TENDER FOR ANNUAL RATE CONTRACT FOR HOT & COLD INSULATION AND REFRACTORY LINING & COATING WRAPPING OF UNDER-GROUND PIPING. Documents consist of the following:
-1. Letter inviting tender. 2. Tender form.
3. Definition of terms.
4. Scope of work with detailed material specifications for hot & cold insulation, PUF (Poly-Urethane Foam) by In-Situ method and spray insulation on drive turbine casing of compressor as per Annexure-I
5. Scope of work with detailed material specifications for refractory lining as per Annexure - I
6. Scope of work with detailed material specifications for coating & wrapping of piping as per Annexure - I
7. Schedule of rates as per Annexure - II 8. General terms & conditions.
NOTE:
1. HOT INSULATION: Hot Insulation will be done with LRB (Lightly Resin Bond) Rock Fibres Mattress with Wire Mesh Machine stitched on one side with Density of 120 Kg/M3. Hot Insulation of Boiler, Equipment, Vessel, Tank, Chimney, ESP, Piping & Pipe Fittings; Duct & Other Industrial applications will be done with only LRB Mattresses/Pipe Sections. LRB should be confirmed to IS - 8183 and IS - 9842.
2. Mineral wool will not be used for Hot Insulation jobs. Mineral wool shall be used in Cold Box only with a density of 200 Kg/m3.
3. Cold Insulation will be done with Thermocole and material shall be Self Extinguishing performed expanded polystyrene with closed cell structure with density of 18 Kg/ M3 as per IS-4671.
4. The PUF material should be confirming to BS 476, Part-7, 1971 Class "I" & BS 4735-1971 Class "O" extent of burning - nil and self extinguishing type as per ASTM-D-1692-68 with water vapour permeability 5.84 x 10 Gm/M2.(4 per inch) of density 32+2 Kg/M3.
5. The Contractor shall use steel tubular scaffolding alongwith couplers while carrying out foam spray insulation and Hot & Cold Insulation work on tower. Contractor has to confirm in his bid that they will use the steel scaffolding as mentioned above.
6. All rates should be quoted in words & figures strictly in schedule of rates supplied by NFL alongwith tender documents.
DEFINITIONS OF TERMS
In the contract documents herein defined where the context so admits, the following words and expression will have the meanings assigned to them respectively:
1. "The Owner" means the National Fertilizers Ltd., incorporated in India. having its registered office at SCOPE COMPLEX, Core No - 3, 7, Institutional Area, Lodhi Road, New Delhi-110003.
2. The "Engineer-in-Charge" shall mean the person designated as such by NFL and shall include those who are expressly authorized by him to act for and on his behalf for operation of this contract.
3. The "Work" shall mean the works to be executed in accordance with the contract or part thereof as the case may be and shall include all extra, additional, altered or substituted works as required for purpose of the contract.
4. "Construction Equipment” means all appliances and equipment of whatsoever nature for the use in or for the execution, completion operation or maintenance of the work unless intended to form part of permanent work.
5. "Site" means the areas in which the work are to be performed by the Contractor and shall include a part or portion of the Site on which the permanent work is proposed to be constructed.
6. The "Tender Documents" shall consist of Short Tender Notice, General Instructions to the tender, general conditions of contract, special conditions of contract, specifications, drawings, time schedule tender form, proforma or agreement form, schedule of rates, and addendum/addenda to tender documents.
7. "The Contractor” means may person or persons or firm or company whose Tender has been accepted by NFL with the concurrence of the owner, and the legal personal representatives, successors and permitted assigns of such person, persons firm or company.
8. The "Contract” shall mean the agreement between NFL and the contractor for the execution of the works including therein all contract documents.
9. The “ specifications” shall mean the various Technical specifications attached and referred to in the tender documents. It shall also include the latest addition of relevant Indian Standard specifications published before entering into contract.
10. "The Drawings” shall include maps, plans and tracings OR prints thereof with any modifications approved, in writing by the Engineer-in-charge and such other drawings as may, from time to time, be furnished or approved in writing by the Engineer-in-charge. 11. The "Contract Documents" shall consist of agreement, tender documents as defined in
clause 6, 7 & 8 above, acceptance of tender and further amendments.
