Imo pspc - things to know

Imo pspc - things to know ! Giáo trình pspc cho đăng kiểm viên của đăng kiểm germanischer lloyd

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IMO PSPC – Things to know !

Surveyors

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• Current status concerning corrosion protection at GL

reference to coating

Objectives

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Rules and Guidelines GL

IMO PSPC

No 3 Seminar IMO PSPC

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IMO PSPC

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• Based on current Rules for Classification and Construction Part 0 and Part 1 of GL

• Further information in GL‘s Guidelines for Corrosion Protection and Coating Systems

• Current areas that have to be coated:

• Seawater Ballast Tanks

• Cargo Holds of Bulk Carriers

• Outer Hull for Ships intended to be assigned with the class notation IW

• ItS Corrosion Protection Part I, Chapter 2, Section 1 A 7

Current Status Corrosion Protection

at GL

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GL Rules

• Mandatory requirements in GL

“Rules for Classification and Construction” I – Part 1, Chapter 1, Section 35 “Corrosion Protection”:

• General Instructions

• Hollow Spaces

• Combination of Materials

• Fitting-Out and Berthing Periods

• Corrosion Protection of Ballast Water Tanks

• Corrosion Protection of Cargo Holds

•

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• Water Ballast Tanks in all ships:

Approved coating systems (hard coatings) with min DFT

of 250µm.

Specific areas to be coated with suitable coating, min DFT of 250µm.

GL Rules - Requirements of

Corrosion Protection

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Approval Procedure

• Applied coatings to be approved by GL

• Current list obtainable in intranet and internet:

www.gl-group.com Approval Finder Approval Finder Type Approvals "Coatings for Seawater Ballast Tanks Approved by Germanischer Lloyd"

• Coating Specification to be approved by GL Corrosion Protection Dept according to GL Rules

GL Rules - Corrosion Protection of

Ballast Water Tanks (2)

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Requirements of Corrosion Protection

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• Coating shall be applied acc to approved coating specification,

manufacturer’s recommendations

• During application, spot checks shall be carried out by the Surveyor

• In case of deviations all parties involved shall be informed

• During final inspection the coating shall be checked at random with respect to surface irregularities, thickness

• Coating protocol shall be verified with respect to completeness and required signatures

Current Status Supervision

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IMO PSPC

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IMO PSPC

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• An international coating standard for ballast water

tanks on ship newbuildings

Maritime Organization (IMO)

What is the IMO PSPC?

Seminar IMO PSPC No 13

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Contents of the IMO PSPC

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IMO and IACS

Enforcement of the IMO PSPC

Ballast water tanks (PSPC BWT)

is mandatory via amendments

SOLAS-accepts as Recognized Organization develops

is mandatory via CSR

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IMO PSPC Ballast Water Tanks

IMO SOLAS – Convention

IACS Classification Societies

IMO PSPC BWT

IACS Common Structural Rules

implement demand

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Related Documents

• For vessels built under the Common Structural Rules

• Classificatory vessels

• For all vessels for which the IMO PSPC is mandatory

• SOLAS vessels

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The IMO PSPC

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Technical Standard

Documentation/

Verification standard

Testing standard

Definition of Technical Requirements

• Verification by Coating Inspector

• Documentation in form of

a ‘Coating Technical File’

International Test for the pre-qualification of coating systems

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Technical Standard

Documentation/

Testing standard

Definition of Technical Requirements

International Test for the pre-qualification of coating systems

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Type Approval of the Coating System

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Technical standard

Documentation/

Testing standard

Primary surface preparation

(PSP) Secondary surface preparation

(SSP) Design of the coating system

Miscellaneous

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Miscellaneous

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for coating“ (ISO 12944-4).

matter which deteriorates the adhesion of the coating.

corrosion - supporting substances.

No 25

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PSPC Requirement

Primary surface preparation

Blasting and Profile (ISO 8501-1; ISO 8503-1/2)

• Sa 2 ½; with profiles between 30-75 µm

• Blasting shall not be carried out when:

• the relative humidity is above 85%; or

• the surface temperature of steel is less than 3°C above the dew point

• Checking of the steel surface cleanliness and roughness profile

shall be carried out at the end of the surface preparation and before the application of the primer, in accordance with the manufacturer´s

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Overview of Methods

n.n.

Surface Preparation

Mechanical Methods Chemical Methods

Blast Cleaning

Pickling (Be)

n.n.

