annexure 2 to corrigendum 4 to flare system · pdf filethe galvanising kettle, ... centrifugal...

ANNEXURE 2 TO CORRIGENDUM 4 TO FLARE SYSTEM TCE.6079A-C-266-301

TATA CONSULTING ENGINEERS SECTION: WRITEUP
GALVANISING OF STRUCTURAL STEEL SHEET OF 3
1
1. SCOPE
This specification covers the general requirement of Hot dipped galvanising,
Electroplated, Sheardized and Sprayed Zinc coating of the structural
steelwork. It covers the supply of all materials, labour, tools, plant,
equipment, necessary to galvanise the structures in accordance with
specifications.
2. GALVANISING PLANT
2.1 The BIDDER shall indicate in his bid the galvanising plant where galvanising work will be carried out. Prior approval shall be obtained from OWNER/
ENGINEER if galvanising proposed to be carried out outside Contractors
plant.
3. WORKMANSHIP
3.1 After all shop work is complete, all structural material shall be punched with the erection mark to be hot-dip galvanised. Before galvanising, the steel shall
be thoroughly cleaned of any paint, grease, rust, scale, acid or alkali or such
other foreign matters as are likely to interfere with the galvanising process or
with the quality and durability of the zinc coating as specified in clause 4 of
IS : 2629. Pickling followed by Rinsing shall be carefully and properly done
as specified in IS: 2629.
3.2 Zinc conforming to any grade specified in IS : 209 shall be used for galvanising. Mass of zinc coating under specified otherwise shall be at least
0.610 kg/sq. m. of total surface area for normal or rural atmosphere. In case of
industrial atmosphere, minimum mass of coating shall be increased as agreed
to between the Galvanizer and Purchaser. Stub members and members for
grillage type footing shall have heavier zinc coating of not less than 0.80
kg/sq. m. Where required by Purchaser, Post Treatment such as Chromating or
Phosphating may be applied to reduce risk of wet storage staining or to assist
subsequent painting, respectively.
3.3 The galvanised surface shall consist of continuous & uniformly thick coating of zinc, firmly adhering to the surface of steel. The finished surface be cleaned
& smooth & be free from imperfections as flux, ash and bare patches, black
spots, pimples, lumpinch, runs, mist stains, bulky white deposits and blisters.
The presence of any of these defects noticed on visual or microscopic
inspection shall render the material liable for rejection. Sampling and nos. of
test for coating characteristics shall be as specified in IS : 4759. Mass of zinc
coating may be determined in accordance with IS : 6745.
3.4 There shall be no flanking or loosening when struck squarely with a chisel faced hammer. The galvanised steel member shall withstand minimum four no
of one minute successive dips in copper sulphate solution kept at temp. of 18

2
2 0C as per IS : 2633 unless specified otherwise. If at anytime during the test,
there is any doubt as to presence of exposed base metal as determined by
visual inspection, one or more of supplementary tests as specified in Cl.6.1 or
6.2 of IS: 2633 should be performed. Where practicable, uniformity of
galvanised coating shall be determined by Preece test as described in IS: 2633
Use of Preece test should be agreed to between Purchaser and Galvanizer. For
Hot dipped galvanised steel members, coating shall withstand the Pirotted
hammer and Knife tests as prescribed in IS: 2633 for testing adhesion of zinc
coating on fabricated steel and hardware respectively.
3.5 All galvanised members shall be treated with Sodium Dichromate solution or an approved equivalent after galvanising, so as to prevent white storage stains.
3.6 Galvanising of each member shall be carried out in one complete immersion. Double dipping shall not be permitted. When the steel section is removed from
the galvanising kettle, excess spelter shall be removed only by bumping.
3.7 Whenever galvanised bolts, nuts, locknuts, washers, accessories etc. are specified, these shall be hot-dip galvanised. Spring washers shall be electro-
galvanised. Excess spelter from bolts, nuts, etc. shall be removed by
centrifugal spinning. Rechasing of bolt threads after galvanising shall not be
permitted. Nuts however may be tapped, but not to cause appreciable rocking
of the nuts on the bolts. Readily available GI nuts, bolts and washers
conforming to galvanising requirements may also be used.
3.8 Defects in certain members indicating presence of impurities in the galvanising bath in quantities larger than that permitted by the specifications
or lack of quality control in any manner in the galvanising plant, shall render
the entire production in the relevant shift liable to rejection.
3.9 Sufficient care should be exercised while storing, packing and handling. Contractor shall ensure that galvanising is not damaged in transit. While
storing and transporting, adequate ventilation should be provided as otherwise
White rust or Wet storage stain may result with humidity and atmospheric
gases. In the event of occurrence of any damage, contractor shall at its own
cost adopt scrapping & regalvanizing the member to satisfy the specific
requirements. In many cases, it will be advisable to give a Post-treatment like
Chromatting to minimise chances for formation of white rust.
4. METHOD OF MEASUREMENT
4.1 Galvanising work shall not be measured separately if galvanising is already included in the scope of item of work of fabrication/erection of steel.
4.2 In case the galvanising is to be carried out on already fabricated steel work, a separate rate for galvanising shall be quoted as called for in the Schedule of
Quantity. The weight of the actual completed structures including weight of