12. The "Alteration Order" means an order given in writing by the Engineer-in-charge to affect additions to or deletion from and alterations in the works.
13. The "Completion Certificate" shall mean the certificate to be issued by the Engineer-in-charge when the works have been completed to his satisfaction.
14. The "Final Certificate” in relation to a work means the certificate issued by the owner after the period of liability is over.
15. The "Period of Liability” in relation to work means the specified period from the date of issue of completion certificate upto the date of issue of final certificate during which the contractor stand responsible for rectifying all defects that may appear in the works.
16. 'GTC' means General Terms & Conditions of contract.
Annexure - I HOT & COLD INSULATION
SCOPE OF WORK
It includes but not limited to the following:
1.1 Supply of complete raw material required for Maintenance of Hot & Cold Insulation including Transportation, Loading, unloading etc. Strictly in accordance with detailed specifications of materials and Job specification.
1.2 Removal of Hot & Cold Insulation strictly as per instructions of Engineer-in-charge. 1.3 Application of Hot & Cold Insulation including transportation of material to site,
handling etc. in accordance with Specifications, Standards & instruction of Engineer-in-charge
1.4(a) Removal of Mineral wool from cold box and mineral wool after removal from cold box shall have to be filled in jute bags and stored at a place as indicated by Engineer-in-charge, so that wastage is minimum.
(b) Filling of mineral wool in cold box. The mineral wool taken out shall be re-used to maximum extent possible.
DETAILED MATERIALS AND JOB SPECIFICATIONS for HOT INSULATION 2.1 INSULATION THICKNESS
The Insulation thickness for Piping, Vessels, Equipment etc. shall be calculated based on normal operating temperatures and shall be got approved from Engineer-in-Charge before starting of the work. The thickness of insulation for personnel protection shall be determined from Table-2
The thickness of Insulation given in Table-1 and Table-2 for Heat conservation and personnel protection is based on Insulating material specified in Para 2.2.0
2.2.0 INSULATION MATERIALS
2.2.1 All materials used for Insulation fixing and protection shall be new and shall confirm to the specifications details given below. However, if any old material removed is in good condition the same can be used after getting approval of Engineer-in-charge. No payment will be made towards the cost of this old material. All insulating materials whether dry or wet shall be non-corrosive to the surface insulated.
2.2.2. The Insulating Material shall be mineral wool or equivalent/LRB (Lightly Resin Bond) as per ASTM-C 592-70 Type 2/IS 3677- 1973 Type 2/IS-8183 and IS-9842.
2.2.3 The insulation materials shall consist of mineral wool fibbers which shall be taken to include rock and slag wool only. The fibre shall be ductile, tough, non hygroscopic and extremely fine with diameters between 4-7 microns. They shall be formed under normal working conditions and there should be no setting over an extended period of use.
2.2.4 DENSITY:
The applied density of the mineral wool shall be 120 Kg/M3 for temperatures below 450o C and 200 Kg/M3 for temperatures between 450o C to 600o C. The apparent density under specified loading shall be determined as per IS: 3144.
2.2.5 The thermal conductivity of insulation material for densities of 120 Kg/ M3 and 200 Kg/ M3 shall be as given in IS: 3677-1973 and determined as per IS: 3346 OR other National Standards. The thermal conductivity should be given at mean test temperature ranging from 50o C to 400o C in steps of 50/100o C at different applied densities.
2.2.6 The material should be suitable for continuous use upto a temperature of 600o C without degradation, settlement or other detrimental change in its form OR composition.
2.2.7 The material should be relatively free from shot content (unfinished material) which should not exceed 10% by weight when sieved through IS sieve (Spec. IS: 460-1962) of 500 microns. No shot shall be larger than 5mm in size (As per IS: 3677-1966)
2.2.8 Sulphur content should not exceed O.6% (IS: 3677-1966)
2.2.9 Water absorption should not exceed 2% by weight (IS: 3677-1966) 2.2.10 Chloride content shall be limited to 35 ppm.
2.2.11 The material shall be chemically inert, rot and vermin proof and shall not cause corrosion when applied to steel surfaces under conditions of limiting operating temperatures. 2.2.12 The above properties should be tested as per IS: 3144-1965 Method of Test for Mineral
Wool/LRB Thermal Visulating properties.
