piperacks in the petroleum, petrochemicals and similar industries.

Any deviation from this regulation shall be approved by the Head of Service, however the customer particular rules or requirements have priority over this requirement.

3. REFERENCES

This document shall be used with the following documents :-

- GE 357.10.1. Objectives and use of the guide of studies.

- GE 357.10.2. General Rule applicable to the studies.

- GE .357.14.1. Concrete Foundation And Works – General Information.

- GE 357.15.1 Frame and handling – general Information.

A. TERMINOLOGY

Piperacks is a structure made of steel, concrete or mixed supporting :-

- One or more layers of piping.

- Electrical or instrument cable tray.

- Air cooler in certain case.

Piperack comprises of two parts :-

- Steel or concrete structure.

- Concrete foundation.

A piperack composes of various element with the following terminology :-

A.1. Structure

A.1.1. Main Cross Beam

The main cross beam is a horizontal beam connected to two posts to form the portal frame and to support the pipes.


A.1.2. Portal Frame

The element of piperack forms by two posts and one or more main cross beams.

A.1.3. Longitudinal Beam

The longitudinal beam is a horizontal beam connecting two portal frame in longitudinal direction.

Generally, the members are used to support the lateral forces, intermediate cross beams and post of coolers.

Especially to transmit the horizontal force to the bracing bay.

A.1.4 Width of Piperack

The width of piperack is the distance between the axis of the posts.

A.1.5 Piperack Spacing

Piperack spacing is the distance between the portal frames.

A.1.6 Intermediate cross beam

The intermediate cross beam is a horizontal cross members supported by longitudinal beams. They are used to reduce the deflection of small pipes. Their requirement is decided by piping department.

The intermediate cross beam shall be steel.

A.1.7 Longitudinal stability

Longitudinal stability forms by two consecutive portal frame connected by members which restraint the longitudinal forces.


PIPE-RACKS


INTERMEDIATE CROSS BEAM

LONGITUDINAL BEAM

LONGITUDINAL STABILITY= PORTAL SPACING

I = WIDTH OF PIPERACK

MAIN CROSS BEAM

L

PORTAL FRAME

COLUMN

PIPE LAYER LEVEL

A.2. Foundations

A.2.1. Footing

Footing is a member rest on good ground, in the case of pile this is called pipe cap.

A.2.2. Longitudinal Beam

Longitudinal beam is a beam connecting the two consecutive footing in longitudinal direction.

- Longitudinal beam incorporated with the footing.

- Longitudinal beam rested on the footing.

- Longitudinal beam semi-incorporated with the footing.


50

B. DEFINITION CRITERIA

The piperack is define by two principal criteria, i.e. :-

Width of piperack and numbers of tiers.

B.1. Width Of Piperack (normally it is in multiple of 1.5m)

i.e. : 3 meters ; 4.50 meters ; 6 meters ; 7.50 meters ; 9 meters.

B.2. Number Of Levels

1 level cross beam + 1 longitudinal beam



1 level cross beam + 1 level cooler + 2 longitudinal beam




2.0 MATERIAL SELECTION

A. MATERIAL USED

The material used for the piperack structure are as follows :-

- Metal frame- Concrete- Mixed (metal frame – concrete)

B. SELECTION CRITERIA (If the material is not specified by Client)

The selection criteria are :-

- The cost of finishes work.- The completion date.- Nature of contract

The choice of materials used must be made by specialist engineers after detail economic survey in agreement with the project engineer and various factor especially the contract requirement :

- Fireproofing.- Planning schedule (duration)- Reduce time for studies (in the case of standard contract of fixed price for studies).

For overseas contract :

- Cost of transport (distance)- Possibility of material supply locally.- Potential of local labour.

3.0 BASIS OF ANALYSIS

This chapter will explains the determination methods for loads on piperacks.

The guides are as follows :

A - PERMANENT LOAD

A.1. Weight of framework.A.2. Fireproofing – heat insulation.A.3. Weight of piping.

B - LIVE LOAD

B.1. Liquid load in piping with diameter 12”.B.2. Platforms and access load.


C - EXAMPLES ON THE DETERMINATION FOR THE DISTRIBUTION OF VERTICAL LOAD ON PIPERACK

C.1. Determination of average diameter for the pipes.C.2. Load distribution on main cross beam and intermediate cross beam.

D - CLIMATIC LOAD

D.1. SnowD.2. Wind

E - SEISMIC LOAD

F - THERMAL LOAD

F.1. Structure expansion - contractionF.2. Achoring – friction – guide of piping.

G - OTHER LOADS

H - LOAD COMBINATIONS

H.1. Example of various elementary cases.

I - CONDITIONS OF DEFLECTION

I.1. Acceptable vertical deflection.I.2. Acceptable horizontal displacement on portal frame.

A. PERMANENT LOAD

A.1. Weight of framework

The actual weight of the elements constituting the piperacks shall be used especially for concrete piperacks.

Estimated values total weight of piperack :

(including water and pipe) for average dia. 8”

- Pipe-rack 1 level : 80 kg/m2

- Pipe-rack 2 levels : 120 kg/m2

- Pipe-rack 2 levels + cooler : 180 kg/m2

The weight of platforms and access on the piperack to be included.

A.2. Fireproofing and heating insulation.

A.2.1. Weight of fireproofing coating :

See standard (STE.00.17.40.001)

A.2.2. Weight of heat insulator on the lines.

(provided by service piping)


A.3. Weight of pipe

The weight of pipes size between 2” to 12” shall be taken as uniform load as set out in the following sections.

