Manufacturing, corrosion protection, supply, delivery, construction of Mild Steel Pipe lines and its accessories

1. SCOPE

Manufacture, supply, delivery at site, lowering, laying, jointing and testing of specified diameter internal diameter (after inlining) Mild Steel (MS) pipeline using specified thick MS plate with specified thick in lining with CM (1:2) prop., and specified thick out coating with CM 1:3 prop., tested to specified pressure, respectively at factory including civil works from specified locations as per the bill of quantities. The pipeline is proposed to be laid under-ground except in few stretches where it may be laid above ground on ring girder supports or RCC pedestals or on the culverts or bridges or as directed by the Engineer-in-Charge.

2. STANDARDS

The following specifications, standards, and codes are part of this specification. All standards, specifications and codes of practice referred herein shall be the latest edition including all applicable official amendments and revisions.

In case of discrepancy between this specification and those referred to herein, this specification shall govern,

IS 2062 Steel for general structural purposes.

IS 808 Dimensions for hot rolled steel beam, column channel and angle sections

IS 814 Covered Electrodes for manual metal arc welding for carbon and carbon manganese steel

BS 5155 Specification for Butterfly valves

AWSS-5.1 Specification for Mild Steel Covered Arc Welding Electrodes

IS 3613 Acceptance tests for wire flux combination for submerged arc welding

AWS : A-5.17 Specification for Bare Mild Steel Electrodes and Fluxes for Submerged arc welding

IS 1367 Technical supply conditions for threaded steel fasteners

IS 2016 Plain Washers

IS 2074 Ready Mixed Paint, air drying, red oxide zinc chrome, Priming

IS 1786 High yield strength deformed Steel bars and wires for concrete reinforcement.

IS 432 (Part-1) Mild Steel & Medium Tensile bars and hard drawn steel wire for concrete reinforcement :Part 1 Mild steel and medium tensile steel bars

IS 432 (Part 2) Mild steel & Medium Tensile steel bars and hard drawn steel wire for concrete reinforcement : Part 2 Hard drawn steel wire

IS 269 33 grade Ordinary Portland cement

IS 8112 Specification for 43 grade Ordinary Portland Cement

IS 8041 Specification for Rapid hardening Portland cement

IS 12269 Specification for 53 grade Ordinary Portland Cement

IS 455 Specification for Portland Slag Cement

IS 383 Specification for coarse and fine aggregate from natural source

IS 12330 Specification for Sulphate Resisting Portland Cement

IS 4353 Submerged Arc Welding of Mild Steel and Low Alloy Steels-Recommendations

IS 456 Code for practice for plain and reinforced concrete

IS 800 Code of practice for general construction in Steel

IS 816 Code of practice for use of Metal Arc Welding for General Construction.

IS 817 Code of practice for Training and Testing of Metal Arc Welders

IS 1182 Recommended practice for Radiographic examination of Fusion Welded Butt Joints in steel plates

IS 2595 Code of practice for Radiographic Testing

IS 3658 Code of Practice for Liquid Penetrant Flaw Detection

IS 5334 Code of practice for Magnetic Particle Flaw Detection of welds

ASTM E 94 Recommended Practice for Radiographic Testing

ASTM E 109 Dry Powder Magnetic Particle Inspection

ASTM E 138 Wet Magnetic Particle Inspection

ASTM E 165 Liquid Penetrant Inspection

IS 3600 Methods of testing of Fusion Welded Joints and Weld metal in steel

IS 4853 Recommended Practice for Radiographic inspection of fusion welded butt joints in Steel Pipes

IS 3589 Specification for seamless or Electrically welded steel pipes for Water, Gas and Sewage

IS 6631 Steel pipes for Hydraulic Purposes

IS 7343 Code of practice for ultrasonic Testing for Ferrous Welded Pipes and Tubular Products

IS 2598 Safety Code for Industrial Radiographic Practice

IS 5822 Code of Practice for laying of electrically welded steel pipes for water supply

IS 1566 Hard drawn steel wire fabric for concrete reinforcement

IS 6419 Welding rods & bare electrodes for glass shielded arc welding of structural steel.

IS 1974 Bare wire electrodes for submerged arc welding

IS 7307 Approval tests for welding procedures

IS 7310 Approval tests for welders working to approved welding procedures

IS 2720 Methods of test for soils

IS 780 Specification for sluice valves for water work purposes. (50 to 300 mm size)

IS 2906 Specification for sluice valves for water work purposes.(350 to 1200 mm size)

IS 1916 Steel cylinder pipe with concrete lining and coating

IS 7322 Specials for steel cylinder reinforced concrete pipes

IS:5504 & IS 3589

Codes for SW pipes

IS 11906 Recommendation for cement mortar lining for cast iron, mild steel and ductile iron pipes and fittings for transportation of water.

3. MATERIALS

Cement - Ordinary Portland cement conforming to IS 269 and Sulphate resisting cement to IS 12330.

Aggregate - The aggregate shall conform to IS 383

Water - The water used in preparation of concrete mix shall conform to the requirements of mixing water specified in IS: 456

Steel for reinforcement shall conform to IS 1786 or IS 432 (Parts 1 and 2)

Welding consumables - such as electrodes, filler rods and wires shall conform to IS 814, IS 3613, IS 6419 and IS 7280

When requested by the Engineer, the contractor shall provide test samples of the materials to be used in the works for testing. The cost of such tests shall be borne by the contractor and shall be included in his bid quoted.

Structural steel materials of required size and thickness such as channels, angles, nut bolts etc. shall be procured at contractor’s cost confirming to IS 2062. All these materials should be procured from the reputed manufacturers. The Contractors shall submit the original test certificates from the manufacturer for the grade of the material and yield strength. One sample from each lot as per IS specifications shall be tested in the approved laboratory at the cost of the Contractors. If the test reports are not satisfactory, the entire lot will be rejected.

The Contractors shall procure structural steel considering the wastage/scrap etc. and bid quoted shall be inclusive of taking into consideration wastage/scrap. The Contractors should note that no claim whatsoever it may be would be considered on account of wastage and/or scrap etc.

A. MANUFACTURE OF MILD STEEL PIPES, SPECIALS AND FITTINGS

1. General

a. All works and material under specification will be rigidly inspected during all phases of manufacture and testing and such inspection shall not relieve the contractor of his responsibility to furnish material and perform work in accordance with this specification. The Contractor shall notify the Engineer-in-Charge, in advance of the production of materials and fabrication thereof in order that the Engineer may arrange for mill and shop inspection.

b. The Engineer may reject any or all pipes fittings that are of the material specified, that are not fabricated in accordance with the outlined procedure, and that do not obtain the prescribed test results, condition of fittings and tolerance set forth in the relevant IS drawings and the specification.

c. The Engineer shall have free access to those parts of all plants that are concerned with the furnishing of materials of the performance of work under this specification.

d. The contractor shall furnish the Engineer reasonable facilities and space without charge for inspection, testing and obtaining of any information he desires in respect of the character of material used and the progress and manner of the work.

e. The contractor shall provide 2 (two) sets of accurate `go' and `no go' ring gauges to measure the diameter of fittings for the use of the Engineer at no extra cost.

2. Tensile test and Bend test on steel plates

2.1. Test certificates from plate manufacturer shall be treated as final. In the absence of such certificates, tests shall be carried out to prove that the material conforms to IS 2062-Grade-A/B

2.2. Testing of welded joints: The welded joints shall be tested in accordance with IS:3589-2001 as stated earlier in this specification.

2.3. The Engineer may select, for testing two fittings from each batch of 100 pipes or less. If either of the two samples fails to meet the requirements of the appropriate test given below, the Engineer may call for such further fittings to be tested as he may require to satisfy himself that the remaining of the fittings in the batch are satisfactory. If further tests indicate that the welds are unsatisfactory, the Engineer shall have the right to reject the batch or if the manufacturer should so desire, each fitting shall be tested and pipes which fail to comply with the requirements of the specification shall be rejected.