Inductive Cleaning Flame Cleaning

(Fi)

Dw Hand-power Tools

(St, PSt, PMa) Grit blasting

(Sa, PSa)

Water Jetting Dw

Thermal Methods

Grit + HP Water Jetting

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Grit blasting

pneumatically accelerated and forcefully directed against a surface

from the materials surface and condition the surface for subsequent finishing

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ISO 8501-1 – Preparation grades

Surface preparation grades contain two informations:

1 Method for surface preparation

• method described in 8504-2

• St Hand- and power-tool cleaning

• method described in ISO 8504-3

• Ma Machine abrading (localized)

• Wa High-pressure water jetting

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Blast cleaning

Hand and power tool cleaning

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ISO 8501-1 – Examples

 Jotun

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ISO 8501-1 – Rust grades

Grade

A Steel surface largely covered with adhering mill scale but

little, if any, rust

B Steel surface which has begun to rust and from which the

mill scale has begun to flake

C

Steel surface on which the mill scale has rusted away or from which it can be scraped, but with slight pitting visible under normal vision

D Steel surface on which the mill scale has rusted away and

on which general pitting is visible under normal vision

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ISO 8501-1 – Rust grades

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Abrasives - Metallic

Steel grit

Stainless steel shot

Steel cut wire Steel shot

Chilled-iron shot Chilled-iron grit

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Abrasives – non-metallic

Glass beads

Duroplast

Ceramic beads Corundum

 Würth Strahlmittel

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ISO 8501-1 – Abrasive effects

Original steel (rust grade C)

High-carbon cast-steel shot (low

hardness) Steel grit (low hardness) Steel grit (high hardness)

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Summary

• Initial condition of the surface

• Abrasive material and shape

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ISO 8503-1/2 - Roughness

Sa 2 ½ shot-blasting

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ISO 8503-1/2 – Roughness

Influences

The roughness profile is mainly influenced by:

• Abrasive material – round, sharp-edged

• Allocation of the abrasive material sizes

• Impacts per area

• Blasting pressure

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30-50 mic

50-70 mic

Shot-Blasting Grit-Blasting

Average peak to valley profile

Maximum peak to valley profile

5 min-max readings over a defined distance

~ R y5

IMO PSPC!!

Definition

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Definition:

• Rmax is approximately 6 times Ra

• Rz/Ry5 is approximately 4-6 times Ra

• Definition of roughness in the IMO PSPC is Rz/Ry5

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ISO 8503-1/2 - Roughness

ISO comparator

Microscope

Assessment methods

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(proper roughness increases the surface by 2-3 times)

roughness

Rmax)!

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Blasting and Profile (ISO 8501-1; ISO 8503-1/2)

• Sa 2 ½; with profiles between 30-75 µm

• Blasting shall not be carried out when:

• the relative humidity is above 85%; or

• the surface temperature of steel is less than 3°C above the dew point

• Checking of the steel surface cleanliness and roughness profile

shall be carried out at the end of the surface preparation and before the application of the primer, in accordance with the manufacturer´srecommendations

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ISO 8502-4 - Climatic conditions

of air must be cooled, at constant barometric pressure, for water vapor to condense into water

temperature is a maximum of 2,5°C away from the air temperature!

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face

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Example

Surface temperature for coating:

18.0°C + 3°C = 21°C

 ISO

Condensation

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Seminar IMO PSPC No 51

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How often is to be checked?

Table 6.2 in the IMO PSPC

• The surface temperature of steel, the relative humidity and the dew point shall be measured and recorded before the blasting process starts and at times of sudden weather changes

• Measurements according to the inspection agreement

(section 3.2 in the IMO PSPC)

• If it is an automated system it may be monitored instead of

measuring every plate as long as it is noted in the shipyard procedure and meets the requirements in the IMO PSPC (IACS

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Water soluble salt limit equivalent to NaCI (ISO 8502-9)

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ISO 8502-6 – Salt determination

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ISO 8502-6 – Salt determination

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µS/cm µS/cm

8502-6 - Field method for soluble salts

Condumetric measurement 8509-9 (Bresle Kit)

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• How many measurements of salt shall be required during primary surface stage?

• As agreed in the Inspection Agreement (Sect 3.2 IMO PSPC)

• at least one (1) reading per block/section/unit or one (1) reading per plate in case of manually applied shop primer

• Measure salt and remove before going into shot blasting or

• Have shipyard procedures to check occasional readings after shot blasting

• Quality Assurance System which should include a monthly test

• Pay attention if you order shop primed plates from a supplier (specification of how and how often salt is measured)!

