STATIC EQUIPMENT SECTION

TANK LOADING DATA Basic Concepts

INTER DISCIPLINE TRAINING August 20, 2009

OBJECTIVE

To understand the different factors

affecting tank loading

To learn the basic philosophy in analyzing

the different loadings in the tank

Interface with Civil to Produce Loading

Data

CIVIL STATIC

Mechl D/S & Loading Data

Basic Data

a. Wind Speed

b. Wind Zone

c. Site Class

d. Ss / S1

Typical Tank L/D Output

Empty Weight without Insulation

WE = Empty weight without insulation, (Ton)

Bottom Plate

Shell Plate

Roof Plate

Wind Girder

Appurtenance

= Bottom plate wt. + Shell plate wt. +

Roof plate wt. + Wind girder wt. +

Appurtenance wt.

Total Weight

WT = Total weight, (Ton)

Bottom Plate

Shell Plate

Roof Plate

Wind Girder

Appurtenance HLL

Insulation

= Empty wt. w/o insulation, WE +

Insulation wt. + Liquid operating wt.

Horizontal Force by Wind

FW = Horizontal force due to wind, (Ton)

Note:

a) FWR or FWS is the wind horizontal force

w/c is the wind pressure at a certain height

multiply by the projected area normal to

wind.

b) FW varies depending on the project

(i.e. constant wind pressure or varying wind

pressure)

FWR

FWs

FW = FWR + FWS = qz x G x Cf x Af ---> NSCP 5th ed, 2001

Overturning Moment by Wind

MW = Overturning moment due to wind,

(Ton-m)

FWR

FWs h2

h1 MW

MW = (FWS x h1) + (FWR x h2)

Horizontal Force by Earthquake

FE = Horizontal force due to earthquake,

(Ton)

= Seismic base shear V (API 650, App.E)

API 650, Appendix E Method:

V = sqrt (Vi2 + Vc2)

Where:

Vi = Ai * WT

Vc = Ac * Wc

Ai = impulsive design response spectrum acc.

Ac = convective des. response spectrum acc.

WT = total tank wt. including operating liquid

Wc = sloshing liquid wt.

FE (V)

HLL

Overturning Moment by Earthquake

Shell Pressure

MP = Overturning moment by earthquake

shell pressure, (Ton-m)

= Ringwall or slab moment (API 650,

App. E)

MP = sqrt [(Vi * Xi)2 + (Vc * Xc)2]

Where:

Vi = impulsive base shear

Vc = convective base shear

Xi, Xc = moment arms

API 650, Appendix E Method:

Overturning Moment by Earthquake

Bottom Pressure

MPB = Overturning moment by earthquake

bottom pressure, (Ton-m)

Note: This is a Japanese caln method (i.e. Shoubou Hou Tokutei Okugai). This method

is related to DW1 (bottom plate pressure) at

earthquake condition.

Overturning Moment by Earthquake

ME = Total Overturning moment by

earthquake, (Ton-m)

ME = MP + MPB

ME

Increased Line Load

T = Increased line load by overturning

moment due to earthquake shell

pressure, (Ton/m)

T = MP / (pi * D2 / 4)

where:

D = tank inside diameter

DW1

HLL

Pressure at Base Plate, DW1

@ Operating Condition (Liquid Height = HLL):

1. Empty @ No Pressure: DW1 = Bottom plate wt per unit area

2. Full Liquid @ No Pressure: DW1 = Equation 1 + Static head pressure

3. Empty @ Design Pressure: DW1 = Equation 1 + Design pressure

4. Full Liquid @ Design Pressure: DW1 = Equation 2 + Design pressure

= Equation 3 + Static head pressure

5. Full Liquid @ Test Pressure: DW1 = Equation 2 + Test pressure

@ Hydro & Pneumatic Test (Water Height = Tank Height):

@ Earthquake Condition:

----1 ----4 ----3 ----2 ----5

----6

----7

6. Maximum:

7. Minimum:

This value is calculated in consideration of vertical acceleration and MPB. Weight of bottom plate and liquid are factors based on the acceleration.