2.4. Bend Tests: Strips 40 mm wide, cut circumferentially from fittings or from coupon plates attached to and welded with fittings, with the weld near the middle of the sample, shall without fracture, is not more than three times the thickness of the test piece, the weld being placed at the point of maximum bending. The test pieces shall on examination of the bent specimen , the opening out of a slight defect due to incomplete root penetration or lack of root fusion need not be considered a cause for rejection provided the defect has sound metal at the back and on either side of it. In border line cases, further tests shall be made on specimens from the same weld adjacent to the original test specimen.

2.5. Tensile Test: The specimen shall be taken from the end of the fitting or at any point in the fitting as directed by the Engineer and shall be cut with the weld approximately in the middle of the specimen. The tensile test specimen shall be flattened and the sides shall be machined. The protruding welded portion from both inside and outside shall be removed by machining before the specimen is tested. If a test specimen shows a defective machining or develop flaws not associated with welding, it may be discarded and another specimen tested. The welded joint shall show strength of not less than the minimum tensile strength specified for plate in accordance with IS 2062-Grade-A/B.

2.6. Re-Test: If the results of bend or tensile test of any lot do not conform to the requirements specified, re-tests of two additional specimens from the same lot shall be made each of which shall conform to the required specifications,. In case of failure of both , extensive gauging and repairing shall be taken in a nearby joint as directed by the Engineer and the procedure stated above is to be repeated until the test specimen stands the required test before the lot can be accepted.

2.7. Expenses for re-testing: All charges in connection with the testing or retesting of the welded samples including machining, testing etc. shall be borne by the contractor.

3. Fabrication and Manufacturing of pipes

3.1. General

The Contractor shall get the fabrication work done in a factory. This factory meant for fabrication of pipes, specials etc. shall also be involved with testing etc., machining as well as inlining/outcoating/painting. For completing the work under the present contract within the contract period, the factory shall be equipped with adequate number of various equipment and plant such as :

i) Plate bending and spiral welding machines

ii) Automatic welding machines (suitable for circumferential welding)

iii) Hydraulic Testing devices

iv) Travelling gantry or cranes of required capacity

v) Mobile cranes for loading/unloading of plates, pipes etc. or required capacity

vi) Lathe for machining of the flanges rings, plates etc.

vii) Equipment for sand blasting and applying paint by spray gun.

viii) Equipment for cold pressing of plates up to 25 mm thick to the required curvature

ix) Equipment for welding at site including diesel generating set.

x) Equipment for measuring the thickness of paint by Elcometer or any other measuring devices.

xi) Inlining / Guniting machinery with heavy compressor.

xii) Hydrulic Tesing of Pipes

The factory shall have adequate area, and shall also have stacking yard for the stacking of plates, structural, fabricated pipes etc. and the scrap.

Bidder shall furnish with his bid the details of the factory where the fabrication will be done, it's location and the equipment and other facilities available in the factory for the manufacture of M.S. Pipes and specials required under this contract.

3.2. Mild Steel Pipes and Short Pipes.

3.2.1.MS Pipes shall be manufactured with specified thick steel plates as per Bill of Quantities. The internal diameter of the pipes shall be as specified after inlining with specified thick cement mortar. The steel plates shall conform to IS:2062-1992 - Grade-A/B (Fe410WA).

3.2.2.The manufacture of MS Pipes and short pipes shall be done in conformity with IS:3589-2001.

3.2.3.Manual metal arc welding with covered electrodes shall also be permissible for field welded joints.

3.2.4.Electrodes shall conform to I.S. 814-1991.

3.2.5.The length of M.S. Pipe shall be 5 M or more. For 5 M length of pipe, only one joint is to be allowed i.e. the width of the plate should not be less than 2 ½ M for the manufacturing of the pipe.

3.2.6.The length of M.S. short pipe shall be as required.

3.2.7.The ends of M.S. Pipes, short pipes shall have bevelled ends for welding.

3.2.8.Ovality of the pipes, short pipes shall be removed before inlining is done.

3.2.9.The MS pipes and specials shall conform to IS:3589 and IS:7322 manufactured either by Electric-Resistance Welding (ERW) or Submerged Arc Welding (SAW) process longitudinally or spirally welded and tested to ENGINEER-IN-CHARGE's specific requirements. The manufacturing process shall ensure that the;

i. Base material i.e. MS Plates, MS Sheets, MS Strips shall be of the required quality.

ii. Production equipment is well designed.iii. Quality control is comprehensive.

3.2.10. During welding the weld gap along with the inner and outer welding heads shall have complete automatic control and are kept within close tolerances. The welding devices shall be equipped with the electronic control consisting of automatic welding voltage and automatic welding control systems. The automatic electronic control systems shall ensure the correct welding parameters i.e. amperage and voltage to maintain a uniform quality of weld. The butt joints of the pipe shall be continuously welded first on the inside and after a half-turn of the pipe and also on outside using the submerged or welding process. The pipes can then be cut into desired lengths by using a rotary oxy-acetylene torch. The pipes manufactured shall be supplied with plain beveled edges and beveled angle being 30o (+ 5o, -0o) measured from a line drawn perpendicular to the angle of pipe with a root face of 1.6 + / -0.8mm.

3.2.11. The pipes manufactured with spirally welding process are to be tested to the following requirements in the presence of Engineer or his representative.

i. Continuous monitoring of dia and forming.

ii. Radiographic testing of the pipe welds for 10% of the welded length as per IS:4853 for the sample of pipes.

iii. 100% Ultrasonic Testing for factory and field welded joints.

iv. Visual inspections of all pipes from inside and outside for permissible tolerances as per IS:3589.

v. All the pipes are to be subjected to hydrostatic test pressure of minimum as specified in Bill of Quantities in the factory/works for specified MS plate pipes based on thickness respectively.

vi. X-ray screening.

vii. Mechanical Tests of finished pipes as per IS 3589.

3.2.12. The pipes manufactured with ERW and SAW process are to be tested to the following requirements in the presence of Engineer or his representative.

i. Mechanical Tests as per IS:3589 with method of sampling as per IS:4711.

ii. The tolerances outside diameter for pipe body and pipe ends and thickness tested according to IS:3589.

iii. Each pipe shall be hydraulically tested to at the manufacturer's works to a minimum test pressure as specified in the Bill of quantities for specified thick MS plate pipes respectively.

iv. Radiographic testing of the pipe welds for 10% of the welded length as per IS:4853 for the sample of pipes.

v. 100% Ultrasonic Testing for factory and field welded joints.

3.2.13. Welding

The welding shall be of the best workmanship free from flaws, burns, etc. and the Contractor shall provide for his own electrodes and equipments, ovens to keep the electrodes at the desired temperatures and dry. In order to maintain a good standard in welding, welders shall be tested by the Contractor and approved by Engineer-in-Charge before they are entrusted with the job. Qualification standard for welding procedures, welders and welding operation shall conform to the requirements of IS : 7307 and IS : 7310. Periodical tests as regards their efficiency shall also be taken at intervals of about 6 months and those found inefficient shall be removed from the job as per the instructions of Engineer-in-Charge. Only those who pass the test, shall be posted on the job. If an incompetent welder has already welded some pipes, all welding done by him previously shall be fully checked by X-ray in addition to the regular X-ray inspections. The defects if any, shall be set right to the satisfaction of the Engineer-in-Charge. All such check tests and rectifications of defects shall be entirely at the cost of the Contractor. No pipes or steel sections shall be erected unless the work of the welder concerned has been proved to be satisfactory. Specially selected welders shall do site welds.

A record shall be maintained showing the names of welders and operators who have worked on each individual joint. Hand welding shall preferably be carried out by a pair of welders so that, by observing proper sequence, distortion can be avoided. A joint entrusted to a particular individual or a pair shall be as far as possible, completed by them in all respects, including sealing run. No helper or other unauthorized person shall be permitted to do any welding whatsoever.

