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Piperack Guide2 7 May 02

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Text of Piperack Guide2 7 May 02

CONTENTS 1.0 GENERAL A - TERMINOLOGY A.1. A.2. Structure Foundations

B DEFINITION CRITERIA B.1. B.2. 2.0 Rack Width Number of tiers

MATERIAL SELECTION A MATERIAL USED B SELECTION CRITERIA

3.0

BASIS OF ANALYSIS A PERMANENT LOAD A.1. A.2. A.3. Weight Of Framework Fireproofing Heat Insulation Weight of Piping

B LIVE LOAD B.1. B.2. Liquid Load In Pipe 12 shall be calculated separately. 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

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A.3.3

Piping Load Distribution Coefficient Between Main Cross Beam (M) And Intermediate Cross Beam (I) SMALLER PIPE DIAMETER DISTANCE BETWEEN MAIN CROSS BEAM 4.5m M I 0.9 0.1 6m M 0.8 0.9 0.9 0.9 I 0.2 0.1 0.1 0.1 7.5m M I 0.7 0.8 0.8 0.9 0.8 0.9 0.9 0.3 0.2 0.2 0.1 0.2 0.1 0.1 9m M 0.6 0.6 0.7 0.8 0.7 0.7 0.8 I 0.4 0.4 0.3 0.2 0.3 0.3 0.2 M 0.4 0.4 0.5 0.5 0.5 0.6 0.7 0.7 12m I 0.6ZONE B 0.6

REFERENCE PIPE DIAMETER

3 - 4 6 8 10 - 12 ZONE A ZONE B Note B. :

< 2 2 6 : :

ZONE A

0.5 0.5 0.5 0.4 0.3 0.3

No intermediate cross beam requires Require more than one intermediate cross beam

To be confirmed by piping discipline

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

OPERATING LOAD B.1 Liquid Load For Pipes < 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 :B.1.1 Type of unit (product to be transport) (see service requirement) Customer preference

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

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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. B.1.2 Liquid phase of the material Present of ice on cold line, etc.

Case for Pipes > 12 The value of the operation load will be the actual values provided by the service piping.

B.1.3 NOMINAL DIAMETER 2 3 4 6 8 10 12 B.2

Operating Load of Piping 12 DISTANCE BETWEEN CENTRE OF PIPES 140 175 210 270 325 385 450 Full Kg/m 1.1 2.4 4.1 9.3 16.5 26 37 Kg/m 10 15 20 35 50 70 852

EXTERNAL DIAMETER (mm) 60.3 88.9 114.3 168.3 219.1 273.1 323.9

SCHEDULE

LOAD IN KG Full Kg/m 1.7 3.6 6.2 14 24.8 39.1 55.5 Kg/m 15 25 30 55 75 105 1302

Full Kg/m 2.2 4.8 8.2 18.6 33 52.1 74 Kg/m2 20 30 40 70 100 140 170

40 40 40 40 30 30 30

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

C. C.1

EXAMPLES OF CALCULATION FOR DETERMINATION AND DISTRIBUTION OF VERTICAL LOAD ON PIPERACK Determination Of Reference OF Pipes C.1.1 Maximum Pipes Diameter < 12 of pipes on the support: 72, 63, 84, 26, 18 Pipes are considered full of water

Weight of pipes per m length 7 x (5.4 + 2.2) 6 x (11.3 + 4.8) 8 x (16.2 + 8.2) 2 x (28.6 + 18.6) 1 x (37.2 + 33) = = = = = 53.2 96.6 195.2 94.4 70.2 509.6 kg

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Dead Load

Operating Load

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-

Average pipe load (Dead Load + Operating Load)=2 1.3 kg/m len gth

5 10 24

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 > 12 Normally pipes with > 12 do not require intermediate supports. Load on main cross beam V = P xL P : Pipe weight per meter length L : Distance between main cross beam

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C.2.2

Pipes Layer with Maximum < 12 a) Reference represent the whole pipes on the rack Example : reference pipe 6

1

0

2

MB

MB

L1 = 7.5m

L2 = 9m

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

Vertical load on support is proportional to the width of concerned area.1 2

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

0

L1 L 0.9 + 2 0.8 2 27.5 9 0.9 + 0.8 = 8.97 m 2 2

For load distribution coefficient refer to A.3.3

For dead load case distribution, load on cross beam will be as follow: Main cross beam Intermediate cross beam Intermediate cross beam = 110 x 6.97 = 797 kg/m = 110 x 0.75 = 82.5 kg/m = 110 x 1.8 = 198 kg/m See Table A.3.1 (Page 10)

Similar calculation shall be done for operating weight. b) Average pipes diameter is not including the whole pipes average 3 +1 line 12 Data L = L = 7.5 m (minimum 1) Pipes dead weight

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MB

IB

IB

Load distribution on the cross beam. 70 x 7.5 x 0.3 = 157 kg/m intermediate cross beam 70 x 7.5 x 0.7 = 367 kg/m main cross beam Point load on the cross beam due to pipe > 12 Not supported on intermediate beam Load supported by main cross beam

67 x 7.5 = 502.5 kg Weight of pipe 12 per m length. Space taken by line 12 = 0.33 m (external diameter) Point load from pipe 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. P = 381 kg

367 kg/m

C.2.3

Other cases Similar calculation as above.

C.2.4

Summary Minimum > 12 Point load to be considered for calculation Homogenous pipes Maximum < 12 Nonhomogenous pipes (max > 2 x average ) uniform distributed load + point load uniform distributed load

Other cases

Uniform distributed load + Point load

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D. D.1

CLIMATIC LOAD 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 factor Sp : 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 ( + 0.1 x l) x L apply on each horizontal layer. Where = Diameter of the largest pipe with a minimum of 250 mm. l = Width of pipe layer. L = Length of pipe layer.

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D.2.3. Example of calculation for transverse wind load. Qh = 100 kg/m EL + 5.5 EL + 4.5 HEA 240 Columns Main cross beam TIE BEAM = 1PE140 INTERMEDIATE SUPPORT/ AND COLUMN = HEA 120 7.5m Pipe layer Larger = 400

6m

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 Longitudinal Beam Intermediate Column Piping : : : : 100 x 1.8 x 0.24 x 2.75 x 2 100 x 1.8 x 0.24 x 7.5 x 2 100 x 1.8 x 0.12 x 1.0 x 2 100 x (0.4 + 0.1 x 6) x 7.5 = = = = 238 648 43 750 1 680 kg

Column surface for calculation of H1 H1 2.75

2.75

H3

H2

Column surface for calculation of H1 and H2.

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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 H1 for calculation of H1 H2 for calculation of H2

H3

for calculation of H3 V3

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 Top layer = Length of part considered = Friction drag coefficient depending of piping layer location 0.1

0.05 Bottom layer 0.05 Values of B

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