hdgasa03-2006 hdg and duplex corrosion protection

7/31/2019 HDGASA03-2006 HDG and Duplex Corrosion Protection

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HOT DIP GALVANIZING AND DUPLEX CORROSIONPROTECTION SPECIFICATION

This Specification has been prepared for the use of manufacturers, contractors, engineers and others involved in the design or appl ication ofDuplex Systems. I t has been compiled from work carried out by a co-ord inating committee drawn from industry. Whi le recognis ing that each system must be designed and appl ied to meet part icu lar c ircumstances,

the committee assumes no responsibil i ty or l iabi l i ty of any kind, in connection wi th this Specification or i ts use by any person or organisation

and makes no representation or warranties of any kind hereby.

Hot Dip Galvanizers Association Southern Africa

Quality House, Unit U4, St Christopher Road, St Andrews,Bedfordview

PO Box 2212, Edenvale, 1610

Tel: (011) 456-7960 Fax: (011) 454-6304


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ENGINEERING SPECIFICATION

HOT DIP GALVANIZING ANDDUPLEX CORROSION

PROTECTION

APPROVED AND ACCEPTED BY

POSITION DATE SIGNATURE

1.

2.

3.


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DISTRIBUTION LIST

COPY POSITION COMPANY NAME DATE

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

13.

14.

15.

16.


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TABLE OF CONTENTS

1.APPROVED HOT DIP GALVANIZER

2.QUALITY STANDARDS

2.1 QUALITY CONTROL

2.2 COATING REPAIRS

3.QUALITY SURVEILLANCE

4.DATA BOOK

5.HANDLING AND STORAGE

5.1 HANDLING

5.2 LOADING

5.3 UNLOADING

5.4 COVER

5.5 STACKING

6.SITE REPAIRS

7.DUPLEX COATING (HOT DIP GALVANIZING PLUS PAINT)

8.SELECTION OF PAINT SYSTEM FOR DUPLEX PROTECTION

9.QUALITY CONTROL AND SURVEILLANCE

10.RELATED DOCUMENTS


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1. APPROVED GALVANIZER

A Sou th African Bureau of Standards (SABS) approved company shal lundertake a ll hot d i p galvanizi ng , wh ich i s an accredi ted member o f the Hot

Dip Galvanizers Association Southern Africa.

2. QUALITY STANDARDS

The hot d ip ga lvanized coating shal l conform in every respect to the standards conta ined in the South African Nationa l Standards, SANS 1 21 ( ISO 1 461 ) and SANS 32 (En 1 0240) , Hot D ip Galvanizi ng speci fi ca tion for p roducts otherthan continuously ga lvanized sheet and wire.

2.1 QUALITY CONTROL

The hot d ip gal vani ze r shal l p rovi de a q ual ity managemen t pl an deta il ing

inspection procedures, wh ich wil l in cl ud e i nspecti on of steel prior toga lvan iz ing , i n l ine i nspection during surface preparation and ga lvan iz ing and

fi na l i nspection p rior to despa tch . Where fabri ca tion defects a re i denti fi ed prior to ga lvan izing, e .g . burrs , poor welding o r excess ive weld spatter, such

components shal l be p laced on ho ld and a non-conformance report submitted to the fabricator.

Double end d ipp ing sha l l be permi tted provided that i t wi l l not resu l t

i n d istortion o f the product and an acceptable surface fin ish o f thecoating is achieved.

Bolts , nu ts and o ther fastening devices sha l l be hot d ip ga lvan ized.

Zi nc el ectropl ati ng (el ectro-gal van izin g) i s u nacceptabl e. Al lfasteners shal l be suppl ied by a SABS approved manufacturer .

High tensi le fasteners from g rade 1 0 .9 and above sha ll be hot d ip

gal vani zed i n con formance to a code of practi ce (SANS 1 0094, annex B). The hot d ip galvanizer shal l issue a certificate of

compliance with this requirement.

2.2 COATING REPAIRS

Any coati ng repa irs undertaken on the gal vanizers prem ises or later on si te,e.g. touch up of smal l-uncoated surfaces (black spots), sha l l be str ictly l imi ted both i n d imension and quanti ty as s tipu la ted i n the re levant SANS 1 21 (SABS ISO 1 461) specification.

Uncoated areas and defects shal l be repaired by abrading surfaceswi th 80 g ri t sandpaper a nd pa in ti ng wi th Galvpatch or approved equal twi n pack zi nc ri ch epoxy pai nt, a ch ievi ng a n 5mm overl ap


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and to a minimum thi ckness of 30m above the mean coati ng th ickness speci fied i n terms o f SANS 1 21 ( ISO 1 461 ) . The repa ired

su rfa ce shal l n ot be a ccepted or d espatched u nti l th e repai red surface coating has cured.