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bolts, nuts and washers shall be calculated from the approved drawings for
different items of work and NO ALLOWANCE in weight will be made for
weight of zinc added due to galvanising.

SPEC. NO. TCE.6079A-C-266-301
TATA CONSULTING ENGINEERS LIMITED SECTION: Performance Guarantee
FLARE SYSTEM SHEET 1 OF 1
SEAL &
SIGNATURE OF THE BIDDER
FILE NAME: 6079AC266301_PG.DOC TCE FORM NO. 329 R5
ISSUE R0
PERFORMANCE GUARANTEE
S.No
Utilities Units Continuous Requirement
Intermittent Requirement
1. Water Kg/hr
2. Medium Pressure Steam Kg/hr
3. Fuel Gas Kg/hr
4. Power kWH
5. Noise Level at Stack Base for full load of steam only (

TATA CONSULTING ENGINEERS LIMITED SECTION: TITLE
TCE.6079A.590-LS-1001 PIPING MATERIAL SPECIFICATION
SHEET i OF iii OF 4
REV. NO. P0 P1 R0 R1
ISSUE
INITIALS SIGN. INITIALS SIGN. INITIALS SIGN. INITIALS SIGN.
PPD. BY VRP -sd VRP
CHD. BY DSJ -sd DSJ
APD. BY RRP -sd RRP
DATE 07.07.2010 08.11.10
FORM NO. 020R3
PIPING MATERIAL SPECIFICATION
PMC SERVICES FOR THE UTILITIES & OFFSITES OF
NHT/CCR
FILE NAME: TCE-6079A-590-LS-1001P1

TATA CONSULTING ENGINEERS LIMITED SECTION: CONTENT
TCE.6079A.590-LS-1001 PIPING MATERIAL SPECIFICATION SHEET ii OF iii OF 4
ISSUE P1
FORM NO. 120 R1
CONTENTS
SL.NO PIPE CLASS REV SH.NO.
1 LEGEND P0 1
2 PMS FOR CA2 GRADE P0 2
3 BRANCH CONN. CHART FOR CA2 GRADE P0 4
4 PMS FOR CB2 GRADE P0 5
5 BRANCH CONN. CHART FOR CB2 GRADE P0 7
6 PMS FOR CD2 GRADE P1 8
7 BRANCH CONN. CHART FOR CD2 GRADE P1 10
8 PMS FOR CF2 GRADE P1 11
9 BRANCH CONN. CHART FOR CF2 GRADE P1 14
10 PMS FOR CC2 GRADE P0 16
11 BRANCH CONN. CHART FOR CC2 GRADE P0 18
12 PMS FOR CC3 GRADE P1 19
13 BRANCH CONN. CHART FOR CC3 GRADE P1 21
14 PMS FOR SB2 GRADE P0 22

annexure 2 to corrigendum 4 to flare system · pdf filethe galvanising kettle, ... centrifugal...

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