The welded joint after welding should not become brittle or sensitive to blows and there should be no loss of toughness due to welding or heat treatment. The material after welding and heat treatment is to be tougher than the base metal and is to retain its original ductility. No allowance will be made for thinning of weld and the weld should in no point be less than the nominal thickness of plate.

Upon receipt of the order and prior to the start of fabrication, the Contractor shall submit to the ENGINEER-IN-CHARGE for his approval the ``welding procedure'' he intends to use in the shopwork. Similarly, prior to the start of the field welding, procedure for the field welding must be submitted to the ENGINEER-IN-CHARGE for his approval. Manual welding shall be adopted only when machine welding is not possible.

3.2.14. Radiograph of Welded Joints

Radiograph of welded joints at Shop

Shop weld in pipes, specials shall be radiographed as per requirements as below:

As soon as practicable, after welding is done, every longitudinal and circumferential welded length minimum 10% (ten percent) length of the weld at random for each pipe shall be radiographed, to detect welding defects as per the requirement of IS 4853 and as directed by ENGINEER-IN-CHARGE. This 10% sampling will be random and ensure 100% coverage of junctions of longitudinal and circumferential joints. If the results of such radiography fails to confirm to the requirements, the contractor shall carry out as directed additional or 100 percent radiography test for the pipeline. All fabricated specials shall be 100 % radiographed.

Radiograph of Welded Joints at Field

The field welded joint shall be 10% radiographed. This sampling will be random and ensure 100% coverage of circumferential joints, joints with specials, flanges etc. If the results of such radiography fail to conform to the requirements, the Contractor shall carry out 100% radiography test for the pipe as directed at the Contractor’s cost to the satisfaction of the ENGINEER-IN-CHARGE.

Requirements of Radiography

The weld ripples or weld surface irregularities and slag etc., on both inside and outside shall be removed by any suitable mechanical process to a degree such that resulting radiographic contact due to any remaining irregularities cannot mark or be confused with that of objectionable defect. The radiograph shall be made in strict accordance with the latest requirements and as per the latest and most efficient technique either with X-ray or gamma ray equipment. The safety requirements during radiography shall be in accordance with IS 2598.

The radiographs are to be marked in such a way that the corresponding portion of the welded seam and the welder can be readily identified. All radiographs will be reviewed by the Engineer-in-Charge to identify the defects and determine those which requires rectification. Defects that are not acceptable shall be removed by chipping, grinding or flame gouging to sound metal and the resulting cavities shall be welded. After rectification, the joint is to be radiographed again to prove the quality of the repair. The radiographs will be judged as acceptable or unacceptable by the Engineer based on the latest standards prescribed by relevant Indian Standard specification.

All X-rays shall be taken with equipment and by personnel of the Contractor. Films shall be developed within 24 hours of exposure and be readily accessible at all times for inspection by the Engineer. The Contractor shall provide for the use of the Engineer suitable X-ray viewing equipment. X-ray films shall be properly maintained by the Contractor. A complete set of radiographs and records as described in IS : 2595, for each job shall be retained by the Contractor and shall be handed over to the EMPLOYER on completion of the Contract. All films shall be identified by the number and chart prepared indicating location of any work associated with the pipe erection and such inspection shall be performed by the Radiographer at the discretion of the Engineer.

Radiographic Inspection of welded joints :

All welded joints to be radiographed shall be examined in accordance with

IS 2595 - Code of Practice for Radiographic Testing

IS 4853 - Recommended Practice for Radiographic Examination of Fusion Welded Butt – Joints in Steel Pipes

IS 1182 - Recommended Practice for Radiographic Examination of Fusion Welded But – Joints in Steel plates.

IS 2598 -Safety Code for Industrial Radiographic Practice.

Radiographers performing radiograph shall be qualified in accordance with SNT-TC-1A . Supplements and Appendices “Recommended Practice for Non-destructive Testing Personnel Qualification and Certification” published by the American Society for Non-destructive Testing as applicable for the technique and methods used.

Final acceptance of radiographs shall be based on the ability to see the prescribed penetrometer image and the specified hole.

Sections of welds that are shown by radiography to have any of the following types of imperfections shall be judged unacceptable and shall be repaired.

i. any type of crack, or zone of incomplete fusion or penetration,

ii. any elongated slag inclusion which has length greater than 6 mm

iii. any group of slag inclusion in line that have an aggregate length greater than thickness in a length of 12 times thickness, except when the distance between the successive imperfections exceeds 6 L where L is the length of the longest imperfection in the group, rounded indications in excess of that specified by the acceptance standards given earlier.

3.3. In lining

3.3.1. In lining of M.S. Pipes is to be done in a factory to conform to IS: 11906-1986.

3.3.2. The cement mortar used for in lining shall be of 1:2 proportions by volume.

3.3.3.Cement used in the work shall conform to IS: 269-1976 / IS: 8112 / IS: 12269

3.3.4.The sand shall conform to Clause 2.2 of IS: 11906-1986.

3.3.5.The thickness of in lining shall be minimum of thickness specified in Bill of quantities & tolerance can be +3 mm. with no minus tolerance.

3.3.6.The in lining of steel pipe shall be done with thickness specified in Bill of quantities using machine mixed cement mortar 1:2 proportion by volume and applied by the process of spinning, with a reinforcement of 6 mm. dia. M.S. rings 6 Nos. on internal surface on each end of pipe in a length of 230 mm. and the reinforcement shall conform to I.S. 432 (Part-I).

3.3.7.A length of about 150 mm shall be left exposed without applying mortar inside and outside to facilitate field welding of pipes.

3.3.8.After completion of in lining the pipes, required curing by water shall be done as per IS:11906.

3.3.9.The samples for compression tests on cement mortar shall be made as per IS: 516 on 7.06 cm / 10.0 cm cubes. At least 6 test cubes of cement mortar shall be drawn on each day of work. Of each set of 6 cubes, three shall be tested at 7 days age and three at 28 days age. The average strength of the specimens tested shall not be less than the strength specified in the relevant IS code. The laboratory test results shall be tabulated and furnished to the Engineer.

3.3.10. The following records are to be maintained for in lining in factory:

a) Grading of aggregates.b) Mix used c) Cube testing recordd) The date of inlininge) Serial No. of pipef) Test pressure of pipe

3.4. Out coating of the pipes:

3.4.1. Outcoating shall be done in the factory as per IS: 9012-1978.

3.4.2. Outcoating shall be done after inlining is cured for 3 days.

3.4.3. Outcoating shall be done with thickness specified in Bill of quantities by concreting or guniting or brush coating using cement mortar 1:3 by volume. The volume proportion shall account for bulkage in sand.

3.4.4. The wire mesh used for outcoating shall be 50 mm X 50 mm with 3 mm wire conforming to IS:1566-1982.

3.4.5. The rebound percentage as provided in IS: 9012-1978 has to be taken into account by the contractor.

3.4.6.The samples for compression tests on cement mortar shall be made as per IS: 516 on 7.06 cm / 10.0 cm cubes. At least 6 test cubes of cement mortar shall be drawn on each day of work. Of each set of 6 cubes, three shall be tested at 7 days age and three at 28 days age. The average strength of the specimens tested shall not be less than the strength specified in the relevant IS code. The laboratory test results shall be tabulated and furnished to the Engineer.

3.4.7.The following records are to be maintained for out coating in factory.i) Grading of aggregatesii) Mix usediii) Cube testing recordiv) Date of outcoating

4. Fabrication of M.S. Specials & Fittings

4.1. The MS specials and fittings shall be fabricated from MS plates or MS sheets conforming to specification IS: 2062-Grade-A/B. The minimum thickness of the plate shall be as specified in the bill of quantities. Special attention is directed to these specifications, which cover physical, chemical, manufacturing and mechanical equipments. Test certificates for plates and other materials shall be submitted by the contractor to the Engineer for approval before fabrication of M.S. Specials and fittings is commenced. No material shall be used in the fabrication of any pipe or fittings, which has not been properly inspected by the Engineer.