The empty space between pipes can be used (unless stated otherwise) for pipes with diameter equal to the average pipe size.

A.3.1. Dead weight for pipes 2” to 12”

NOMINAL DIAMETER

EXTERNAL DIAMETER

(mm)

SCHEDULE DISTANCE BETWEEN PIPES 150mm TO 300mm

(WITHOUT INSULATION)

DEAD WEIGHT OF PIPES (kg)

Per m Per m2

2” 60.3 40 140 5.4 403” 88.9 40 175 11.3 704” 114.3 40 210 16.2 806” 168.3 40 270 28.6 1108” 219.1 30 325 37.2 12010” 273.1 30 385 52.1 14012” 323.9 30 450 67 150

1) The loads for pipes of > 12” shall be calculated separately.

2) Normally the uniform load per m2 for insulated pipes is smaller than the uninsulated pipes due to the space provided between pipes for the insulated pipes.

A.3.2 Reference Diameter of Piping

The calculation can be simplified by taking the average diameter of pipes for load calculation.

Pipes with diameter more than twice the average diameter of pipes layer shall be considered as follows:-

- Uniform load shall be recalculate without these pipes.

- These pipes shall be consider as point load


A.3.3 Piping Load Distribution Coefficient Between Main Cross Beam (M) And Intermediate Cross Beam (I)

REFERENCEPIPE DIAMETER

SMALLER PIPEDIAMETER

DISTANCE BETWEEN MAIN CROSS BEAM

4.5m 6m 7.5m 9m 12mM I M I M I M I M I

3” - 4” Ø < 2” 0.9 0.1 0.8 0.2 0.7 0.3 0.6 0.4 0.4 0.6Ø 2” 0.9 0.1 0.8 0.2 0.6 0.4 0.4 0.6

6” Ø <3” 0.9 0.1 0.8 0.2 0.7 0.3 0.5 0.5

Ø 3” 0.9 0.1 0.8 0.2 0.5 0.5

8”Ø < 4” 0.9 0.1 0.8 0.2 0.7 0.3 0.5 0.5Ø 4” 0.9 0.1 0.7 0.3 0.6 0.4

10” - 12”Ø < 6” 0.9 0.1 0.8 0.2 0.7 0.3Ø > 6” 0.7 0.3

ZONE A : No intermediate cross beam requires ZONE B : Require more than one intermediate cross beam

Note : When the large pipes can support the smaller pipes, the intermediate cross beam is not necessary.

B. OPERATING LOAD

B.1 Liquid Load For Pipes Ø < 12”

The calculation of the liquid loads in the piping be determined from simplified assumptions as follows :-

- Pipes with 0.5 full of water- Pipes with 0.75 full of water- Pipes with full of water

The choice between the three assumptions will be mentioned on particular rule of the contract :-

- Type of unit (product to be transport) (see service requirement)- Customer preference

B.1.1 Case for Pipes Transporting Gas

In the traditional case, these lines shall be considered as transporting the liquids.

- Particular cases :

Lines for liquid or vapour All the pipes are for gas transportation


ZONE A

ZONE B

To be confirmed by piping discipline

In these particular case, the operating load will be the load provided by the service piping, however the other possible loads due to operation shall be considered.

Liquid phase of the material Present of ice on cold line, etc.

B.1.2 Case for Pipes Ø > 12”

The value of the operation load will be the actual values provided by the service piping.

B.1.3 Operating Load of Piping 12”

NOMINAL DIAMETER

EXTERNAL DIAMETER

(mm)SCHEDULE

DISTANCE BETWEEN

CENTRE OF PIPES

LOAD IN KG½ Full ¾ Full Full

Kg/m Kg/m2 Kg/m Kg/m2 Kg/m Kg/m2

2” 60.3 40 140 1.1 10 1.7 15 2.2 203” 88.9 40 175 2.4 15 3.6 25 4.8 304” 114.3 40 210 4.1 20 6.2 30 8.2 406” 168.3 40 270 9.3 35 14 55 18.6 708” 219.1 30 325 16.5 50 24.8 75 33 10010” 273.1 30 385 26 70 39.1 105 52.1 14012” 323.9 30 450 37 85 55.5 130 74 170

B.2 Platform And Access Load

Load on platform and access shall be considered (value provided on particular rule)

C. EXAMPLES OF CALCULATION FOR DETERMINATION AND DISTRIBUTION OF VERTICAL LOAD ON PIPERACK

C.1 Determination Of Reference Ø OF Pipes

C.1.1 Maximum Pipes Diameter < 12”

- Ø of pipes on the support:- 7Ø2”, 6Ø3”, 8Ø4”, 2Ø6”, 1Ø8”- Pipes are considered full of water

Weight of pipes per m length

- 7 x (5.4 + 2.2) = 53.2- 6 x (11.3 + 4.8) = 96.6- 8 x (16.2 + 8.2) = 195.2- 2 x (28.6 + 18.6) = 94.4- 1 x (37.2 + 33) = 70.2

509.6 kg


24

Dead Load Operating Load

- Average pipe load (Dead Load + Operating Load)

Reference average pipe diameter is 4”

Because 16.2 + 8.2 = 24.4 kg/m > 21.3 kg/m

IMPORTANT NOTE :

Since the largest pipe size is not more than 2 times the average diameter, the option of average pipe is conservative.

When one or more of the pipes obviously deviate from the average diameter, it is better to calculate them separately.

C.1.2 For Pipes with Diameter > 12”

Point loads shall be considered separately for lines with dia > 12”

C.1.3 Particular Case

If it is obvious that the average pipes size in some part is different from the other part, the average pipe for each part shall be used.