2.2.13 The mineral wool fibres shall be made into mattresses preferably machine stitched at the factory itself and should retain their form under ordinary handling conditions. The metal facing used for backing the blankets should consists of the specified galvanized iron wire netting. For use on piping upto 12” dia the blanket should be backed on only one side with wire netting, where as for piping above 12" dia and for vessels and equipment the blanket should be backed on both sides with wire netting. For double and multi layer insulation the second and the subsequent layer blankets should have only one side wire netting.
2.3.0 ANCILLARY MATERIALS:
2.3.1 WIRE NETTING, LACING AND STITCHING WIRE:
Wire netting shall be galvanized, 20mm chicken mesh and not less then 20 SWG as metal facing for the mineral wool fibres except in case of machine stitched mineral wool mattresses where 3/4 x 21 SWG GI wire netting shall be acceptable. Lacing & stitching wire shall be 20/10 SWG GL wire respectively.
2.3.2 BANDS:
Bands for securing insulation material on Large Vessel and Equipments shall be Mild Steel painted/GI of 3/4-inch width X 24 SWG for insulation material.
2.3.3 SCREWS:
Self-tapping screws used with aluminium sheeting shall be 1/2” No.8 cadmium plated flat or pan head, tin screws of best quality (GKW or Equivalent).
2.3.4 FINISHED MATERIALS:
Commercial quality aluminium jacketing shall be used on overall piping vessel and equipment of following thickness:
Sno. Application Aluminium Gauge
1. For Pipes having dia upto 500mm over Insulation 24 G 2 For Pipes, Vessels & Equipment having dia more
than 500mm over insulation
22 G 3. For Valves, Flanges and other areas where
Mechanical damage is likely to occur such as Pipes exposed to foot traffic under dykes etc.
20 G
The Metal Sheets should be bent true to shape grooved and properly screwed.
To ensure perfect water proofing, all the above sheet metal joints should be packed with sealing materials which may either be in the form of a bituminous sealing compound or fibre based bituminous felt strips to IS: 1322-1970 Type - 2, Gr-I
2.4.0 SPACER RINGS:
In case any spacer rings is found damaged, the contractor shall make arrangement to replace the same.
2.5.0 CLIPS:
Removable covers of all flanges and valves where required shall be secured in place by means of bands or quick release clips.
2.6.0 SEALANTS AND MASTICS
2.6.1 Non-conductive hard setting content to ASTM-C-194-70 or other equivalent standard. 2.6.2 Bitumenized roofing felt to IS: 1322-1970 Type-2, Gr-I
2.6.3 Mastic Sealer to be given by Contractor to withstand a temperature of 600o C (Min) 2.6.4 Aluminium foil 0.1 mm thick
2.6.5 Weather Proofing Mastic shall be bitumenized asbestos insulkote or equivalent. 2.7.0 REMOVAL AND APPLICATION:
The insulation areas to be removed will be shown by the Engineer-in-charge when required. The insulation has to be refixed on the same portions, similar to the old patterns and thickness with the instructions of Engineer-in-charge.
2.7.1 SINGLE LAYER INSULATION:
Blankets shall be dry installed on to the Vessel and shall be secured with metallic bands. 2.7.2 MULTI-LAYER INSULATION:
When insulation thickness exceeds 75mm. the insulation shall be applied in multi layers with all joints staggered. Each layer shall be separately secured with metallic bands.
2.7.3 Filling all cracks and voids in main insulation shall be completely packed with loose mineral wool.
TABLE-I
(RECOMMENDED THICKNESS IN MM FOR MINERAL WOOL INSULATION)
Pipe dia
Temperature in Degree Celsius Upto 90 91 to 150 151 to 250 251 to 350 351 to 450 451 to 550 551 to 650 651 to 750 751 to 850
I II III IV V VI VII VIII IX
1&1/2 (40 mm) 25 25 25 40 50 65 75 100 125 2”-3” (50-80 mm) 25 40 40 50 60 75 100 125 150 4”-6” (100-150 mm) 25 40 50 75 75 100 115 130 150 8”-10” (200-250 mm) 40 40 50 75 100 115 130 150 175 12” & above (300 mm &above) 40 40 65 100 100 115 130 150 175 TABLE - II
PERSONNEL PROTECTION INSULATION THICKNESS IN MM FOR MINERAL WOOL
OPERATIONG TEMPERATURE IN DEGREE CELCIOUS
Pipe size (in inch)
Operating Temperature in Degree Celsius Upto 100 101 to 200 201 to 300 301 to 400 401 to 499 500 to 600 6 & under 25 25 25 40 40 50 8-12 25 25 40 40 50 63 14 & above 40 40 40 50 50 63 Vessels & Equipments 40 40 40 50 63 63
COLD INSULATION
3.1.0 The Insulation thickness for piping equipment etc. shall be calculated based on normal operating temperature and shall be got approved by the Engineer-in-charge. The thickness of insulation given in Table-IA & IIA are based on insulation material self extinguishing performed expanded polystyrene with closed cell structure with density of 18 Kg/M3 as per IS-4671.
