Protection of petroleumor gas tanks

L I G H T N I N G P R O T E C T I O N S P E C I F I C A T I O N

Protection of petroleumor gas tanks

using a

PREVECTRON®

early streamer emission

lightning conductor

GENERAL

1�The lightning protection system shouldbe in full compliance with French lightningprotection standard NF C 17-102(Protection of structures and open areasagainst lightning using Early StreamerEmission air terminals).

2�To ensure an effective system and satisfac-tory long term performance, all fittings needto be mechanically robust and provide goodcorrosion resistance in conditions of 50° Cand 95% relative humidity.

3�All materials used should be suitable forlightning protection installations.

AIR TERMINAL

1�The air terminal should be of thePREVECTRON® Early Streamer Emission(E.S.E.) type which is equipped with a lowerseries of energy collecting electrodes andan upper series of spark-generatingelectrodes. The triggering device ofthe E.S.E. air terminal is sealed in astainless-steel housing fixed at thecentre of its central rod.

2�The air terminal should be fixed at the topof a free-standing ground mounted supporttower within the area to be protected.The height of the tower would be dependenton the level of protection and the protectionradii required. Guy wires must not be used.

3�The tower should be installed outside thesafety area and a minimum distance of 8metres from the tank must be respected.One installation may protect several tanks.

USING A PREVECTRON®

EARLY STREAMER EMISSION (E.S.E.)LIGHTNING CONDUCTOR

PROTECTION OFPETROLEUM OR GAS TANKS

DOWN CONDUCTOR

1�The down conductor should be highconductivity round or flat solid copperconductor with minimum size 50 mm2.It should be fixed to the structure of thetower by means of 3 fasteners per metre.

2�The down conductor should be connectedto the air terminal by a metallic adapterlocated on the E.S.E. air terminal.It should then run down the tower takingthe shortest direct route down to theearth termination network, avoiding anysharp corners, thereby providing a lowimpedance path from the air terminalto its earth termination system.

3�A 6 digit Lightning Flash Counter may beinstalled on the tower in order to countthe actual lightning strikes on the E.S.E.air terminal.

4�The base of the down conductor shouldbe protected from accidental knocks andother damage by means of a 2 metrestainless-steel protection sheath fixedto the tower.

5�A test clamp should be provided at thebottom of the tower in a P.V.C or concreteinspection pit so that the down conductormay be disconnected from the earthtermination and regular checks of the earthtermination resistance be carried out.

EARTH TERMINATION SYSTEM

1�The down conductor should be connectedto its own earth termination system usinga crow-foot earth termination. The crow-foot termination is made of conductors ofthe same cross-sectional area as the downconductor of the installation and arrangedin a crow-foot fashion (three 7 to 8 metrelong conductors buried horizontally).A copper-covered steel earth rod shouldbe added at the end of each copper run.

2�The earth termination system shouldbe orientated away from storage tanks.

3�The resistance value of the earth terminationsystem should be 10 Ohms or less.

4�Each earth conductor and rod connectionshould be housed in a proprietary concreteor P.V.C pit in order to facilitate inspection.The pit should be complete with a lid andthe assembly should be installed flush withground level.

5�The lightning conductor earth terminationsystem must then be connected to thegeneral earthing network of the site in orderto achieve an equipotential earth network.This connection should be equipped with adisconnecting clamp housed in a concreteor P.V.C inspection pit.

Conforming the international standard CEI 61643-11and the French standard NF EN 61643-11, the installation of a type 1 overvoltage

arrester (DGV) is now mandatory for all structure equipped with a lightning air terminal.

5

2

6

8

4

10

7

11

3

9

Protection ofpetroleum or gas tanks

The

com

pone

nt p

arts

sho

wn

on t

he le

ft a

re g

iven

by

way

of

exam

ple

only

.Th

is d

raw

ing

is n

ot t

o sc

ale.

- IV

OI’A

RT

- LIL

LE/F

RA

NC

E -+

33

(0)3

28

52

67

54

- P

hoto

: In

dele

c - D

OC

03

3.V

EN0

1

�

�

�

�

�

�

�

�

�

�

1

�

1 Prevectron®2 S 6.60 ref: 12432 Self standing mast ref: 20633 Clamping collar ref: 60584 Copper conductor ref: 50015 Digital Lightning Flash Counter ref: 80116 Protection sheath ref: 70147 Inspection housing ref: 70528 Test clamp ref: 7001B9 Copper earthing ref: 7021

10 Earth rod ref: 703011 Rod-to-conductor clamp ref: 7039

Corporate Headquarters and Export Division61, chemin des Postes - 59500 DOUAI - FranceTel: +33 327 944 952 - Fax: +33 327 944 955www.indelec.com - e-mail: contact@indelec.com

USING A PREVECTRON® EARLY STREAMER EMISSION (E.S.E.) LIGHTNING CONDUCTOR