G. K. WIRE INDUSTRIES LLC P.O.Box - 32820 , RAS AL KHAIMAH , United Arab Emirates RAK - Tel.(9717) 2447970 , FAX.( 9717) 2447515 Head Office, Dubai - Tel.(9714) 8872904 , Fax.(9714) 8816250 E-mail :
[email protected]
PROCEDURE FOR SURFACE PREPARATION AND HOT DIP GALVANIZING ON FABRICATED STEEL ITEMS
PROJECT:
EPC CPF Phase-1 al BADRA OIL FIELD
CLIENT:
Unger Steel Middle East FZE / PETROFAC
P.O NO.:
2013030011
LOCATION:
UAE
SUPPLIER:
G.K.Wire Industries LLC
DOCUMENT NUMBER:
LME- FCP-199-004
REV.
ISSUE DATE
PURPOSE OF ISSUE
PREPARED
APPROVED
01
05-09-2012
Customer Specific
N.B.Joshi
Dhananjay Joshi
02
05-09-2012
Customer Specific
N.B.Joshi
Dhananjay Joshi
G. K. WIRE INDUSTRIES LLC P.O.Box - 32820 , RAS AL KHAIMAH , United Arab Emirates RAK - Tel.(9717) 2447970 , FAX.( 9717) 2447515 Head Office, Dubai - Tel.(9714) 8872904 , Fax.(9714) 8816250 E-mail :
[email protected]
REVISION HISTORY: REV 00
DATE 05.09.2012
DESCRIPTION
Customer Specific
PREPARED BY
N.B.Joshi
.
DEFINITIONS :
Project:
EPC CPF Phase-1 al BADRA OIL FIELD
Contractor:
PETROFAC / Unger Steel Middle East FZE
Galvanizer:
G.K.Wire Industries LLC
APPROVED BY Dhananjay Joshi
G. K. WIRE INDUSTRIES LLC P.O.Box - 32820 , RAS AL KHAIMAH , United Arab Emirates RAK - Tel.(9717) 2447970 , FAX.( 9717) 2447515 Head Office, Dubai - Tel.(9714) 8872904 , Fax.(9714) 8816250 E-mail :
[email protected]
TABLE OF CONTENTS
1. 2. 3. 4.
SCOPE REFERENCE DOCUMENTS RESPONSIBILITIES PROCEDURE a. b. c. d. e. f. g. h. i. j. k. l. m.
Blasting & Cleaning the surface of steel articles Degreasing Water Rinse Pickling ( HCL Acid cleaning process ) Water Rinsing Process Flux coating process :( Zinc Ammonium Chloride – Triple Salt) Drying of Articles Zinc coating ( Hot dip Galvanizing ) of steel items Water Quenching process Cleaning & Grinding of galvanized Items Inspection Adhesion Repair
G. K. WIRE INDUSTRIES LLC P.O.Box - 32820 , RAS AL KHAIMAH , United Arab Emirates RAK - Tel.(9717) 2447970 , FAX.( 9717) 2447515 Head Office, Dubai - Tel.(9714) 8872904 , Fax.(9714) 8816250 E-mail :
[email protected]
1.
SCOPE This Process procedure intends to have the clear guidelines for Hot Dip Galvanizing of fabricated Steel products as per Order specification & Standard code specification requirements applicable to G.K.Wire Industries LLC.
2.
REFERENCE DOCUMENTS 1. BS EN ISO 1461:2009 – Hot Dip galvanized coatings on fabricated iron & steel articlesSpecification & test method. 2. ISO8501-1 - Preparation of steel substrates before application of paints and related “Rust grades and products preparation grades of uncoated substrates and of steel substrates after overall removal of previous coatings”. 3. ASTM A 123-Standard Specification for Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel Products 4. GB088-2013-200-CS-SP-002 – Engineering Specification to structural steel work
3.
RESPONSIBILITIES Production Engineer / QC Inspector
4.