C.2 Load Distribution Between Main Cross Beam And Intermediate Cross Beam (Generated By The Pipes)

C.2.1 Pipes Layer with Minimum Ø > 12”

Normally pipes with Ø > 12” do not require intermediate supports.

Load on main cross beam

V = P xL P : Pipe weight per meter lengthL : Distance between main cross beam


C.2.2 Pipes Layer with Maximum Ø < 12”

a) Reference Ø represent the whole pipes on the rack

Example : reference pipe Ø 6”

Vertical load on support is proportional to the width of concerned area.

= L1 x 0.1 = 7.5 x 0.1 = 0.75 m= L2 x 0.2 = 9 x 0.2 = 1.8 m

=

=

For dead load case distribution, load on cross beam will be as follow:

Main cross beam = 110 x 6.97 = 797 kg/mIntermediate cross beam = 110 x 0.75 = 82.5 kg/mIntermediate cross beam = 110 x 1.8 = 198 kg/m

Similar calculation shall be done for operating weight.

b) Average pipes diameter is not including the whole pipes

average Ø 3” +1 line Ø 12”

L = L = 7.5 m (minimum Ø 1”)

Pipes dead weight


1 20

LOAD DISTRIBUTION BETWEEN (IB) AND (MB) AS PER TABLE A.3.3 (PAGE 11)

L1 = 7.5m L2 = 9m

MB

MB

MB

IB IB

For load distribution coefficient refer to § A.3.3

1

2

0

See Table § A.3.1 (Page 10)

Data

Load distribution on the cross beam.

70 x 7.5 x 0.3 = 157 kg/m intermediate cross beam70 x 7.5 x 0.7 = 367 kg/m main cross beam

Point load on the cross beam due to pipe Ø > 12”

Not supported on intermediate beam Load supported by main cross beam

67 x 7.5 = 502.5 kg

Weight of pipe Ø 12” per m length.

Space taken by line 12” Ø = 0.33 m (external diameter)

Point load from pipe Ø 12” shall be reduce by the value equivalent to the 3” ref pipe.

502.5 – (367 x 0.33) = 381 kg

Similar method of calculation shall be performed for operating load.

367 kg/m

C.2.3 Other cases

Similar calculation as above.

C.2.4 Summary

Minimum Ø > 12” Point load to be considered for calculation

Homogenous pipes uniform distributed load

Maximum Ø < 12”

Nonhomogenous pipes(max Ø > 2 x average Ø)

Other cases Uniform distributed load + Point load


P = 381 kg

uniform distributed load+

point load

D. CLIMATIC LOAD

D.1 Snow

The effect of snow on the piperacks support and pipes are not considered (unless otherwise stated in the particular regulation)

D.2. Wind

D.2.1. Wind effect

General expression form :

H = Qh x Ct x Sp

Where

Qh : wind dynamic pressure at height h.Ct : shape factorSp : surface area facing the wind.

D.2.2. Transversal wind

a) Action on the supports

Ct = 1.3 shape factor for flat surface (concrete or fireproof frame)

Ct = 1.8 shape factor for profile steel frame.

For other case see regulation.

The effect of shielding of another parallel elements are not considered.

b) Wind load on pipe layer

H = Qh (Ø + 0.1 x l) x L apply on each horizontal layer.

Where

Ø = Diameter of the largest pipe with a minimum of 250 mm.l = Width of pipe layer.L = Length of pipe layer.


D.2.3. Example of calculation for transverse wind load.

Note :

To simplify the calculation of wind load, the load will be applied :

- At the piping layer elevation,- At the base of column.

However wind load shall be applied at the right location when justified by beam size/or location, mainly for tie beam.

Wind load at Elev = 5.5 : H1

Column : 100 x 1.8 x 0.24 x 2.75 x 2 = 238Longitudinal Beam : 100 x 1.8 x 0.24 x 7.5 x 2 = 648Intermediate Column : 100 x 1.8 x 0.12 x 1.0 x 2 = 43Piping : 100 x (0.4 + 0.1 x 6) x 7.5 = 750

1 680 kg


EL + 5.5

EL + 4.5

Qh = 100 kg/m²Pipe layerLarger Ø = 400

ColumnsMain cross beam

HEA 240

TIE BEAM = 1PE140INTERMEDIATE SUPPORT/ AND COLUMN = HEA 120

6m

7.5m

Column surface for calculation of H1

H1

H2

Column surface for calculation of H1 and H2.

H32.75

2.75

Wind load at Elev. 0 : H2 – H3

Column : 100 x 1.8 x 0.24 x 2.75 = 119 kg

Remark : Wind load distribution on column for pipe rack with two layer of pipes

D.2.4. Longitudinal wind load

a) Action on the supports

Ct = shape factor

Sp = Surface area exposed to wind effect ie:

- All columns

- All relevant transversal supports of first portal / and last one only.

b) Horizontal wind load to be considered at each piping layer

V = Qh x x 1 x L (applied at each piping layer)

Where

= Width of piping layerL = Length of part considered = Friction drag coefficient depending of piping layer location


for calculation of H1



V3

H1

H2

H3

Top layer

Bottom layer

0.1

0.05

0.05 Values of B

c) Wind load on vertical piping layer

Wind parallel to pipe layer.

H = Qh x Sp

Sp = Exposed surface of pipe layer.

d) Wind effect for tee-off pipe lines

Similar method as transversal wind load.