3.2.0. INSULATION MATERIALS:
All materials used for insulation, fixing, sealing and protection shall be New and shall confirm to details given below. However, if the material removed is in good conditions, it can be used again, after approval of the Engineer-in-Charge. The insulating material shall be self-extinguishing, performed expanded polystyrene conforming to IS: 4671 type SE.
3.2.1 The insulating material shall be polystyrene foam prepared from styrene Homo polymer or Compolymer containing an expanding agent. The finished foam in the form of slabs or half sections shall be of uniform closed cell structure free from unreacted materials, shrinkage and distortion.
3.2.2 i) Density: The applied density of Expanded Polystyrene shall be 18 Kg/M3. ii) Thermal Conductivity: Thermal Conductivity of insulation material for density
18 Kg/M3 shall be as given below:
Mean Temperature (Degree Celsius) Thermal Conductivity (Kcal/MK)
0 0.025
10 0.027
20 0.028
iii) Water Vapour presence shall not be more than 0.4gm/M2, 24mm Hg as per IS: 661
iv) Chloride content - 35 ppm
3.3 WIRE NETTING, LACING & BINDING WIRE:
i) Wire Netting shall be galvanized 24 SWG x 20mm to secure insulation blocks and binding lacing wire shall be 16 SWG galvanized wire.
ii) BANDS:
A Fibrous material like bonded mineral wool shall be used at the contraction joints.
iii) BITUMEN:
Bitumen emulsion to be used as adhesive for sections/slabs and as vapour barrier with glass fabric or R.P. tissue shall be 85/40 or 85/25 type to IS: 702.
iv) Mastic shall be emulsified asphalt product containing asbestos fibres and suitable for application with a trowel. Reinforcing membrance used with mastic shall be 20 x 20 mesh glass cloth of 5 mils. or R.P. tissue with an asphaltic primer applied to promote adhesion to the mastic compound.
3.4.0 REMOVAL AND APPLICATION:
The insulation to be removed from piping, vessel, equipment etc. will be shown by the Engineer-in-charge. The insulation shall have to be applied on the portion in similar to the old pattern and thickness with the instructions of Engineer-in-charge.
3.4.1 SURFACE PREPARATION:
The surface to be insulated shall be cleaned and dried. All surface irregularities shall be filled up with suitable approved sealer. One coat of anti-corrosive primer (Red oxide Zinc chromate) shall be applied over the carbon steel surface to be insulated and allowed to dry before application,
3.4.2 INSULATION THCIKNESS AND LIMITS:
Insulation thickness shall be in accordance with the attached Tables-I & II. The thickness limits of the applied insulation shall be -5% to 20%. Insulation thickness excludes the additional thickness resulting from outside finish and Vapour Barrier. Multi-layer construction can be used for an insulation thickness 50 mm and above or where operating temperature is -40o C and below. There shall be no through joints. A guide line for multi layer insulation is given in the Table IIIA.
3.4.3 VAPOUR BARRIER:
A vapour barrier meant to prevent moisture penetration into the insulation, shall be applied over the insulation as per the following steps:
a) One coat of bitumen emulsion (2.5 mm thick when dry) shall be applied on the polystyrene half sections/slabs.
b) Glass fabric or R.P. tissue shall be applied with minimum overlap of 50 mm over the first coat of bitumen emulsion when the later not fully dried.
c) An other coat of bitumen emulsion (1.5mm thick when dried) shall be applied over the glass fabric.