4.2. The manufacture of MS specials and fittings shall be carried out as per I.S. 7322-1985. Manufacturer's equipment for all specials, such as welding, flame cutting and other operations shall be of a standard and quality necessary to produce specials meeting the specification. Equipment, in general, shall be in good condition and shall be modern as judged by the standards of the industry.

4.3. The longitudinal seams of fabricated specials shall be butt-welded; shop girth seams shall be butt-welded.

4.4. All edges cut to size shall be uniform and smooth. Those edges to be welded that are prepared by flame cutting shall be free from scale and slag accumulations.

4.5. Edges of plates to be jointed by an automatic welding machine shall be formed to the shape required for the particular welding process and automatic welding machine be employed in carrying out the agreed procedure. Edges of plates to be jointed by manual welding shall be formed to the shape required by the Engineer in accordance with the drawings. The resulting edges for welding shall be uniform throughout the entire length of the plate and shall be to a straight line.

4.6. Minor defects in the welds of electric- welded pipe and specials such as sweats or leaks, shall be repaired. Repairs of this nature shall be made by completely removing the defect, cleaning the cavity and then welding. The workmanship involved in the repair is subject to approval of the Engineer.

4.7. Special sections having butting plates of different thickness shall have the heavier plate sufficiently beveled so that the apex of the weld groove shall correspond with that of the lighter plate.

4.8. All lap breaking, rolling, cleaning of plate surfaces to be welded and fitting-up operations, as well as the qualification of the welding operators, welding procedure, automatic welding, manual welding and correction of welds in pipes and specials shall be in accordance with the relevant I.S.Specifications.

4.9. Reshaping MS pipes and special, after they are manufactured shall be done by rerolling or by pressure. Reshaping of pipe by excessive hammering or dropping will not be permitted.

4.10. Diameter of all bolts circle of the flanges shall comply with the relevant IS:1538-1993 for flanged pipes. Bolts and nuts shall be in accordance with I.S.1363-1967.

4.11. Flanged pipes

4.11.1. Flanged pipes and specials of varying length and diameter shall be externally and internally lined with mortar. Dimension of the flanges, welding details and welding procedure shall be in accordance with the I.S. 7322-1985. Flanges shall be welded to a section of the pipe before machining. Faces of flanges shall be machined. The pitch circle shall be as per I.S. 1538-1993. The minimum thickness of flange shall be 32mm after machining.

4.11.2. Flanged branches

4.11.2.1. Flanged branches shall be fabricated in accordance with the general specification and to the Engineer's requirements. Wall opening shall be formed by welding fabricated structural steel of approved design to the steel cylinder and shall be lined internally and coated externally.

4.11.2.2. Flanged branches for air and scour valves shall be welded into pipe in the required position. The branch for an air valve shall be vertical and at right angle, to the longitudinal axis of pipe. The invert of the branch for a scour valve shall be horizontal and at right angles to the axis of pipe and shall align with the invert of the barrel of the main pipe.

4.11.2.3. All flanges shall be machined to standard thickness, square to the axis of the pipe and the bolt hole shall be drilled evenly off centre and true to the pitch as per IS:1538-1993.

4.11.2.4. Dimension of the flanges, welding details and welding procedure shall be in accordance with the I.S. 7322-1985. The minimum thickness of flange shall be as mentioned in the Bill of Quantities.

4.12. Bends

MS Bends to provide change of alignment in main laying shall be manufactured to suit the site conditions from completed and tested pipes by angle cutting the barrel or by such other standard procedure and rewelding. Bends shall be lined internally and coated externally as given in the schedule. The bends shall be fabricated as per specification drawing.

4.13. Tapers

MS Tapers shall be manufactured out of steel plates and lined internally and coated externally. The tapers shall be suitable for connections to the sluice valves or flanged tail piece on the side and to MS Pipe on the other side. Stiffener rings shall be provided to afford rigidity to pipe. They shall be manufactured generally in accordance with IS: 7322-1985 and the dimensions shall be as per specification drawing.

4.14. Tolerance for steel fittings shall conform to the requirements of IS 7322-1985.

4.15. Notwithstanding anything said, elsewhere, the Tenderer shall furnish the thickness of the steel plate used and other relevant details and shall get the approval for these details from the Engineer, before fabrication.

4.16. Welding Process of manufacture of MS Specials and Fittings.

4.16.1. Any of the following process shall be employed for butt welding

(a) Automatic submerged arc welding;(b) Automatic metal arc welding with covered electrodes;(c) Automatic metal arc welding with bare electrodes;(d) Manual metal arc welding as per IS 9595-1980.(e) Electric resistance welding

4.16.2. All electrodes shall conform to IS 814-1991.

4.17. Thickness of M.S. Plate.

Minimum thickness of M.S. Plate shall be as per bill of quantities specified in the bid documents.

4.18. Inlining and Outcoating of M.S. short pipes, specials

(i) General and Thickness of shortcreting The guniting is to be carried out at the factory. Care shall be taken to see

that the pipes specials are perfectly in shape while the inlining and outcoating is being given.

The thickness of inlining shall be as specified., and that of outcoating shall be as specified in the bill of quantities.

(ii) Internal dia of the pipeline proposed for lining actually cleaned, mortar lined in accordance with the specifications and accepted by the Engineer-in-charge will be measured along the centre of the pipeline. No deduction shall be made for small opening at manholes, air valves, cross connections etc, except sluice valve and expansion joints etc. The Contractor shall provide all assistance to the Engineer-in-charge for taking measurements. The rate for the finished item of pipe includes mobilising of machinery for work, supply of material, manpower for the work, providing access to the site, making access openings in the pipeline at gaps for machine and feeding the mortar, providing operational platform, cleaning the pipelines and removing the debris from the pipeline, machine mortar lining and mechanically trowelling, curing, controlling temperature in the pipeline during the progress of the work, closing the gaps guniting/concreting such portion for pipeline, establish working conditions in the pipeline and thereafter to prevent damages to mortar lining, inspection and testing, commissioning and any other incidental items of works as per scope of work and specifications.

(iii) Reinforcements for inlining and outcoating:

The reinforcement used shall be MS Fabric 50 mm X 50 mm X 3 mm conforming to I.S. 1566-1982. The welded fabric shall be bent to proper shape to conform as neatly as possible to the surface of the pipe. Adjacent sheets of fabric shall lap atleast 80 mm. and shall be securely fastened together by binding wire at intervals not exceeding 30 cm.

(iv) Proportion of mix

The proportion of cement and sand shall be 1:2 by volume for inlining and 1:3 for outcoating. The contractor shall take into account the rebound percentage of cement mortar as per I.S. 9012-1978 while quoting the rates.

(v) Material:

The material shall conform to the specifications prescribed for cement, sand and water under Clause 2 of IS: 11906-1986 and Clause 3 of IS: 7322-1985 and IS: 9012-1978 of manufacture of steel pipes and fittings, inlining and outcoating with cement mortar.

(vi) Procedure: The guniting shall conform to IS: 9012-1978, Dry Mix Process.

Before guniting, all steel surface shall be thoroughly cleaned of paint, rust, scales, grease, loose or disintegrated concrete or such other material as are likely to impair the bond between the surface to be encased and the gunite.

The pressure in the lower chamber of the "Cement Gun" shall be sufficient to produce a nozzle velocity of 115/150 metres per second when a tip with 19 mm. opening is used. The velocity shall be steady at all times.

The compressor used shall be of adequate capacity to maintain a pressure of atleast 2.15kg./Sq.Cm. at the gun end.

The nozzle shall be held at such a distance (0.67 to 1 metre) and position that the stream of flowing materials shall impinge as nearly as possible at right angles to the surface being gunited. All deposits of loose and scale removed prior to placing any layer of gunite. Should any deposit of sand be covered with gunite, this gunite shall be removed and redone.