H = Qh (Ø + 0.1 I) L

For isolated pipe line

H = Qh x 0.6 Ø x I

Ø = diameter of concerned pipe line.I = width of concerned pipe.

e) Longitudinal load distribution (steel pipe rack)

Load to be applied :

1. At the tie beam level2. At the base of column


H

Sp

At the tie beam level

H1 = Load applied at the tie beam level on the first portal.H2 = Load applied at the tie beam level on the last portal.

Wind on transverse support.+Wind on horizontal and vertical surface of pipe layer in zone length L1. +Wind on tee off pipe layer in zone L1. + effect of wind on post and bracings in zone L1 (at concerned height).

Wind on transverse support. +Wind on horizontal and vertical surface of pipes layer in zone L2. +Wind on the tee off pipes layer in zone L2.+ effect of wind on post and bracing in zone L2 (at concerned height).


H1 =

H2 =

AREA FOR H, AREA FOR H2

H2H1

H3

h

H5 H5 H3

A B C D

PIPERACK UNDER

CONSIDERATION

L1 L2

STA

RT

ING

PO

INT

STA

RT

ING

PO

INT

At The Base of Column

H3 : Wind load on column (at concerned height)

H5 : Wind load on restrain column and on bracing

Wind load stability post+ at concerned height

Wind load on bracing

f) Load Distribution on Foundation

- Normal Foundation

Longitudinal shear load = H3

- Foundation of stability bay

Longitudinal shearing load =

Vertical load = ± (H1 + H2) x

E SEISMIC LOAD

Important Note

Seismic load shall not be combined with climatic load.

If the particular rule require to check for seismic, it will be checked for para paraseismic regulation.

F THERMAL LOAD

F.1 STRUCTURE EXPANSION/SHRINKAGE

F.1.1 Entirely Steel

Load developed due to steel expansion shall be taken into consideration when it will give abnormal effect on the frame (expansion coefficient 11 x 10-6 per °C)Metal steel frames expose to air, in France it is acceptable for a variation of temperature ± 27°C which is correspondent to the variation in length of ± 0.3 mm per meter length.

Under this conditions, load due to the expansion of the frame is negligible when the distance between two expansion joints does not exceed 60m.

F.1.2 Entirely Concrete

The concrete pipe rack with tie beam cast in situ to the column, the problem will be severe as the beam cannot expand freely. In this


case the effect of expansion or shrinkage of concrete shall be considered as it will result of several bars of constraint.


In practice the distance between the expansion joint shall not exceed the following value :-

30m for pipe rack cast in place 40m for precast pipe rack

F.1.3 Concrete Portal - With Steel Tie Beams

(Similar method as entirely metal).

F.2 ANCHORING - FRICTION - GUIDE OF PIPES

Expansion of hot line pipings create force on their support :

- Friction : movement of lines on their support.

- Anchorage :

Prevent displacement of lines in two directions (anchoring) Prevent displacement of lines in one direction (guide)

Important note :

The vertical load combination for calculating the thermal forces are :-

- Dead loads : Pipes dead weightPipes insulation weight

+- Operating load : Weight of liquids in pipes

This combination will be considered for operating condition.

F.2.1 Consideration of Thermal Forces

a) For intermediate support.

- Anchoring : Intermediate cross beam will not be anchored, Fa = 0.

- Friction : The horizontal force due to longitudinal movement of the pipes will be considered as follows :-

Ff = 0.1 x p

Ff : Force developed at the intermediate sliding support.

p = Vertical load at the intermediate sliding support (operating condition)


The force Ff shall be applied on the top flange of the intermediate cross beam with the following assumptions :-

- Only the inertia of the top flange will be taken for determination of the horizontal bending stress.

- The bending stress in the vertical plane is negligible because of the lateral support provide by the friction lines.

b) On the main cross beam

- Friction (Ff = friction force)

Horizontal force due to pipe movement on the sliding support shall be determined as follows :

Ff = x p x

Ff = horizontal force acting on main support and which development deflection on the horizontal member.

= coefficient of friction between pipes shoes and cross beam.

= 0.4 (steel on steel)

= 0.05 to 0.1 (for teflon or similar)

= Coefficient depend on the percentage of pipes on the cross beam with temperature more than 150°C.

% 0 to 40 0.4

41 to 60 0.6

61 to 80 0.8

81 to 100 1

p = Vertical load acting on main support (operating condition)

- Anchor (Fa = anchoring force)

- The anchoring forces of pipings on the main cross beam shall be provided by piping discipline.

- In practice, the calculation from piping disciplines is not available during the pipe rack design, therefore the design of pipe rack elements are base on the estimate value.

- When the calculations from piping disciplines is available, a final checks shall be performed especially for cross beam.


- The anchoring force always act on the top flange of the cross beam, the design of main cross beam is identical to the previous intermediate cross beam.

IMPORTANT NOTE

- The forces given by piping disciplines are generally large (temperature used for calculation > operating temperature)

- Therefore, partial safety factor used for load shall be taken as 1.

c) On portal (transversal force)

- Horizontal piping forces shall be applied at the main transversal support levels.

- The following factors shall be applied to determine the transversal forces :

Pipe rack off-site

Ft = 0.1 x p : 1st layerFt = 0.05 x p : 2nd layerFt = 0 : other layers

Ft = Transversal horizontal loadp = Vertical load on the support (operating condition)

Site Pipe rack

Ft = 0.15 x p 1st layer (bottom)Ft = 0.1 x p 2nd layerFt = 0.05 x p 3rd layerFt = 0 others layers

Ø - After reception the actual forces, the previous assumption shall be verified.