3.4.4. VAPOUR BARRIER & WEATHER PROTECTION: a. Providing Hot Blown Bitumen 85/25 @ 1.5 Kg/M2 b. Wrapping Fibre Glass or R.P. Tissues.
c. Providing Hot Blown Bitumen 85/25 - 1.5 Kg/M2 d. Providing one layer G.I. wire netting 20mm X 24 G e. Providing one layer of Bitumen Emulsion of 2.5mm thick. f. Wrapping or R.P. Tissue 50 mm overlap.
g. Providing 2nd layer of bitumen emulsion of 1.5 mm thick. 3.4.5 FIELD WELDING:
Field welding of clips or other insulation supports on any vessel or piping shall not be permitted.
3.4.6 FILLING:
All the cracks and voids in the main insulation shall be filled up with polystyrene dust mixed with adhesive and sealed with adhesive.
TABLE-1A
Cold Insulation of Vessels and Equipment Table of Thickness for Expanded Self Extinguishing
polystyrene as per IS - 661 - 1975, DIN - 53428 (OPERATING TEMPRATURE IN DEGREE CELSIUS)
Vessel dia (in Meter) +10 to +5 +4 to -6 -7 to -18 -19 to -32 -33 to -45 -46 to 60 -61 to -75 0 to 1 48 70 92 115 140 164 191 1 to 1.5 50 75 95 115 140 165 190 TABLE - II-A
COLD INSULATION OF PIPING
Table of Thickness for Expanded Self Extinguishing Polystyrene (OPERATING TEMPRATURE IN DEGREE CELSIUS)
Nominal Pipe dia (in inch) +10 to +5 +4 to -6 -7 to -18 -19 to -32 -33 to -45 -46 to -60 -61 to -75 3/4 & under 30 40 45 55 65 75 85 1 30 40 50 60 70 80 90 1&1/2 35 45 55 65 75 85 100 2 35 45 55 70 80 90 105 3 40 50 60 75 85 100 110 4 40 50 65 80 90 105 115 6 40 55 70 85 100 110 125 8 40 60 75 90 105 120 130 10 45 60 80 95 110 125 140 12 45 65 80 100 110 125 145 14 45 70 85 100 115 130 150 16 45 70 85 105 115 130 150 18 45 75 90 110 120 135 155 20 50 75 95 110 120 135 155 24 & above 50 75 95 110 120 140 160
Note: Thickness do not include finish thickness.
TABLE - III-A THICKNESS DETAILS
Number of layers required for Insulation(Thickness Exceeding 50 mm)
Total thickness 65 75 100 101 to 150 160 to 200 201 to 300 301 to 400 1st Layer 25 25 50 50 50 75 75 2nd Layer 40 50 50 50 50 75 75 3rd Layer 50 50 75 75 4th Layer 50 75 75 5th Layer 75 75
4.0.0 TEST CERTIFICATE:
The Contractor have to submit test certificate for the material used from recognized Laboratories, whenever these are asked by Engineer-in-charge. The test certificate should cover all the properties given in relevant IS specifications or applicable International Material Standard.
5.0.0 MEASURE OF WORK:
Basis of measurement for Hot and Cold Insulation shall be the same. Physical measurement will be taken by the representative of Engineer-in-charge in presence of the contractor or his representative and payment will be made on actual measurements. However, measurements will be in Metric System corrected to the nearest centimeter. Measurement shall be taken over finished insulated surfaces in all cases as per IS-7413, 1981.
5.1.0 COLUMNS, VESSELS EXCHANGERS AND EQUIPMENTS:
Measurement shall be taken/considered over finished insulation surface in all cases. No deductions shall be made for any area required to be left uninsulated, the area of which is equivalent to circle of 600 mm in diameter or less. In case of Horton Sphere Insulation, 25% of the quoted rates shall be paid extra.
5.1.1 All insulated nozzles/projections/manholes shall be measured as given below:
a) As piping insulation, if the area of such nozzle/projection is equivalent to a circle of 600 mm in diameter or less. The area covered by such nozzle of projection shall not be deducted from the overall area of tank/column/vessel/ exchanger/equipment insulation measurements.
b) If any nozzle/nozzle/projection/manhole insulated is equivalent to a circle of over 600 mm in diameter, the area of such nozzle/projection/manhole to be considered for measurements shall be taken as twice the actual insulated area and paid for as vessel insulation. The area of tank/column/vessel/exchanger/ equipment, covered by such nozzle/projection/manhole shall be excluded from measurements.