The gunite shall be shot in one coat to the proper thickness. At the edge of any section where the operations are more or less temporarily suspended, the gunite shall be brought to a tapered edge extending back for not less than 30 cm. Prior to placing the gunite on the adjacent section, the upper surface of this tapered edge shall be cleaned by scraping and blowing away all rebound and washing down with water and air blast. No right angled joints shall be allowed in the gunite.

The contractors shall provide proper arrangements for blowing all rebound from the area being shot. No gunite shall be placed over rebound and in

case of such conditions arising, the contractors shall remove at their own cost any gunite so placed. Rebound material deposited in mounds shall be removed from the site of work, to places directed by the Engineer. To remove the rebound, the surface of the gunite shall be carefully cleaned with an air jet and suitable tools at such periods after shooting as the Engineer may deem advisable. In no case, however, shall the rebound remain on the completed surface for more than 12 hours. The scraping of rebound must be done in such a manner as not to disturb gunite and to provide a uniform and proper finish to the surface.

The contractors shall employ experienced men for this work. No nozzle man will be deemed experienced unless he has done considerable work previously, where the work was of a similar type or has otherwise proved his qualifications to the satisfaction of the Engineer by experience on other equally important work.

The work shall be supervised by properly trained foreman of the contractor. No one shall be considered as capable of acting as foreman on a job if he has not had active charge of placing gunite lining previously.

(vii) Curing:

The gunite shall be kept thoroughly wet for a period of atleast 7 days after guniting as specified in IS:9012.

4.19. Tests

Each MS special or MS fitting shall be subjected to tests as per Clause 8 of IS: 7322-1985 before inlining and out coating. The hydraulic test pressure shall be as specified in the bill of quantities as the case may be for the MS specials manufactured for specified thick MS plate respectively. Dye penetration test as prescribed in IS-7322 of 1985 is acceptable in lieu of hydraulic test for bends only.

4.20. Handling of Specials

4.21.Coated specials that are to be stored on supports shall bear on the uncoated ends only. If bearing on coating is employed the support shall be not less than 20 cm wide and so arranged to prevent damage to the coating.

4.22.During transporting the fittings, coating shall be protected from damage by bearing on well padded bolsters not less than 20 cm wide and placing strips of heavy belting or other approved sheet materials not less than 20 cm wide under all ropes or fastening.

5. Tolerance

5.1. Tolerance for straight MS pipes and fittings shall as follows:

5.2. The tolerance on the dimensions of the MS pipes and MS specials shall be as specified in 12.3 and 12.4 of IS: 3589-2001. Finished pipe sections shall be truly straight with walls parallel to the axis of the pipe and be not out of the alignment by more than 0.2 percent of the total length. Straight pipe shall not vary from the specified overall length by plus 10 mm

or minus 0 mm for length upto and including 6 M. For MS specials and fittings, it shall be as per IS: 7322-1985.

5.3. The outside diameter of the pipe shall not vary by 1% in case of seamless pipes and 0.75% in case ERW and SAW pipes.

5.4.For MS specials and fittings the tolerances shall be as per IS:7322-1985. No negative tolerance for thickness of MS pipes is allowed.

6. Epoxy Application:Wherever in lining is not provided in MS pipes, the inner surface of the pipe shall be coated in 2 layers over a primer coat with epoxy paint both of food grade confirming to relevant IS specifications.

7. Coal Tar Epoxy Application

7.1. The following MS steel pipe work shall be protected by use of coal tar epoxy.

i) All chamber pipe work.

ii)Articulation pipe work either side of line valve chambers.

iii) All Tee’s and Branches of concrete coated pipelines.

iv) Where specifically shown in the drawings enclosed with the bid documents.

7.2. The coal tar epoxy shall be a black colour two pack factory spray applied coating in accordance with BS:5493 – Type KF3. Steel surface shall be prepared in accordance with the manufacturer’s instructions, but as a minimum shall be abrasive blast cleaned to BS: 7079, Grade SA 2 ½, 75 – 100 micron profile. The first layer shall be applied within 2 hours of surface preparation, before flash rusting can occur.

7.3. The final dry film thickness shall exceed 500 microns (0.5 mm) and may be achieved by applying several coats provided that the coats are applied within 8 hours of each other. Any surface blooming shall be removed by light abrasion before recoating. No coating shall be applied if the surface temperature of the pipe exceeds 350 C.

7.4. Within 3 days of applying the epoxy, a further chlorinated rubber ‘travel coat’ having a dry film thickness of 200 microns (0.2 mm) shall be applied. The chlorinated rubber shall be in accordance with BS: 5493-Type HF1.

8. Polyurethane Coatings

8.1. All above ground steel pipe work and ring girders are to be protected with a white or cream colour two pack polyurethane coating in accordance with BS: 5493 – Type KF2. The factory applied coating is to be stopped 200 mm back from the spigot and socket joint and then made up on site following testing of the joint.

8.2. The cured polyurethane coating shall have a shore hardness of D 75 and impact resistance of 20 Nm. It shall be suitable for service in surface temperatures of upto 700 C.

8.3. Both factory and site application is to be by twin component airless spray equipment. Surface preparation shall be in accordance with the manufactures instructions, but a minimum shall be abrasive blast cement to BS 7079, Grade Sa 2.5, 75 – 100 micron profile. The first coating layer shall be applied within 2 hours of surface preparation, before flash rusting can occur. No coating shall be applied if the surface temperature of the pipe exceeds 350 C.

8.4. The final dry film thickness shall be a minimum of 300 microns. This may be achieved by applying several coats provided that the coats are applied within 2 hours of each other. Any surface blooming shall be removed by light abrasion before recoating.

9. Expansion Joints

9.1. Expansion joints are designed to allow for thermal induced movement in above ground pipelines. They are to be installed along the pipeline at regular intervals of not greater than 80 m. Expansion joints shall be welded on to pipelines at points indicated on the drawings. They shall be fabricated as shown on the drawings and protected with a 300 microns thick polyurethane coating applied in accordance with specification clause 12.

9.2. Following installation and testing the expansion joints shall be protected by a polyurethane coated cover fabricated from 3 mm thick mild steel plate. The cover shall be fabricated in two halves for ease of maintenance and held together by 5 No. galvanized M 20 nut and bolt sets equally spaced along each of the joint flanges. The flanges themselves shall each be 20 mm thick by 100 mm wide. The cover edges in contact with the pipe shall be protected with a 50 mm by 25 mm SBR rubber ‘U’ section having a wall thickness of 10 mm.

10. Ring Girders

10.1. Ring girders are to be used to support large diameter above ground pipe work. They shall principally be fabricated from channel sections of Grade-B steel to IS:2062 and be supported by either rectangular concrete plinths or pipe bridge supports. Ring girders are usually installed 1 m behind each welded joint, i.e. at 8 m intervals along the pipeline.

10.2. Ring girders shall be designed and fabricated as per approved drawings and where possible, factory welded to the pipe. All surfaces apart from the stainless steel and PTFE pads are to be protected with a 2 mm thick polyurethane coating which shall be applied in accordance with specification clause 12. Any damage to the coating is to be made good in accordance with the manufacturer’s instructions.

10.3. After the ring girder has been welded to the pipe it shall be filled with hot bitumen through one of two 10 m dia holes in the crown of the girder. After the bitumen has set the holes are to be welded up.

10.4. The entire slide assembly shall meet the following specifications

i) The coefficient of friction between the stainless steel and PTFE pads shall be less than 0.1 when carrying a load of 250 kN and having a surface temperature of 700 C.

ii)The Stainless steel pad shall be highly polished grade 316 steel and the PTFE shall be Type UA/1 to BS 6564: Part-2.

11. INSPECTION AND TESTS OF INLINING

1. Responsibility of Employer and contractor

The entire procedure of applying cement mortar lining shall be subject to continuous inspection by the Engineer-in-Charge but such inspection shall not relieve the Contractor of the responsibility to furnish material and perform work in accordance with the specifications. All cement mortar lining not applied in accordance with the specifications shall be subject to rejection by the Engineer. Lining so rejected shall be removed and replaced by the Contractor at the expense of the Contractor.

