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API 2000 - SEVENTH EDITION, MARCH 2014 ANNEXURE - F , "Guidance for Inert gas inert gas blanketing of tanks for flash back protection" LEVEL - 3 (No additional protection against flame propagation from outside to the inside of tank is required) Required flow rate Volume of reserve inert gas Tank Dimensions: Dia Height Slope of cone roof Site Latitude

= = = =

In Flow rate

=

398 m3/hr

Out Flow Rate Operating Pressure Operating Temperature

= = = lin

440 m3/hr 3 kPag 65 °C

wall thickness of insulation inside heat transfer co-efficient thermal conductivity of insulation Reduction factor for insulation C Factor for Lattitude

22 13 12 23-24 °

1

5.00E-02 m

h λin

4 W/(m2.K) 0.043 W/(m.K)

Rin

0.177 6.5

Tank Volume

= Vtk

Out flow rate

Vpe

365.95 Nm3/hr

Required Nitrogen flow rate

=

591.12 Nm3/hr

Volume of reserve inert gas

=

606.9452 m3

@ 3 kPag, 65°C

Volume of reserve inert gas

=

79.60567 m

@ 600 kPag, 25°C

Required Outbrething flowrate Required Outbrething flowrate for PVRV Required vaccum capacity for PVRV Required Outbrething flowrate for SAPCV

= = = =

520.0629 Am3/h Air 420.0508 Nm3/hr Air 570.7385 Nm3/hr of Air 435.0526 Nm3/hr of N2

5057.88 m3

3

Emergency Relieving Reference API 2000 : Section 3.3.3.3 : Fire Relief Requirements

Wetted surface area Q F L T M

631.7115 m2 4,129,700 W 0.15 1519000 j/kg 338.15 K 30.33

Considering hexane 631.7115 m2 208.2 1 334900 j/kg 288.75 K 86.17

q

1234.486

41200.84 6427.331

Table 1 — Y-factor for various latitudes Latitude Y-factor Below 42° 0.32 Between 42° and 58° 0.25 Above 58° 0.2

Table 2 — C-factors Latitude

°C Below 42° Between 42° and 58° Above 58°

C-factor for various conditions Vapour pressure Hexane or similar Higher than hexane, or unknown Average storage temperature °C