5.1.2 Dished ends of vessels shall be considered as twice the projected circular area of the dished end for purposes of measurement.
5.2.0 PIPING
5.2.1 All measurements for piping shall be taken over the finished insulated surface in meters, corrected to nearest centimeter along the centre line of piping, through all fittings, insulated or otherwise, such as valves, flanges, elbows, bends, tees and reducers.
5.2.2 Insulation of valves, flanges or other fittings shall be measured through such valves, flanges or other fittings as per 5.2.1 above and in addition extra measurements shall be allowed as follows:
a) For each insulated valve and venturi including flanges and body, 1.50 linear meters of piping of the connected line size upto 300 mm line size and 2.00 linear meters for larger sizes.
b) For each pair of insulated flanges including orifice plate and flanges, 0.80 linear meters of piping of the connected line size.
c) All insulated bends, elbows, and tees, twice the equal length of such fittings of concerned connected line sizes as measured along their centre lines. In case of insulated welded tees, twice the diameter over insulation of each of the two pipes forming the tee is to be added to the overall length.
d) Any other special fittings not covered under the above shall be specified and measured separately on number basis.
5.2.3 Insulated reducers connecting two different diameters of pipes shall be reckoned as equivalent piping of larger diameter for purposes of measurement of insulation.
5.2.4 Steam traced and non-steam traced pipelines shall be normally specified and measured separately. Steam-traced pipelines with single or multiple tracers shall also be normally specified and measured separately according to the number of traces.
5.2.5 Anti-corrosive painting or wrapping with aluminium foil over stainless steel/alloy steel piping and equivalent prior to application of insulation, shall be measured separately. 5.2.6 Insulation of Instruments shall be measured separately and length covered by such
instruments which are not axial with the pipe line shall not be considered in the measurement of the connected piping insulation.
5.3.0 Insulation of steam tracing line is to be carried out in following steps:
-i) Steam traced line should be tied to the pipe with the help of SS 20 gauge lacing wire.
ii) Providing Aluminium foil over the steam traced line.
iii) Providing lagging over Aluminium foil after providing wire netting on both side of wool blanket.
iv) Providing Aluminium sheeting over the Lagging. REFRACTORY LINING 6.0.0 SCOPE OF WORK
6.1.0 Boiler, Steam Super Heater, Start up Heater, Heat Exchangers, Incinerator and Package Boiler.
6.1.1 Removal of damaged insulation bricks by chipping & cutting etc. 6.1.2 Removal of damaged Refractory concrete by chipping if necessary.
6.1.3 Surface cleaning by brushing and preparing the surface for brick lining/mortar casting. 6.1.4 Dressing of Refractory bricks to the required size by chipping, cutting etc.
6.1.5 Preparing proper fixtures, shutterings for holding in position refractory bricks, refractory mortar till setting.
6.1.6 The refractory brick work is to be carried out with 2mm thick mortar joints expansion joints and sealing joints are to be filled with asbestos material as per requirement. 6.1.7 Application of refractory castable and tubular refractory castable.
a) Mixing required quantity of water to the refractory castable.
b) Castable is to be cast, gunned or trowelled into the place after making voids and from.
c) Calcium Silicate insulation: Fixing of Calcium Silicate on steam lines. 6.1.8 Removal of special fixtures and shuttering after curing of Refractory.
6.2.0 MAIN REACTOR AND SECONDARY REACTORS:
6.2.1 Removal of damaged refractory, castable and concrete etc. from main reactors and secondary reactors.
6.2.2 Cleaning and preparation of metal surface for working it fit for refractory.
6.2.3 To dress the bricks to make five joint of less than 1mm Gap and laying the bricks, castable, concrete etc. as per procedure which will be given to contractor before start of work.
6.2.4 Cutting and fixing of tubes or sleeves for pyrometer insert.
6.2.5 Cleaning the site after completion of work as per instruction of Engineer-in-charge. 7.1.0 DETAILS of MATERIAL & JOB SPECIFICATION
7.1.1 All Refractory material will be issued by NFL free of cost.
7.1.2. Frames, moulds and shuttering if required for refractory lining shall have to be fabricated by Contractor and assembly of forms and shuttering should be such, so as to facilitate their removal without damaging the lining.