2. All places accessible to Engineer

The Engineer shall have free access to all areas, places or facilities concerned with the furnishing of material or the performance of work.

3. Contractor to assist Engineer

The Contractor shall furnish the Engineer reasonable assistance, without charge, in carrying out the inspection duties and specifically in obtaining information with respect to the character of material used and the progress and manner of the work.

4. Pipe Inspection ProcedureThe Engineer shall inspect the pipeline following the application of the cement-mortar lining to identify defective areas in the lining, to determine compliance with the specifications.

4.1. Pipe InspectionA visual inspection of the lined pipe interior shall be made by the Engineer to determine the quality of the lining and to identify defective areas in the lining for repair. For rendering layer thickness test, the Contractor may use magnetic blocks of 15 mm. thick and attach to the pipe on diametrically opposite points inside the pipeline at locations as may be directed by the Engineer. These blocks shall be removed next day and the holes shall be closed next day by hand application after lining thickness is measured.

The lining thickness can also be measured by drilling holes in hardened mortar at diametrically opposite points by a depth gauge. Such holes shall then be closed by hand application of mortar. The Contractor may suggest any method for testing thickness of layer to the satisfaction of the Engineer.

5. Defective LiningDefects in cement-mortar lining include, but are not limited to, sand pockets, voids, oversand areas, excessively cracked and dummy areas, areas in lining thinner than specified, and areas of unsatisfactory surface finish.

6. Repair of Defective Lining

Small defective areas shall be repaired by manual removal of defective lining and by hand reapplication of mortar lining, defective areas encompassing the full diameter of the pipe where lining shows evidence of failure. Undue irregularity of inferior workmanship requires excessive patching or shows segregation of or deficiency in cement content, the Contractor shall remove the mortar lining in such faulty sections, reclean the pipes and reline in accordance with the specifications such portions at no extra cost to the Board. Engineer's decision regarding the above shall be final and binding on the Contractor.

7. Lining Cracks

Temperature and shrinkage crack in the mortar lining less than 1.6 mm. wide need not be repaired. Cracks wider than 1.6 mm. need not be repaired if it can be demonstrated to the satisfaction of the Engineer that the cracks will heal autogenously under continuous soaking in water. The autogenous healing process may be demonstrated by any procedure that keeps the lining of the pipe continually wet or moist.

8. Protection of Lining

Every precaution shall be taken to prevent injury to the lining. Should the lining be damaged at any time prior to completion of the contract, such damage shall be repaired conforming to the specifications at the Contractor's expense.

9. Performance Criteria - Surface finish

The Hazen-William `C' factor shall be the criteria for determining the acceptability of surface finish of cement mortar lining for acceptable performance guarantee (C) shall not be less than 120 for the entire length of the contract or 130 for straight reaches. The flow measurement shall be by pitot meter and pressure measurements shall be by pressure gauges.

10. Testing Equipment and testing of pipes

10.1. The pipes manufactured with spirally welding process are to be tested to the following requirements in the presence of Engineer-in-Charge or his representative.

i. Continuous monitoring of dia and forming.

ii.Radiographic testing of the pipe welds for 10% of the welded length as per IS:4853 for the sample of pipes.

iii. 100% Ultrasonic Testing for factory and filed welded joints.

iv. Visual inspections of all pipes from inside and outside for permissible tolerances as per IS:3589.

v.All the pipes are to be subjected to hydrostatic test pressure of minimum 30 Kg/Sqcm, 30 Kg/Sqcm and 24 Kg/Sqcm in the factory/works for 20.0 mm, 18.0 mm and 14.2 mm thick MS plate pipes respectively.

vi. X-ray screening.

vii. Mechanical Tests of finished pipes as per IS 3589.

11. The pipes manufactured with ERW and SAW process are to be tested to the following requirements in the presence of Engineer or his representative.

(i) Mechanical Tests as per IS:3589 with method of sampling as per IS:4711.

(ii) The tolerances outside diameter for pipe body and pipe ends and thickness tested according to IS:3589.

(iii) Each pipe shall be hydraulically tested to at the manufacturer's works to a minimum test pressure of 30 Kgs/Sqcm, 30 Kgs/Sqcm and 24 Kgs/Sqcm for 20.0 mm, 18.0 mm and 14.2 mm thick MS plate pipes respectively.

(iv) Radiographic testing of the pipe welds for 10% of the welded length as per IS:4853 for the sample of pipes.

(v) 100% Ultrasonic Testing for factory and filed welded joints.

12. 10% of the field joints as well as shop joints shall be tested Radiographically as per IS 4853. However the specials shall be 100% radiographed.

13. The contractor shall provide and operate suitable equipment capable of conducting the specified hydrostatic test pressure to the inside surfaces of the Pipes and of sustaining the pressure for the required periods.

14. Inspection openingsM.S. Inspection openings using specified thick M.S. Plate of I.S. 2062-Grade-A/B as specified in Bill of quantities should be fixed as directed by the Engineer-in-Charge on bends, tapers etc.

15. The hydraulic test pressure

Each pipe shall be hydraulically tested at the manufacturer’s works before the pipe is coated, wrapped and lined in accordance with the IS 3589:2001 standards.

The hydraulic test pressure shall be the pressure calculated as per the following formula:

12. PIPE LAYING AND CONNECTED WORKS

1. GENERALThe specification for manufacturing, laying, jointing and testing of MS Pipes manufactured with Electric-Resistance Welding (ERW) or Submerged Arc Welded (SAW) to IS:3589-2000 and IS:5822-1994.

These specifications cover the work of laying MS pipeline, underground and above ground, including Civil Works required for the same.

The main works covered under these specifications:-

a) Earth work excavation i) Excavation in trenches for laying pipeline etc.ii) Excavation for foundation of anchor blocks, thrust blocks, pedestals, piers, culverts, valve

chambers etc.b) Shoring and strutting. c) Bailing out water.d) Concrete, plain and R.C.C. in anchor blocks, thrust blocks, pedestals, piers, culverts etc.e) Transporting assembling pipes, specials, valves, appurtenances etc.f) Providing Class-S bedding and surround with granular material i.e. gravel and Class-A bedding

with M20 grade concrete as per the relevant drawings enclosed.g) Lowering, laying and jointing of specified dia. (inside dia after lining with specified thick cement

mortar) Pipeline with necessary specials, fittings and valves.h) Providing inlining and outcoating with cement mortar for the field welded joints.i) Cleaning and painting M.S. Pipes, specials etc., externally for the pipeline laid above ground and

wherever necessary.j) Refilling of trenches, transporting surplus earth and clearing the site of all debris.k) Pressure testing of pipeline with specified pressure at site

2. PIPELINE ROUTE SURVEY Before commencement of excavation for pipe trench, the CONTRACTOR shall carryout full

route survey and preparation of pipeline profile drawings, all in accordance with the construction programme, subject to Engineer-in-Charge approval.

Pipelines route shall be designed to have the following minimum safety clearance between the edge of pipe and existing road/ plot/ structure unless otherwise prior approval is taken. In case of pipe lines to be laid in the private lands in cross country, the prior permission and notices shall be obtained from the concerned authorities with prior notification.

All survey work shall be referred to the National Grid, Universal Traverse Mercator (UTM) or the Survey of India Datum as directed by the Engineer-in-Charge.

The survey shall be carried out using calibrated survey equipment approved by ENGINEER-IN-CHARGE. The survey work shall be executed by qualified land surveyor approved by ENGINEER-IN-CHARGE.

The CONTRACTOR shall set out the route of the pipeline in accordance with the drawings approved by the Engineer-in-Charge. The route shall be marked by suitable wooden poles set in to the ground. The poles shall be set along centre line of the pipeline at intervals of 50m chainage, at every bend, air valve, washout or valve chamber and at all physical obstructions (existing chambers, excavations, etc.).