Where coating defects exceed the specified permissible l imit, which qual i fies for touch-up repairs after ga lvanizing, affected i tems shal l

be rejected and regalvanized.

F i n a l I n s p e c t i o n :

After the final inspection has been completed satisfactori ly, thega lvanizers inspectorate shal l i ssue a certi ficate stating that the appl ied coating conforms to the requ i rements o f SANS 1 21 ( ISO 1 461 ) o r SANS

32 (En 1 0240) .

3. QUALITY SURVEILLANCE

3.1 The cl ient may employ an independent technical ly qual ified o rganisation to carry out Qua l ity Surve il lance o f the work on i ts beha lf.

I n the event of d ispute, the decision of The cl ient shal l be final .

3.2 For the purpose of carrying out qual ity survei l lance, The c l ient or i ts QA/ QC Consu l tant sha l l be g ranted access to any part of the galvanizers premises re levant to the work being carr ied out, a t any reasonable time. The galvanizer sha l l p rovide , a t h is own cos t, any equ ipment or l abournecessary to ga in access to surfaces wh ich a re coated , to be coated or

are in the process of being coated.

3.3 The c lient may remove any reasonable samples of materia ls to be used i n the coa ti ng app li ca tion . Re jection of the samp le wi ll p lace a hold on the use o f material o f the same batch number and may lead to re jection o f a ll that batch of material and the reworking o f any components thathave already been coated with rejected material .

3.4 The cl ient may ca rry ou t reasonable destructi ve tests to a scerta in

compl iance wi th the speci fication . The contractor to the satisfaction o fThe c l ient a t no addi tional cost sha l l repair areas thus damaged.

3. 5 The cost of qu al ity su rvei ll ance wil l be borne by The cl ien t, except

where surve i llance resu l ts i n re jection o f the work or when notice by thecon tractor resu l ts i n a fru itless tri p, i n wh ich case the contracto r sha ll

carry the cost of survei l lance.

3.6 The inspector sha l l complete a report a t each visi t. A copy o f the reportsha l l be g iven to the ga lvanizing company.


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4. DATA BOOK

4.1 Upon completion o f the works , the contractor sha l l provide The cl ient wi th a Data Book conta ining a l l the re levant Qua l ity Contro l documents

and records perta in ing to the works.

4.2 The contracto r sha ll submit one copy o f the Data Book to The cl ient and keep one copy for h is own records.

5. HANDLING AND STORAGE

The fol lowing precautions shal l be taken for storage of coated i tems.

5.1 HANDLING

All coated componen ts shal l be han dled using soft sl ings or special lyposi tioned l i fting points provided for such handling.

5.2 LOADING

All hot dip galvanized and dupl ex coated componen ts to be transported

shal l b e l oaded on su itabl e d unnage a nd l ashed to a voi d chafi ng ands teel to s teel contact. P lastic Spaghetti s trips must be used to protect

smal ler i tems of s teel and ang les (5mm spaghetti p lasti c coi l ). Coa tedsteel shal l be secured on the truck preferably wi th nylon secur ing straps.

Where chai ns must be u sed , ru bber i nserti on pa ds must be pl aced between the coated steel and chains at a l l contact points.

5.3 UNLOADING

Off-loading at si te shal l be conducted using the same care and precautions as required for on loading.

Components shal l not be t ipped off the transportation.

5.4 COVER

Coated i tems shal l be stored under cover where possible.

I tems n ot stored u nder cover shal l be stored i n su ch a manner a s toavoid retention of water and al low good circulation.I tems shal l be stored on timber or on trestles fi tted wi th timber to ra ise the product to at laest 500mm off the ground.


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5.5 STACKING

I tems sha l l be s tacked using timber packag ing or o ther approved meansto avo id coa ti ng-to-coa ti ng con tact. Suffi cien t bari ng a rea of packing

shal l be used to avo id damage to coatings.

6. SITE REPAIRS

Mod ifi ca ti ons, transporta ti on a nd e recti on damage, shal l be repa ired byabradi ng wi th 80 g ri t sand paper a nd pa in ti ng wi th Galvpa tch or approved equal twin pack zi nc ri ch epoxy paint, ach ieving an overlap o f 5mm on to thesurrounding sound zi nc coa ti ng and to a m in imum th ickness o f 30m above the mean coating thickness specified for the hot d ip ga lvanized coat ing. Steel shal l not be accepted unti l the repaired surface has cured.