W1 W1

Loads Along the Shell, W1

@ Operating Condition (No Wind):

1. Empty @ No Pressure: W1 = [(WE + Insulation wt Bottom plate wt) * (1/pi*D)] + [Live Load * (pi*D)]

2. Full Liquid @ No Pressure: W1 = Same as Equation 1

3. Empty @ Design Pressure: W1 = Equation 1 [Design pressure * (pi*D)]

4. Full Liquid @ Design Pressure: W1 = Same as Equation 3

@ Hydro & Pneumatic Test (No Wind):

----1 ----2 ----3 ----4 ----5

----9 ----8 ----7 ----6 ----10 ----11

5. Full Liquid @ Test Pressure: W1 = [(WE Bottom plate wt) * (1/pi*D)] - [Test Pressure * (pi*D)]

Note: Live Load = 1.2 kPa

W1 W1

Loads Along the Shell, W1 (cont)

@ Operating Condition (Max. Wind):

6. Empty @ No Pressure: W1 = Equation 1 + [MW / (pi*D2/4)]

7. Full Liquid @ No Pressure: W1 = Same as Equation 6

8. Empty @ Design Pressure: W1 = Equation 6 [Design pressure * (pi*D)]

9. Full Liquid @ Design Pressure: W1 = Same as Equation 8

@ Hydro & Pneumatic Test (50% of Max. Wind):

----1 ----2 ----3 ----4 ----5

----9 ----8 ----7 ----6 ----10 ----11

10. Full Liquid @ Test Pressure: W1 = Equation 5 + [0.5 * MW / (pi*D2/4)]

@ Earthquake Condition:

11. Full Liquid @ Design Pressure: W1 = Equation 1 +

Increased line load, T [Live Load * (pi*D)]

Loads on Anchor Bolts, W2

W2 W2

@ Operating Condition (No Wind):

1. Empty @ No Pressure: W2 = 0 ----> No uplift internal pressure

2. Full Liquid @ No Pressure: W2 = Same as Equation 1

3. Empty @ Design Pressure: W2 = {[WE + Insulation wt Bottom plate wt] + [(Live Load - Uplift due to internal pressure) * (pi*D2/4)]} / No. of Anchor Bolts

4. Full Liquid @ Design Pressure: W2 = Same as Equation 3

@ Hydro & Pneumatic Test (No Wind):

5. Full Liquid @ Test Pressure: W2 = {[WE Bottom plate wt] - [Uplift due to test pressure * (pi*D2/4)]} / No. of Anchor Bolts

----6

----1 ----2 ----3 ----4 ----5

----9 ----8 ----7 ----10 ----11

12----

13----

Note: 1. If weight resisting uplift is greater than uplift pressure,

W2 is zero.

Loads on Anchor Bolts, W2 (cont)

W2 W2

@ Operating Condition (Max. Wind):

6. Empty @ No Pressure: W2 = {[WE + Insulation wt Bottom plate wt] + [Live Load * (pi*D2/4)] - [4 * MW / D]} / No. of Anchor Bolts

7. Full Liquid @ No Pressure: W2 = Same as Equation 6

8. Empty @ Design Pressure: W2 = {[WE + Insulation wt Bottom plate wt] + [(Live Load - Uplift due to internal pressure) * (pi*D2/4)] [4 * MW / D]} / No. of Anchor Bolts

9. Full Liquid @ Design Pressure: W2 = Same as Equation 8

@ Hydro & Pneumatic Test (50% of Max. Wind):

10. Full Liquid @ Test Pressure: W2 = {[WE Bottom plate wt] - [Uplift due to test pressure * (pi*D2/4)] - [0.5 * 4 * MW / D]} /

No. of Anchor Bolts

----6

----1 ----2 ----3 ----4 ----5

----9 ----8 ----7 ----10 ----11

12----

13----

Loads on Anchor Bolts, W2 (cont)

W2 W2

@ Earthquake Condition:

----6

----1 ----2 ----3 ----4 ----5

----9 ----8 ----7 ----10 ----11

12----

13----

11. Full Liquid @ Design Pressure : W2 = {[WE + Insulation wt Bottom plate wt] - [Uplift due to internal pressure * (pi*D2/4)]

- [4 * ME / D]} / No. of Anchor Bolts

@ Uplift for Internal Pressure (API 650, F.7.5):

12. No Wind Condition : W2 = {[WE + Insulation wt Bottom plate wt] - [1.25 * Uplift due to test pressure * (pi*D2/4)]} / No. of Anchor Bolts

13. Max. Wind Condition : W2 = {[WE + Insulation wt Bottom plate wt] [1.5 * Uplift due to design pressure * (pi*D2/4)] [4 * MW / D]} / No. of Anchor Bolts