Ft

Ft

d) On portal (longitudinal forces)

Horizontal anchorage and friction forces developed on the main cross beam shall be applied horizontally at the junction to the column for designing the column itself

e) On stability bay (longitudinal action)

The longitudinal force on pipe rack restrain is the sum of various horizontal forces acting between two expansion joint of pipe rack.

- Anchor

Anchoring force to be applied on the pipe rack restrain is the sum of various anchoring forces on the main cross beam.

- Friction

The total friction force applied on the pipe rack restrain is the sum of various forces on the main cross beam.

Horizontal force acting on pipe rack restrain depend on :-

- Location of pipe rack restrain.

- Number of anchor point for the length of the pipe rack concerned.

Examples :-

Case 1

Stability bay located at the end of piperack.

FA FF FA

Case 2

Stability bay located at the middle of piperack

FF FF

Case 3


FF RN 0

FF FF

FF = 0

FF 0

FA

As shown in the example, it is difficult to generalise a method to determine the total friction force on the piperack.

The value of the anchoring force will reach it maximum when the displacement due to temperature effect has stopped. This mean the combination force of anchoring and friction is only happen during early stage.

Conclusion :

In the operating condition, the anchoring and friction force will not be added for determination of overall forces on the piperack restrain.

Horizontal force due to friction shall be :

Ff = x p x

where = friction factor (sliding / traverse) (0.05 < < 0.4)

= coefficient depends on number of lines with temperature more than 150°C (refer item F.2.1 (b) ).

p = vertical load acting on the concern member.

f) Summary

- For intermediate cross beam (longitudinal action)

• Anchoring : 0

• Friction : 0.1 x p = Ff

- For main cross beam (longitudinal action)

• Anchoring : Estimate calculation for piping design+Verification

• Friction : p x x Ff

- For portal (transversal action)

• Lateral Anchoring (rack off-site)

= 0.1 x p 1st layer (bottom)Ft = 0.05 x p 2nd layer

= 0 x p other layer

• Lateral Anchoring (Site Rack)

= 0.15 x p 1st layer (bottom)= 0.1 x p 2nd layer

Ft = 0.05 x p 3rd layer= 0 x p other layer


- For stability bay (longitudinal action)

• Anchor : sums of all anchoring forces on main support.

• Friction : Ff = x p x

Never add anchor and friction force.

G OTHER LOADS

This document provides the necessary guide for calculation and design of elements in the piperacks for supporting the pipes.

However, by extension a piperack can support :

- hoisting and handling equipment- cooler- boiler

During the progress of the calculation of piperack, the forces due to this equipment shall be considered in the various load cases :

- Dead loads- Live (operating) loads- Climatic loads

It is should be noted that the possible dynamic loads by these equipments shall never be combined with climatic loads.

H LOAD COMBINATIONS

H.1 THE VARIOUS ELEMENTARY CASES

- Dead loads :

Dead weight for :

• members• walkways• pipes P• insulation• fire proofing (operating load only)• liquid loads G• live (passage) loads

Thermal loads

• structure expansion D• anchorage load A• longitudinal friction loads F

- Service climatic load

• transverse wind load Vt• longitudinal wind load Vl


- Seismic load S

- Ultimate climatic load

• transverse wind load Wt• longitudinal wind load Wl


LOAD COMBINATIONS

CASECOMBINATION FOR LOAD

ON FOUNDATIONLOAD COMBINATIONS FOR STEEL STRUCTURE

LOAD COMBINATION FOR CONCRETE STRUCTURE

COMBINATION NO.

NORMAL CASEP + VtP + Vl

1.33 P + 1.5 Vt1.33 P + 1.5 Vl

P + VtP + Vl

12

EXTREME CASEP + WtP + Wl

P + WtP + Wl

P + WtP + Wl

34

SEISMIC P + S P + S P + S 5

SERVICE NORMAL CASE

P + G + A + VtP + G + A + VlP + G + F

1.33 P + 1.5 G + A + 1.5 Vt1.33 P + 1.5 G + A + 1.5 Vl1.33 P + 1.5 G + 1.5 F

P + G + A + VtP + G + A + VlP + 1.2 G + 1.2 F

678

EXTREME SERVICE CASE

P + G + A + WtP + G + A + Wl

P + G + A + WtP + G + A + Wl

P + 1.5 G + A + 1.5 VtP + G + A + WtP + 1.5 G + A + 1.5 VlP + G + A + Wl

9

10

SEISMIC P + G + A + S P + G + A + S P + G + A + S 11

Note : Loading case (D : Structural expansion), any other possible cases shall be added to the combinations.


J CONDITIONS OF DEFLECTION

J.1 ACCEPTABLES VERTICAL DEFLECTION

J.1.1 Steel Piperack

Main Cross Beam

The deflection of these beams due to total “Service” load shall not exceed 1/400 of the length.

Intermediate Cross Beams + Longitudinal Beams

The total deflection (intermediate cross beam + tie beam) under total loads in the service case shall not exceed 1/200 of the intermediate cross beam.

Note :

The deflection given above shall be reduced (information given by piping discipline) when allowable pipe deflection is lower.

J.1.2 Concrete Piperack (Where The Intermediate Cross Beam Is Steel)

Intermediate Cross Beam

The deflection o these beams due to total “Service” load shall not exceed 1/300 of the length.

Others elements

Checking of deflection for beam with L/H < 15 normally is not necessary.

J.2 ACCEPTABLE HORIZONTAL DISPLACEMENT ON THE PORTAL FRAME

J.2.1 Steel Portal Frame

Horizontal displacement due to “normal service wind load” shall not exceed :-

- 1/150 e height of piperack if it is not supporting equipment.