From the results of this survey, the CONTRACTOR shall prepare the pipeline alignment and profile drawings. Pipeline profile drawings shall be presented at a a vertical scale of 1:125 or as directed by ENGINEER-IN-CHARGE. For lay out plans shall be prepared for 1:1250 scale All drawings shall be submitted to the ENGINEER-IN-CHARGE for approval on ISO size A1 paper prints.

The CONTRACTOR shall plot on these drawings the detailed routes and profiles of the pipelines. The profile shall comply with the requirements of pipe shell thickness, pipeline minimum cover, minimum gradient and spacing of air valves, washout and valve chambers and the location of the marker posts etc. according to typical drawing. The distance between marker posts from any bend (Change of Direction) of the pipeline to the next post of the straight runs, and all post/s thereafter shall be at 500 Meters interval. The distance between the last post of the straight run and the next bend shall be as per Engineer-in-Charge’s approval. As required, the Engineer-in-Charge reserves right to change the distances of marker post/s between bends to compensate for any distance less than 500 M. The route profile shall be plotted under the relevant section of the pipeline route plan. The route plan shall show a strip of land 500m wide, along the proposed pipeline route.

The profiles shall also show the chainage of the pipeline at the points of ground level measurements and at any change in profile. The CONTRACTOR shall determine the invert level of the pipeline at the points of level measurement and mark these levels on the drawings. The diameter and details of the pipeline including thickness shall also be shown.

ENGINEER-IN-CHARGE shall approve or otherwise amend the route or profile of the pipelines and the CONTRACTOR shall revise the drawings accordingly. The revised approved drawings shall be marked "APPROVED" and thereafter shall become the Contract Drawings for the pipeline construction. These drawings may also then be used by the CONTRACTOR for finalizing the pipeline materials order.

The survey shall include information on all the existing services and facilities such as roads, power lines and cables, sewers, irrigation pipelines, water pipelines, oil/gas pipelines, drainage channels and culverts, and plantations, within a 20m wide strip centered on the pipeline route.

The existing underground utilities traversing the pipeline route shall be exposed by hand excavation and their exact lines and levels shall be included in the results of the survey. The CONTRACTOR shall record by site investigation the exact lines and levels of the pipelines that are to be connected to the proposed pipeline.

The results of the survey shall be presented on diskette to the ENGINEER-IN-CHARGE as a Auto CAD or Micro station GIS environment drawing compatible with the Client's existing/proposed GIS system to the approval of the ENGINEER-IN-CHARGE.

The cost for the pipeline survey shall be borne by the Contractor .

3. EXCAVATION OF TRENCHES AND PITS

Excavation for trenches shall be carried out for a maximum of four pipe lengths in advance of the pipe laying or as determined by the ENGINEER-IN-CHARGE. The trenches shall be excavated to the required line and level as shown on the drawings or as approved by ENGINEER-IN-CHARGE, and shall, at all times, be drained and braced to ensure safe and efficient pipe laying. In locations where services, ruins, or other structures are near the pipeline route, hand excavation only will be permitted, subjected prior to approval from the Engineer-in-Charge.

3.1. EXCAVATION

Excavation shall be required to be done for the following works:-

(a) Excavation for underground pipelines.

(b) Excavation for foundation of piers, abutments, walls, footings, pedestals, chambers for valves etc.

(c) No separate payment shall be made for removal of shrubs, grass, large and small bushes, hedges, trees, stumps and stems of tree cut, roots, fencing including posts, gates, portion of old masonry parapet walls.

3.1.1. Classification

The Excavation work shall be classified into the following categories by inspection of faces of cutting.

(a) SoilThis shall comprise top soil, turf, land, sill, loon, day, mud, peat. Mack cotton toil, loft shale or loose morrum, a mixture of these and similar material which yields to the ordinary application of pick, spade and/or shovel, rake or other ordinary digging implement. Removal of gravel or any other nodular material having dimension in any one direction not exceeding 75 mm occurring in such strata shall be deemed to be covered under mil category.

(b) Ordinary Rock (not requiring blasting this shall include):

(i) Rock types such as laterites, shales and conglomerates, varieties of limestone and sandstone etc., which may be quarried or split with crow ban, also including any rock which in dry state may be hard, requiring- blasting but which, when wet, becomes soft and manageable by means other than blasting;

(ii) Macadam surfaces such as water bound and bitumen Air bound; soling of roads, paths etc. and hard core; compact' morrum or stabilized soil requiring grafting tool or pick or both and shovel, closely applied; gravel and cobble stone having maximum dimension in any one direction between 75 and 300 mm;

(iii) Lime concrete, stone masonry in lime mortar and brick work in lime/cement mortar below ground level, reinforced cement concrete which may be broken up with crow bars or picks and stone masonry in cement mortar below ground level; and

(iv) Boulders which do not require blasting having maximum dimension in any direction of more than 300 mm, found lying loose on the surface or embedded in river bed, soil, talus, slope wash and terrace material of dissimilar origin. (49 Earthwork, Erosion Control and Drainage Section 300.)

(c) Hard Rock (requiring blasting)

This shall comprise:(i) Any rock or cement concrete for the excavation of which the use of mechanical

plant and/or blasting is required;(ii) Reinforced cement concrete (reinforcement cut through but not separated from

the concrete) below ground level; and(iii) Boulders requiring blasting.

(d) Hard Rock (blasting prohibited)Hard rock requiring blasting as described under (c) but where blasting is prohibited for any reason and excavation has to be carried out by chiselling, wedging or any other agreed method.

(e) Marshy SoilThis shall include soils like soft clays and peats excavated below the original ground level of marshes and swamps and soil excavated from other areas requiring continuous pumping or bailing out of water.

The classification of excavated material shall be decided by the Engineer-in-Charge and his decision shall be final and binding on the Contractor. Merely the use of explosives in excavation will not be considered as a reason for higher classification until blasting is clearly necessary in the opinion of the Engineer-in-Charge.

3.1.2. Excavation for laying underground pipeline

For laying underground pipeline, trenches shall be taken by the contractors as shown in the relevant drawing. The pipeline shall be laid to the correct level according to the longitudinal section. It is incumbent on the contractors to follow a planned continuous procedure of work in respect of excavation, pipe laying, fixing appurtenances and refilling the trenches so as to ensure completion of work in time and repairing of any roads excavated for this purpose by filling with suitable material to original grade in the shortest possible time. The daily progress of excavation work for preparing trenches shall match with the refilling of trenches in the completed portion as far as possible.

The dimensions of the trench for laying the MS pipes shall be as shown in the specification drawings. Payment for excavation shall be made on quantity basis as per the actual dimensions of the trench excavated subject to the condition that the quantity shall be limited as per the trench cross sections given in the specification drawings.

Welding pits and pits at welding joint shall be filled up with granular material i.e. gravel.

Sand used for backfill shall be natural sand( free from cinders, ashes, slag, refuse, organic materials, lumps of frozen material , boulders, rocks or stones) graded from fine to coarse. The total weight of loam and clay in it shall not exceed 10% .

In order to facilitate field and shotcreting, suitable pits shall be excavated at each circumferential field joint. They shall be paid for in the general item for excavation in trenches.

In case of any dispute arising as to the type of excavation, the Engineer-in-charge's decision as to the category and slab will be final and binding on the contractors.

3.1.3. Trenches

Trenching includes all excavation which is carried out by hand or by machine. The width of the trench shall be kept to a minimum consistent with the working space required. At the bottom between the faces, it shall be such as to provide not less than 200 mm clearance on either side of the pipe. Each case should, however, he considered on its merits, having regard to the safety ofthe trench, the method of laying and jointing the pipe and the need to avoid damage to pipe coating. The bottom of the trench shall be properly trimmed to permit even bedding of the pipeline. For pipes larger than 1200 mm diameter in earth and morum the curvature of the bottom of the trench should match the curvature of the pipe as far as possible, subtending an angle of about 1200 at the centre of the pipe, as shown in Fig. 1 A of IS 5822 : 1994. Where rock or boulders are encountered, the trench shall be trimmed to a depth of at least 100 mm below the level at which the bottom of the barrel of the pipe is to be laid and filled to a like depth with lean cement concrete or with non-compressible material like sand of adequate depth to give the curved seating, as shown in Fig. 1B and Fig. 1C of IS 5822 : 1994.