7.1.3 Mortar and refractory castable prepared by the Contractor has to be used within permitted time limit. If mortar/castable is wasted due to the Contractor fault the same will be charged to the Contractor. Partial set, damaged or broken bricks are not to be used.
7.1.4 Allowable wastage for refractory concrete/mortar/bricks and castable should not be more than 3%
7.1.5 Whenever castable are used, the surface should be painted with bitumastic paint or covered with paper which will burn out during operation, for creating gap for expansion between castable refractory and the surface.
7.1.6 The installation of material in the reactor should be so perfect that I.D. of lining shall be uniform, level and centre should be maintained.
7.1.7 Specific procedure for carrying out each job will be given to the contractor before hand by in-charge. The entire job is to be carried out as per instruction of Engineer-in-charge and Engineer’s instruction will be final for carrying out job. Further contractor has to make all necessary arrangement for inspection of the job by NFL Engineer.
7.1.8 Forms and shuttering shall be non absorptive, rigidly constructed and sufficiently tight to prevent leakage and their surface should be smooth.
7.1.9 The contractor should quote as per Annexure. However NFL reserves the right to get the job done from the contractor against either of the two.
7.1.10 In case the job is got done as per Item No. 06.01 all other conditions will remains the same except that the payment shall be made on mandays basis.
7.1.11 Equipment likely for the Contractor for Refractory Lining as per Item No.'04.01' COATING & WRAPING OF UNDERGROUND PIPES:
8.0.0 PROTECTIVE COATING OF UNDERGROUND STEEL PIPE WORK The external surfaces of underground steel pipes shall be protected as follows:
-8.1.1 The outer surface of piping and fittings shall be thoroughly cleaned of rust, grease, oil, dirty moisture and foreign material and shall be coated with one coat of Coaltar (Shalimar make Jetset Primer) or approved equivalent to have uniform thickness all round the pipes. The primer coating shall be free of bubbles, globules drips and runs. 8.1.2 After the first primer coat has dried and at least 24 hours after the application of Ist Coat,
a 2nd Coat of Synthetic Enamel shall be applied by brush over the Ist Coat.
8.1.3 Before the 2nd coat of Primer is dry, Single layer of fibre glass "RP Tissue" inner wrap shall be applied spirally around the pipe overlapping at least 20 mm and pulled into the Wet 2nd coating to conform closely to the centre of the pipe. It shall be ensured that the 2nd Coaltar coat impregnators the fibre glass Wrapping.
8.1.4 After the 2nd coat is dry, a 3rd coat of Coaltar/Bitumen enamel (Shalimar make Mastic-4 CTB) or approved equal shall be applied without thinning to completely cover the fibre glass mesh
8.1.5 Before the 3rd coat is dry, a layer of coaltar impregnated KRAFT paper outer wrap shall be applied in similar manner as described at 8.1.4 above. The wrapped pipe shall be allowed to dry thoroughly for not less than 48 hours.
8.1.6 The coverage shall not be greater than 1.75 M2 per Litre of Coaltar/Bitumen enamel. The total thickness of the coating shall not be less than 2.5 mm. The thickness of the pipe coating shall be measured either by Elcometer OR by coating thickness gauge.
8.1.7 A length of 150 mm at the ends shall be left un-coated to facilitate Welding. After the welding of the joints and successful hydrostatic testing of the installed pipe work, the coating & Wrapping shall be applied at the welded joints in a similar way as indicated above.
9.0 COLD INSULATION WITH POLYURETHANE FOAM (PUF) BY IN-SITU METHOD
SCOPE of WORK:
9.1 The Contractor will arrange all Tools & Tackles, Foam Spray Machine alongwith auxiliaries, Scaffolding Material and Consumable required for the execution of Work. 9.2 Contractor should be able to mobilize the sufficient manpower during the short Notice. 9.3 The Contractor shall adhere to all safe working practices as per Factories Act during the
execution of job. NFL is Chemical Factory and contractor will educate his workers about the dangers in the Plant and not smoke in "NO SMOKING AREA". Moreover, the job will be executed during Shutdown, proper care has to be taken to avoid any Accident in the busy area.