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Miscellaneous

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Secondary surface preparation

Steel condition (ISO 8501-3)

• The steel surface shall be prepared so that the coating selected

can achieve an even distribution at the required NDFT and have

an adequate adhesion by

− removing sharp edges

− grinding weld beats

− removing weld spatter and other surface contaminant

• Edges shall be treated to a rounded radius of minimum 2 mm, or

subjected to three pass grinding or at least equivalent process before painting

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• Edges mean all sharp edges (non-radiused or with a radius less than 2mm)

• Includes thermally and mechanically edges

• All sharp edges (non-radiused or with a radius less than 2mm) are subject to edge grinding

• An example of an equivalent process is a dedicated edge grindingmachine which will provide the profile equal to radius 2mm or three pass grinding by a single pass (IACS position)

Edge grinding

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Edge grinding

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ISO 8501-3 - Secondary Surface Preparation

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ISO 8501-3 - Summary

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Surface treatment (ISO 8501-1)

• Sa 2 ½ on damaged shop primer and welds

• Sa 2 removing at least 70% of intact shop primer, which has not

passed a pre-qualification

• If the complete coating system comprising epoxy-based main

coating and shop primer has passed a pre-qualification , intact shop primer may be retained provided the same epoxy coating system isused The retained shop primer shall be cleaned by sweep blasting, high-pressure water washing or equivalent method

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Surface treatment (ISO 8501-1)

• If a zinc silicate shop primer has passed the pre-qualification as part

of an epoxy coating system, it may be used in combination with other certified epoxy coatings, provided that the compatibility has been confirmed by the manufacturer by the test in accordance with 1.7 of appendix 1 to annex 1 without wave movement

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Surface treatment after erection (ISO 8501)

• Butts St 3 or Sa 2 ½ where practicable

• Small damages up to 2% of total area St 3

• Contiguous damages over 25 m2 or over 2% of the total area of the tank Sa 2 ½

• Coating in overlap shall be feathered

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ISO 8501-1/2 – Surface treatment

Preparation grades

Localized blast cleaning of previously coated surfaces

• P Sa 2 Thorough localized blast cleaning

• P Sa 2½ Very thorough localized blast cleaning

• P Sa 3 Localized blast cleaning to visually clean steel

Localized hand- and power-tool cleaning of previously coated surfaces

• P St 2 Thorough localized hand- and power-tool cleaning

• P St 3 Very thorough localized hand- and power-tool cleaning

Localized machine abrasing of previously coated surfaces

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P Sa 2½ Unsuitable coating

 ISO

Examples

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Surface treatment

Definitions

• Sweep blasting - very light (sand or other particle) blasting

− moving the nozzle fast and with low pressure

− removal of zinc oxide residues from the surface of zinc layers

• Power tool cleaning is not acceptable as an equivalent method except for small areas insufficiently treated by blasting

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total area: St 3 partial area: PMa (St 2)

Examples

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How to identify and calculate damaged areas over 25m^2 or over 2%

of the total area?

• Using the method of scribing matrix on the photos and calculating the area

• Damage is anything that in the opinion of the qualified coating inspector will prevent the coating from functioning

• Damage is considered to be in percentage of total area of tank

Surface treatment

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Profile requirements (ISO 8503-1/2)

• 30-75 µm, in case of full or partial blasting

• Otherwise as recommended by the coating manufacturer

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Dust (ISO 8502-3)

• Dust quantity is rating “1” for dust size Class “3”, “4”, or “5”

• Lower dust size classes to be removed if visible on the surface to be coated without magnification

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ISO 8502-3 – Dust assessment

IMO requires dust quantity „1“ for particle sizes „3“, „4“ und „5“.

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ISO 8502-3 – Dust assessment

• Result can be subjective

• Open for discussion

• Advice

• Choose hard to reach places to test

Tape Surface

Prob e compare

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• How to distinguish the size of dust with the naked eye?

• If you can see it is dust

• To the satisfaction of the coating inspector (one measurement is minimum per block)

• As per the inspection agreement under 3.2 in the IMO PSPC

Dust assessment

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Water soluble salts limit equivalent to NaCI after blasting/ grinding (ISO 8502-9)

• ≤ 50 mg/ m2 of sodium chloride

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Grease and oil

Assessment

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Grease and oil

Oily residues of the spray

used to avoid adherence of

welding sputters

Wetting test by water

Assessment

Tiêu đề	Imo pspc – things to know
Trường học	GL
Chuyên ngành	Corrosion Protection
Thể loại	seminar

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