- 1/200 e height of the piperack if it is supporting equipment (air cooler)

J.2.2 Concrete Portal Frame

Due to rigidity of the concrete, a verification of horizontal displacement in piperack is not necessary.(Normal density at reinforcement 150 kg / m³ of concrete and density of concrete 350 kg / m³)


Note :

It should be noted that the uncertainly of the concrete deformation due to development and formation of cracking only give unprecise value of displacement.

4.0 STEEL PIPERACK

A CONSTRUCTION ARRANGEMENT

A.1 INTERMEDIATE CROSS BEAM

Normally the profile of intermediate cross beam is IPE type.

When the percentage of hot lines is high, it is better to use the profile HEA type which provide better inertia in the horizontal direction (friction).

A.1.1 Arrangement Detail

Connection :

This type of connection shall not transmit shearing force to the base of post which produce torsion to the cross beam.

Connection :

- The connection shall be able to ensure the stability of the post due to friction load on the intermediate cross beam.

- The connection is considered partially restraint the horizontal forces from intermediate cross beam.


1INTERMEDIATE CROSS BEAM

CONNECTION

POST

2CONNECTION

LONGITUDINAL BEAM

1

2

In practice, the connection are shown below :-

Connection

POSSIBLE OVERHANG

Connection


POST

GUSSET IF NECESSARY

POSSIBILITY

1

2

A.1.2 Other Provisions

- Intermediate cross beam and members at the same level

- Intermediate cross beam on longitudinal beams



TIE BEAM

POSSIBLE OVERHANG

TIE BEAM


A.2 LONGITUDINAL BEAM

A.2.1 Member Between Spacing

The tie beam profile type IPE is connected to the column by pin joint connection using double cleat.

A.2.2 Spacing > 9 m

The beams shall be make to form lattice.

Height of the lattice 1/15 < h < 1/10 of the spacing

For lattice members, they shall be checked for horizontal buckling (lateral restrain).

A.2.3 Spacing > 12 m

(For low weight pipe layer). The tie beam can be supported by stay wire and braced horizontally.


Stay Wire

For example :

H

= ~ 15 H

Elevation

A.3 PORTAL FRAME

The column are always profile type H to ensure maximum radius of gyration for good buckling strength.

Transverse members generally not made from profile type H, but made from profile type IPE.

The stability of the tranverse portal frame can be ensured by :-

- Stiffners- bracing members


BRACING

STIFFNER

A.4 POST – FOUNDATION CONNECTION

For a continuous piperack, the connection of column to foundation in longitudinal direction to the piperack will be pin-jointed type.

However the connection of column to foundation in the axis of portal can be pin-jointed or fixed type.

A.4.1 Pin Type. (see STC.00.18.10.009)

Advantage :

- no moment transfer

- small size foundation

- two bolts of average diameter

- thin plate without gusset

- simple connection

Disadvantages

- bigger size of the columns and cross beams compared to fixed type connection.

- significant horizontal displacement

A.4.2 Fixed type (see STC.00.18.10.014)

Advantages :

- smaller dimension of the columns and cross beams compared to pin type connection

- reduce horizontal displacement

Disadvantages :

- large foundation

- lot of bolts

- massive connection

- thick base plate and stiffners

Synthesis

The adopted solution will be selected according to technical data (ground characteristic, etc.) and economic (cost of material, nature of contract) by considering the structure (portal + bolt + foundation).


A.5 STABILITY BAY

A.5.1 Purpose

To ensure longitudinal stability of the piperack members due to various horizontal load.

The sections of piperack are separated by methods (oblong holes, corbels) of preventing transmission of horizontal load from one section to another.

The length of the section is limited to 60m for the French climate for negligible effect of thermal expansion.

A.5.2 Choice of Section

The choice of isolation location shall be done according to certain criteria:-

- change in geometric of the piperack (number of levels or width)

- junction of two perpendicular piperack.

- As for as possible, the isolation should not be located, between the principal anchoring of the pipe layer so that the horizontal force apply to the cross member of stability is small.

- An isolation shall be checked for connection of piperack with structures except in the case where the structure ensure the stability of the unit.


F F

INCORRECT POSITION OF

ISOLATION

CORRECT POSITION OF THE ISOLATION FOR THE SECTION

ANCHORING PRINCIPAL

A.5.3 Position of Bracing

- The distance between two bracing stability does not exceed 60m (for French climate).

- The position in the medium of the section is most usually used.

- For piperack with limited bay, the position of stability bracing shall be located at end bay so that the anchoring load do not have to be transmitted from anchoring point at the end of piperack to the stability bracing by tie beam.

- The choice of the position can also depend on obstruction on the ground (road passage, pumps etc.)

A.5.4 Principle

Two general principal are :-

a) Bracing stability bay

Advantages :

Less weight of the structure

Negligible displacement at top which is in agreement with the theory for piping calculation (zero displacement)

Disadvantages

Obstruction on the ground


MAIN BRACING

PRINCIPLE

b) Portal Stability Bay

Advantages :

No obstruction

Disadvantages :

Bigger weight of structure

Top portion displacement is significant

Important Note :

- Attention with uplift for the calculation of the anchor bolt for the stability bay.

- In the calculation for this type of stability bay add a horizontal load at the level of cross beam equal to 1/100 of the sum of vertical load acting on this part.


STIFFNER

PROFILE COMBINATION

A.6 PARTICULAR CASE

Strengthening the main cross beam at the anchoring point.