Black steel u ti l ised in modification wi th ga lvanized steel sha l l be abrasive b last

cl eaned to S tandard Sa 2 to obta in a su rface p rofi le of 40 to 70 m icrons. Once the surface profi le has been inspected and certi fied , app ly z inc thermal

sprayed coating to a minimum thickness of 1 20m.

Alternativel y, bl ack steel uti l ised in mod ificat ions with hot d ip gal vanized steelsha l l be abrasive b last cleaned to Standard Sa 2 per In ternationa l Standard

ISO 850 /1 1988 to ob ta in a su rface profi le of 4 0 to 70 m icrons. Once thesu rface prepa ra ti on has been i nspected and certi fi ed , a pply one coa t of

Galvpatch or approved equal twin pack zi nc ri ch epoxy paint, ach ieving anoverlap o f 5mm onto exi sti ng sound hot d ip galvanized coati ng where b lack

s teel i s we lded to hot d ip ga lvan ized components . Dry fi lm th ickness sha l l be30m above the mean coating th ickness speci fied for the hot d ip ga lvan ized coating.

Where s i te modifications of a hot d ip ga lvanized surface is required, a l l t races

of the hot d ip galvanized coating shal l be ground off prior to welding. Removal of the z inc coating from surfaces to be welded, is necessary in order

to prevent possi ble weld metal embri ttl emen t or zi nc resi due i ncl usi ons.

APPROVED COATINGS

Brand Name Manufacturer / Supplier

Primer To be approved by the engineer

Galvpatch Hot Dip Galvanizers Association S.A.


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7. DUPLEX COATING (HOT DIP GALVANIZING PLUS PAINT)

Th is speci fi ca tion covers the painti ng o f hot d ip galvanized s teel o ther than

sheet and wi re . The requi rements for the painting of hot d ip ga lvan ized sheetare contained in document SEP / SAZ 51 1 Surface Preparation andPainting.

7.1 All hot d ip galvanized stee l to be pa inted shal l be certi fied asconforming to the required hot d ip ga lvanizing qual i ty standard, prior to painting.

7.2 Painting sh al l take pl ace as soon as possibl e after gal vanizing, preferabl y a t th e g al vani zi ng con tractor s prem ises. I f th is i s n ot

feas ib le for practica l reasons, painting on s ite i s acceptable , but sha l lbe in accordance wi th 7.3.

7.3 Code of Practice for Painting Hot Dip Galvanized Steel:

Painting procedures shal l comply wi th the requi rements conta ined in

SAHDGA standard 1 990, Specification for the PerformanceRequi rements o f Coating Systems and speci fication 01 -1990, Code o f

Pract ice for Surface Preparation and Appl ication of Organic Coatings.

Adequate su rface preparation can be achieved by way of chem ica lcl ean ing . Su rface sweep bl astin g is, however, th e preferred

procedure.

W a r n i n g : Sweep blasting shal l be undertaken strictly in

accordance wi th the procedures as specified in the code of pract ice, with parti cu lar reference to the sel ection of the appropriateabrasive , b lasti ng nozzle p ressure and ang le o f deflection of theblasting media. Fai lure to do so wil l result in damage of the

galvanized coating.

8. SELECTION OF PAINT SYSTEM FOR DUPLEX PROTECTION

9. QUALITY CONTROL AND SURVEILLANCE

Al l relevant requiremen ts provi ded in Specification SEP/SAZ/51 1 (SurfacePreparation and Painting) sha l l a lso app ly to Duplex coatings. (pa inting o f hot

d ip ga lvanized steel) .


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10. RELATED DOCUMENTS

Al l nat ional and international standards referred to in th is documen t shal l formpart of this specification. Where reference is made to a code, specification ors tandard the reference sha l l be taken to mean the la test edi tion o f the code, speci fi ca ti on or standard , i ncl ud ing a ddenda , supplemen ts a nd revi si ons

thereto.

10.1 SOUTH AFRICAN NATIONAL STANDARDS (SANS)

SANS 1 21 (ISO 1 461 ) Hot D ip Galvani zed zi nc coa ti ngs (other than continuously zinc-coated sheet and wire).

SANS 32 (En 1 0 240) for H ot Di p Gal vani zed Pi pe produced on an automatic or semi-automatic tube plant.

10.2 INTERNATIONAL ORGANIZATION FOR STANDARDIZATION

ISO 9002 Qual i ty Management System.

10.3 SOUTH AFRICAN HOT-DIP GALVANIZERS' ASSOCIATION

No HDGASA 01-1 990 Code o f Practice for Surface Preparation and

App l ication of Organic Coat ings

No HDGASA 02-1 990 Specification for the PerformanceRequirements of Coating Systems

Weber-Rei l ly soluble salts test method: Test for soluble sa lts .

hdgasa03-2006 hdg and duplex corrosion protection

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