PROCEDURE Preparation for Galvanizing Materials: a. The Production Engineer decides on the article suspension method either tying or placing them in suitable fixture taking into consideration the following points, Articles shape, size, weight & Identification of member number. Position of venting & drainage holes ( if required ) Availability of tying points b. Vent holes & drainage holes (As per ASTM A385, FIG-6.7) if required, shall be drilled as per Job material requirements. Dia 8 mm to 15 mm as required, if required depending upon shape and size. c. Pre-weighing - Articles are weighed on the calibrated balance & weight of items recorded in logbook. d. All articles to be galvanized shall be handled in such a manner as to avoid any mechanical damage and to minimize distortion due to mechanical force. 1) Blasting & Cleaning the surface of steel articles : a. Articles are blasted with Automatic shot blasting method by using steel shots S-170 grade or other grades. Used steel shots / scales are collected in drums & refilled with new shots & used shots are disposed off to authorized dump yard. b. Articles are blasted to ensure that the surface is entirely free of rust and other visible contaminants. The shift foreman determines the no. of rounds required according to surface condition of articles. c. Blasted articles are inspected visually by the Quality control engineer & items shall be shot blasted to a surface cleanliness of Near –White Blast Metal.( SA 2-1/2 grade blasting surface finish (as per
SSPC,SP10)
d. Any incomplete blasted areas are assessed by QC Inspector to determine whether the contaminant can be removed during the pickling process. e. After blasting each article is tilted & shot particles shall be removed from inside portion of each article by shaking each other.
G. K. WIRE INDUSTRIES LLC P.O.Box - 32820 , RAS AL KHAIMAH , United Arab Emirates RAK - Tel.(9717) 2447970 , FAX.( 9717) 2447515 Head Office, Dubai - Tel.(9714) 8872904 , Fax.(9714) 8816250 E-mail :
[email protected]
f.
2.2 to 2.5mm dia. Black annealed wire pieces are used for tying the articles to the frames. The batch articles are spaced along the frame to ensure no contact with each other. g. The frames are attached to cranes & the wired articles are checked for uniform distribution, venting & drainage. 2) Degreasing Articles are dipped in batches in degreasing tank to remove organic contaminants including dirt, water based paint markings, grease and oil. Degreased objects are visual inspected for removal of impurities on the surface. Articles are lifted and tilted to drain all solution from articles. 3) Water Rinse After cleaning articles are rinsed in water by immersing in Water bath. Again articles are lifted and tilted to drain the water. 4) Pickling ( HCL Acid cleaning process ) a. After degreasing, articles are immersed for approx. 2 to 5 minutes in the pickling solution depending upon the size, type, shape and surface condition of the articles. Pickling is performed to remove mill scales and /or surface rust. b. Pickling solution comprising of commercial grade HCL acid (33%) diluted with water to approximately 15% strength during fresh start of acid bath. c. In regular use the shift foreman / QC Inspector visually inspects the articles for cleanliness after pickling process. d. On rejection articles are repeatedly pickled until the above conditions are achieved. e. In regular use depending upon the quality of pickled galvanized materials the fresh acid + water in 2: 1 ratio respectively is added directly into the acid bath until the required pH is achieved. Quality of Pickled galvanized materials > Heavy coating thickness, Zinc flaking or peeling / chipping of zinc > Replenished the acid bath. f. HCL Concentration > Min.17 - 18% & Required pH Value > Min. 7 g. If the acid is found weaker for process then it is collected in containers which are neutralized to 7pH by adding caustic soda & samples are sent to an independent laboratory for analysis. Test analysis certificate to be obtained & submitted to local Authority for approval. After approval from Local Authority, this neutralized acid is disposed off to approve dump yard location. h. Following Criteria is used for changing the complete acid from bath : Weaker Acid strength > Blisters on galvanized surface, Black surface, Black spots, pH value 2-3, Iron content (Fe) 150gms/lit. max., HCL concentration % > Complete replacement of old acid from bath. i. Acid strength shall be checked every 15 days interval at in-house laboratory & samples are analyzed for Acid concentration & Iron content. Acid pH shall be checked everyday with pH paper at the beginning of the shift. j. The finished materials are bundled & packed as per job requirements & dispatch note is issued. If direct delivery is arranged for finished materials then loading requisition note is issued against the loaded materials.
G. K. WIRE INDUSTRIES LLC P.O.Box - 32820 , RAS AL KHAIMAH , United Arab Emirates RAK - Tel.(9717) 2447970 , FAX.( 9717) 2447515 Head Office, Dubai - Tel.(9714) 8872904 , Fax.(9714) 8816250 E-mail :
[email protected]
5) Water Rinsing Process : a. Pickled articles are dipped into the rinsing bath completely & suspended over the bath until water no longer pours off. b. Samples from rinsing water bath checked with pH paper every 7 days for determining the pH value, results are recorded. Fresh water shall be added when water becomes too acidic (pH