9.4 Measurement of the Insulation work will be taken on the Finish Surface as per the relevant IS.
9.5 Contractor must ensure his Workers should be provided with a Safety Helmet and Safety Belt while working at Site.
9.6 The Contractor will arrange all the skilled/semi-skilled manpower and supervisor required for execution of work.
9.7 The work may be required to carry out on round the clock basis as per requirement of the job/plant or as directed by Engineer-in-charge.
9.8 Waste material will not be allowed to get scattered in the working area and the area will be cleaned from time to time.
9.10 NFL will not be responsible for any idle labour charges caused on account of stoppage of job during the course of execution for any unavoidable circumstances/reasons.
9.11 The contractor has to submit the following details with offer, otherwise offer shall be rejected:
-9.12 The Party has to submit sequence of application for the execution of job along with all technical details of the material to be used.
9.13 Party should submit their design calculation for thickness of insulation required vis-à-vis thickness indicated in the tender.
9.14 During execution of the job, the party shall submit calculation for PUF thickness for each job based on operating parameters and confirm proper effectiveness of the insulation. In case, insulation quality is not found effective during defect liability period of six months, the same shall be rectified by the contractor without any extra charge.
9.15 In case of any faulty workmanship/material the contractor has to repair/re-insulate the same without any extra cost.
9.16 Job is to be completed within 10 days after issue of safety work permit. 9.17 Prior approval of Engineer-in-charge is required to start the insulation work. 10.0 GENERAL REQUIREMENT:
10.1 The PUF shall be provided on the Vessels/Tower & Piping containing fluids or vapours which is necessary to:
a) Maintain low temperature for process control. b) Avoid surface condensation and fire proofing.
10.2 All application of spray insulation shall be made in accordance with this specifications detailed in the tender document. The contractor shall submit with his proposal the following information:
a) The Test Certificate of material offered as described.
b) The "K" value curve chart alongwith the literature and name of supplier/ service of procurement.
10.3 PROTECTION OF MATERIAL DURING STORAGE:
Insulation materials must be protected against any damage from delivery to finish coating/cladding Polyurethane chemicals shall be stored in a flat surface in a horizontal position. Insulation material shall never be stocked directly on the ground.
10.4 PROTECTION OF PARTIALLY COMPLETED JOBS:
All precautions shall be taken to ensure that each day's work is vapour sealed as weather proofed during erection and before being left over night to prevent seepage of water into the material and getting trapped. The system shall be protected by Tarpaulin, water shed and other protective means.
10.5 HYDROSTATIC TEST:
Insulation shall be applied on Tower after successful completion of hydrostatic test, all welded and mechanical joints shall be left exposed for testing and subsequently insulated after successful completion of hydrostatic test. prior approval of Engineer-in-charge is required to start the insulation work.
10.6 INSULATION MATERIALS:
The material should be conforming to BS-476, Part-7, 1971 Class-I and BS-4735, 1971 Class "O". The party shall furnish the detailed specifications of PUF that will be used such as:
i) Extent of Burning.
ii) Water Vapour Permeability.
iii) Thermal conductivity for new & aged insulation measured at 10o Celsius. iv) The contractor must submit Test Certificate for the same alongwith the offer.
SEQUENCE OF APPLICATION
The Contractor shall carry out the foam spray insulation work as per the following procedure: 1. Removing existing insulation and disposal of the same to the defined area within plant
limit.
2. Cleaning of Surface with wire brushings/chipping etc. manually. 3. Applying an initial coat of PUF based primer.
4. Fixing of PUF spacer blocks of size 100 mm x 100 mm x Thickness of Insulation at 400/300/200 mm center to center as per the requirement of the job along the circumference using suitable adhesive.
5. Providing/fabricating and fixing of 20 G plain aluminium sheeting over the PUF spacer blocks.
6. Sealing all the joints of Aluminium Cladding with suitable putty to avoid leakage of chemical.
7. Pouring PUF into the cavity created between the bore surface of equipment/ piping and Aluminum cladding using spray equipment (Special Foaming Machine)
8. Repeat the operation of aluminium cladding to the next height and carry out the foaming operation once again till the entire tower is completed.
9. Pouring PUF Chemicals through the power holes, drilled as above and sealing the power holes with aluminium patch plates and joints with putty.