Principal

Increase the Iy inertial of the main cross beam or provide additional support.


INCREASE Iy ADDITIONAL SUPPORT

ANCHOR

WELDED

MAIN CROSS BEAM

ANCHOR LINE

MINI

IPE BONDS TO CROSS BEAM

PRINCIPLE BY REINFORCEMENT(PROVIDE DRAINAGE)

TO BE PROSCRIBE FOR FIREPROOF CROSS BEAM

HORIZONTAL BRACING

5.0 CONCRETE PIPERACK

A. VARIOUS SHAPES (See Sketch Page 49 to 51)

The concrete piperacks are generally comprises of concrete main frame. The frame is connected by concrete or steel tie beams.

Their standard width are 3m ; 4.5m ; 6m ; 7.5m ; 9m.

They comprise of 1, 2 or 3 stages according to the number of pipe layers to be supported. The cooler also can be supported with or without platform.

When the width of the piperack is less than 3m, normally only one column is required at the centre.



RACK WIDTHL

DISTANCE BETWEEN PORTAL

COLUMN CROSS BEAM TIE BEAM

4500 6000 400 x 400 400 x 300 400 x 300

6000 6000 400 x 400 400 x 300 400 x 300

7500 6000 400 x 400 500 x 300 400 x 300

7500 7500 400 x 400 500 x 300 500 x 300

7500 9000 500 x 400 500 x 300 600 x 300

9000 7500 500 x 400 600 x 300 500 x 300

9000 9000 500 x 400 600 x 300 600 x 300

PREDIMENSIONPIPE RACK 1 LEVELVALID FOR PIPES AVERAGE Ø 12"


VARIOUS METHODS OF EXECUTION

B.1 CAST IN-SITU RACK

All the piperack members are casted at place. No prefabricated member is used.

B.2 SEMI PREFABRICATION RACK

The footings and posts are cast in placed.

The horizontal beams (longitudinal beams, cross beams, tie beams) are prefabricated.

B.3 PREFABRICATED RACK

The footing is cast in place or prefabricated.

The columns and beam (longitudinal beam, cross beam, tie beams) are prefabricated.

Otherwise, all the members of main frame is prefabricated.

B.4 CHOICE OF METHOD OF EXECUTION

The choice depend on 3 criteria :

- size of piperack

- the size of the work which is the most important consideration

- site and weather condition for economic

In fact, it is impossible to impose a priority to the Subcontractor due to following reasons :

Perhaps the selected Subcontractor does not have necessary material for prefabrication.

The local agent of the subcontractor does not want to construct the rack as method prerecognise by TECHNIP. If the subcontractor is requested to follow the TECHNIP prerecognise method, the subcontractor will always try to find ways for change order.

Generally, the subcontractor under estimate the priority of the execution of concrete racks, they will wait at the last minute to look at the drawings.

However, TECHNIP shall advice the subcontractor during invitation to tender.

It should not be believed that prefabrication reduce the cost of the rack appreciably but it can save a lot of time.

In the actual construction, the prefabrication is very employee because same section always kept, so TECHNIP shall make the prefabricated element similar option through out the piperack.


C. ANALYSIS AND DESIGN

C.1 ANALYSIS

C.1.1 Purpose

The preliminary study of concrete piperack is to pre dimension the size of the beams and columns for piping section to detail their drawings.

This predimension shall be made so as to reduce the maximum the divensite squarrings to facilitate the prefabrication.

C.1.2 Method

- With referring to the general arrangement drawings, list out the data (average Ø of pipes, elevation of cross beam, longitudinal beam etc.

- Using the tables of predimension below, determine the various sections.

- With all these data, establish the preliminary piperack drawing.

- Determination of position of anchoring bay with the position of longitudinal beam.

Note :

If possible, the dimension of the footing is carried out during the calculation for reinforcement. It is necessary to indicate the bottom level of foundation and dimension, for presence of other foundation, pipe & etc.

The table of predimensions are valid for normal case, however the designer need to check it.


RACK WIDTHL



4500 6000 400 x 400 400 x 300 400 x 300

6000 6000 400 x 400 400 x 300 400 x 300

7500 6000 400 x 400 500 x 300 400 x 300

7500 7500 400 x 400 500 x 300 500 x 300

7500 9000 500 x 400 500 x 300 600 x 300

9000 7500 500 x 400 600 x 300 500 x 300

9000 9000 500 x 400 600 x 300 600 x 300

PREDIMENSIONPIPE RACK 1 LEVELVALID FOR PIPES AVERAGE Ø 12"


RACK WIDTHL



4500 6000 400 x 400 400 x 300 400 x 300

6000 6000 400 x 400 400 x 300 400 x 300

7500 6000 500 x 400 500 x 300 400 x 300

7500 7500 500 x 400 500 x 300 500 x 300

7500 9000 600 x 400 600 x 300 600 x 300

9000 7500 600 x 400 600 x 300 500 x 300

9000 9000 600 x 400 600 x 300 600 x 300

PREDIMENSIONPIPE RACK 2 LAYERSVALID FOR PIPES AVERAGE Ø 12"


RACK WIDTHL


COLUMN CROSS BEAMTIE BEAM

UPPER LOWER

7500 6000 700 x 500 700 x 400 700 x 400 400 x 300

7500 7500 700 x 500 700 x 400 700 x 400 500 x 300

7500 9000 800 x 500 800 x 400 800 x 400 600 x 300

9000 7500 800 x 500 800 x 400 800 x 400 500 x 300

9000 9000 800 x 500 800 x 400 800 x 400 600 x 300

PREDIMENSIONPIPE RACK 1 LEVEL + AEROSVALID FOR PIPES AVERAGE Ø 12"


