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Slide 1

API 575

Guidelines and methods for inspection of existing

atmospheric and low-pressure storage tanks

Section 4 gives general

information on various

types of tanks and their

applications

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Slide 2

TYPES OF TANKS

Fixed roof

2 MAIN TYPES:

Floating roof

Non-volatileproducts

Volatile

products

ATMOSPHERIC

(API 650) =< 2.5 psi

LOW PRESSURISED

(API 620) 2.515 psi

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Slide 3

FIXED ROOF DESIGNS

Fixed cone

roof

Umbrella roof

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Slide 4

FIXED ROOF DESIGNS

A more extreme design of fixed roof is the domed or

Geodesic dome type

Aluminium Geodesic dome may be self-supporting

(doesnt need internal support columns etc)

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Slide 5

FLOATING ROOF DESIGNS

Floating roof used for volatile/inflammable contents

Roof moves up and

down with the fluid level

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Slide 6

FLOATING ROOF

Floating roof can be pan, pontoon or

double-deck type (see fig 8 of API 575)

Contents

Roofseals

Pontoon floatingroof

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Slide 7

FLOATING ROOFS

Pontoon typePan type

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Slide 8

ROOF DRAINS

Floating roof types need articulated drains to

drain rain water off the roof

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Slide 9

ROOF SEALS

Vapour seals are

required between thefloating roof and the

shell wall

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Slide 10

ROOF SEALS

Simplest type is the mechanical strip wiper seal

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Slide 11

OTHER ROOF SEAL TYPES

Mechanical

shoe seal

Double strip

seal

Resilient or foam-

filled (tube-type) seal

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Slide 12

ADDITIONAL DOME ROOF

Contents

Floating roof tanks may be fitted with an additional dome

roof to keep out the weather and prevent vapour release

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Slide 13

LOW PRESSURE TANKS

These have more advanced pressure-retaining

shapes

These are knuckle-edge dome designs

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Slide 14

LOW PRESSURE TANKS

Most modern ones are based on spheres or are fully

spherical

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Slide 15

TYPES OF TANKS :SUMMARY

BEFORE PROCEEDING FURTHER

1.Make sure that you understand the preceding slides,showing various types of storage tanks

2.Identify the types shown in the slides in API 575section 4 and read the commentary that accompanies

them. Make sure that you highlight/underline any key

technical points that could form closed-book examquestions