RACK WIDTHL



UPPER LOWER

7500 6000 700 x 500 600 x 300 700 x 400 400 x 300

7500 7500 700 x 500 600 x 300 700 x 400 500 x 300

7500 9000 800 x 500 700 x 400 800 x 400 600 x 300

9000 7500 800 x 500 700 x 400 800 x 400 500 x 300

9000 9000 800 x 500 700 x 400 800 x 400 600 x 300



RACK WIDTHL



UPPER LOWER

7500 6000 700 x 500 600 x 300 700 x 400 400 x 300

7500 7500 700 x 500 600 x 300 700 x 400 500 x 300

7500 9000 800 x 500 700 x 400 800 x 400 600 x 300

9000 7500 800 x 500 700 x 400 800 x 400 500 x 300

9000 9000 800 x 500 700 x 400 800 x 400 800 x 300



C.2. DESIGN

C.2.1 Purpose

The calculation of concrete piperacks is to establish the data of loads acting on the piperack in order for the calculation of reinforcement in order to obtain the quantity of concrete, reinforcement and formwork for costing.

C.2.2 Checking The Reinforcement

The amount of reinforcement in the member shall not exceed 150 kg/m³ of the concrete. The size of the section shall be increase if the amount of reinforcement is high.

D. CONSTRUCTION DETAILING

D.1 REINFORCEMENT

In order to facilitate the execution of piperack at site, the reinforcement of all the elements shall be detail as follows :

D.1.1 Column

See sketch below.

Steel for the columns are similar except for the diameter (range between Ø12 and 25).

COLUMN 400 x 400REINFORCEMENT DETAIL


12 to 25

400

4590

9045

130

COLUMN 400 X 600REINFORCEMENT DETAIL






D.1.2 Beam (Main Cross Beam or Tie Beam)

The position of reinforcement at the support of the tie beam can be moved to allow for insert plate.

It is necessary to inform the subcontractor that the prefabricated member shall be marked accordingly as per plan of assembly in order to prevent discrepancies during installation.


D.2. FIXATION OF AIR COOLER

The air coolers are installed on piperack in four different ways, i.e.:

D.2.1 Cooler Directly Install on Tie Beams

D.2.2 Post of Cooler Rest on Tie Beams


D.2.3 The Feet of Cooler on Overhang Beam Supported on Tie-Beam

D.2.4 Feet of Cooler on Slab Supported by Tie-Beam


D.3 ACCESSORIES

Accessories are required for fixing of small frames, piping slide, installation of electric elements.

The accessories are base plate, posts, sleeves, rails.

See diagram below :-


D.3.1 Base Plate or Insert Plates

Base plate or insert plates are used for fixing (particularly the post) the secondary steel frames for supporting pipings, walkways etc.

D.3.2 Flat Plate on Cross Beam and Tie-beam

It is needed for allowing slip of pipings and fixing of anchor on the cross beams or tie-beams. The flat plates are generally 150 mm wide x 10 mm thick.

Flat plate must be provided on the cross beams and fix to the concrete by steel Ø 8.

Flat plates only be provided on tie-beam when required or when there is piping.

Dimension could be as shown below :-

Special “steel-concrete” adhesive can be used if the plats have not be installed during casting of concrete.


50 50

4 x 8 per metre

FLAT PLATE 150 x 10

120

10 55

150

50

8 welded

These special adhesives are produce by companies such as :-

- “BOSTIK”

or

- “SIKA”

The products are constantly upgraded or revise, therefore the manufacturer shall be contacted for the latest product suitable for the specific condition.

D.3.3 Sleeves

The sleeves are made of plastic.

As a guide the following are some of the brand :-

- ARMOSIG : Elysee 2 - 78170 LA CELLE SAINT CLOUD B.P. n° 2

- SEPEREF - TMP - Z.I. QUINCIEUX - 69650 SAINT GERMAIN AU MONT D’ OR B.P. n° 1

Generally, the diameter sleeves are 22.6 or 25 mm.

D.3.4 Rails

They are embedded in the concrete during casting.

It exist in various types and dimensions produced by many manufacturers as listed below :-

- Rails “HALFEN” distributed by :

Societe SODIMETAL S.A.Immeuble Evolution18, Rue Goubet75940 PARIS Cedex 19 – Tel. 200.67.01

- Rails “JORDHAL” distributed by :

ACIBATZ.I. 68190 UNGERSHEIM – Tel. (89) 48.13.03

- Rails “TRIMBORN” distributed by :

TECNER25, Rue Trebois92300 LEVALLOIS-PERRET

It comes with various coating such as black, galvanised, paint, polymer, stainless steel.


As an indication, a profile 50/30, the basic load is 4.5 ton/meter length with 4 bolts Ø 20.

D.3.5 Conclusion

The accessories increase the cost of the concrete piperack, therefore it shall be reduced to minimum.

It is obvious that the use of anchoring rail will make it easy to fix apparatus or secondary frame. However as it is very costly, it shall not be their installed especially for ‘turnkey contract”. In the service contract, they only be used when requested by client.

The used of plastic “sleeves” shall be maximise as it is rather cheap.

The used of plats on the cross beam are compulsory.

The plats on tie-beam are optional. The need is decided after studing the general drawings.

The plats are anchor to the concrete, if they are install before casting of concrete or adhesive by special product. The adhesive cannot be used for slide (anchoring of lines).


Documents

Piperack Guide2(7 May,02)