When welding is to be carried out with the pipe in the trench, additional excavation of not more than 600 mm in depth and 900 mm in length should be provided all round the pipe at the position of the joints for facilities of welding.

Trenches cross section have since been enclosed. The payment of excavation shall be made on quantity basis as per the actual dimension of the trench excavated subject to the condition and the quantity shall be limited as per the trench cross section given in the drawing.

All trench excavation and other works carried out within the limits of any Highway or roads shall be completed as rapidly as possible and not more than half of the width of the carriage way or required width of trench plus the width required for stacking of excavated materials whichever is minimum shall be obstructed at one time. Road drains shall be kept free from obstruction. In any event , the contractor shall take special precaution which shall include the continuous support of the sides of excavation from the time when excavation is begun until the refilling of the trench is placed, to ensure that there is no disturbance of the adjacent road or road foundation.

Where excavated material has temporarily been deposited on a grass margin or road pavement, the margin or road pavement shall on completion of refilling be restored entirely to its original level. Cutting of roads shall be started only after obtaining the permission of the department.

3.2. Setting Out The CONTRACTOR shall be entirely responsible for accurately setting out the WORKS. The levels shall be relative to the Survey of India Datum or any alternative approved datum, and taken to the required accuracy. Before commencing any work the CONTRACTOR shall give such notice to the ENGINEER-IN-CHARGE to enable the ENGINEER-IN-CHARGE to check

the setting out, and in any event not less than 48 hours notice. No approval either given or implied by the ENGINEER-IN-CHARGE shall relieve the CONTRACTOR of his obligations in connection with the setting out.

The CONTRACTOR shall set out the WORKS in accordance with the drawings or as otherwise instructed by the ENGINEER-IN-CHARGE. Should the CONTRACTOR wish to alter the line, level or any other part of the WORKS, the prior written approval of the ENGINEER-IN-CHARGE must be obtained.

3.3. Control of Groundwater The CONTRACTOR shall include in his excavation rates all necessary provisions for removing all water from excavations if encountered, and shall provide all plant, labour and all other items and machinery necessary to maintain all excavations and trenches dry during construction work.

3.4. Existing Services The CONTRACTOR shall give notice to the ENGINEER-IN-CHARGE at least two (2) weeks in advance advising that he intends to start with work on any site, and shall similarly advise all the concerned Departments so as to obtain all available records of existing services.

Before the CONTRACTOR interferes with roads, pavements or services, he shall obtain prior written approval to proceed from the ENGINEER-IN-CHARGE and the Department/Authority concerned.

3.5. Support of Excavation and Adjacent Property The CONTRACTOR shall keep all excavations stable at all times during construction of the pipeline.

When excavating in unstable soils or where the excavations are necessarily deep, the CONTRACTOR shall submit to the ENGINEER-IN-CHARGE his detailed proposals for supporting the excavations at the site at least seven days prior to commencement of any excavation work. His proposal shall take into account the nature of the ground to be excavated, the water table level at the site and the closeness of adjacent buildings and roads.

If, in the opinion of the ENGINEER-IN-CHARGE the support proposed by the CONTRACTOR is insufficient, then the ENGINEER-IN-CHARGE will order the provision of stronger or alternative support for the excavations than that proposed by the CONTRACTOR. In this event the CONTRACTOR shall adopt the same at no extra cost to the Client.

The CONTRACTOR shall not remove any temporary works supporting the excavation until in the opinion of the ENGINEER-IN-CHARGE, the permanent work is sufficiently advanced to permit such removal. This shall then be executed under the personal supervision of a competent foreman.

3.6. OTHER ASPECTS OF WORK COVERED UNDER EXCAVATION

3.6.1. Surplus Excavated Materials

Excavated material which is not required for use in the works shall be disposed off by the contractor to a suitable place.

3.6.2.Shoring and strutting

The contractor shall suitably design polling boards, waling and struts to meet different soil conditions that might be encountered in excavating trenches/pits. The horizontal and vertical spacing of struts shall be such that not only the sides of trenches shall be prevented from collapse but also easy lowering of pipe in trenches shall be ensured without creating undue obstructions for the excavation of the work. Any inconvenience and/or delay that might be caused in lowering pipes in trenches as a result of adopting improper spacing of struts by contractor shall be his sole responsibility. No part of shoring shall at any time be removed by contractor without obtaining permission from Engineer-in-charge. While taking out shoring planks the hollows of any form must simultaneously be filled in with soft earth well rammed with rammers and with water.

Engineer-in-charge may order portions of shoring to be left in the trenches/pits at such places, where it is found absolutely necessary to do so as to avoid any damage which may be caused to buildings, cables, gas-mains, water mains, sewers etc. in close proximity of the excavation, by pulling out the shoring from the excavations. Contractor shall not claim, on any reason, whatsoever for the shoring which may have been left in.Where the subsoil conditions are expected to be of a soft and unstable character in trench/pit excavation the normal method of timbering may prove insufficient to avoid subsidence of the adjoining road surfaces and other services. In such circumstances contractor will be required to use steel trench sheeting or sheet piling adequately supported by timber struts, waling etc., as per the instructions, manner and method directed by Engineer. Contractor shall supply, pitch, drive and subsequently remove trench sheeting or piling in accordance with other items of the specification.

3.6.3.Dewatering of Trenches

The contractor shall provide the required pumps, engines and machinery to keep the trenches, for the excavation and for pipe laying etc., clear of water, whether sub-soil water, storm water or leakage from tanks, wells, drains, sewers or pipes or due to any other source of reason so that there may be no accumulation of such water. No setting out shall be done, no masonry laid, no concrete deposited, no joints made, and no measurements taken in water. The pumping shall be continued during and after execution of any portion of the work and repeated so often as the Engineer may consider necessary. The pumps used shall be of adequate capacity and if at any time, the Engineer thinks that the pumps brought by the contractors are inadequate, the contractor shall bring on site and operate more pumps of the required capacity. If, however, the contractors fail to do so, the Engineer may make arrangements to provide and work and adequate pumps at the cost of the contractor.

The contractor shall take every precaution to discharge the water so pumped into the nearest drain in such a way that it does not spread on the road surface under traffic or cause any nuisance. If this is not possible and the road surface under traffic has to be crossed, the contractors shall restrict the flow to a suitable size pipe laid under and across the road. The pipe shall be immediately removed on completion of the works. No extra payment shall be made for making any such arrangement.

3.6.4.Fencing, Watching, Lighting

The posts of the fencing shall be of timber, securely fixed in the ground not more than 2.5 m. apart. They shall not be less than 10 cm. in dia, or not less than 1.25 m. above the surface of

ground. There shall be two rails, one near the top of the posts and the other about 0.5 m. above the ground and each shall be of 5 cm. to 10 cm. in dia. and sufficiently long to run from post to post to which they shall be bound with strong ropes. The method, of projecting rails beyond the posts and tying together where they meet will not be allowed on any account. All along the edges of the excavated trenches, a bund of earth about one metre high shall be formed where so required by the Engineer for further protection. Proper provision shall be made for lighting at night and watchmen shall be kept to see that this is properly done and maintained. "In addition to the normal lighting arrangements, the contractors shall provide whenever such work is in progress, battery operated blinking light (6 volts) in the beginning and end of a trench with a view to provide suitable indication to the vehicular traffic. The contractor shall also provide and display special boards printed with fluorescent paints indicating the progress of the work along the road. Further, in all such cases the work may be carried out departmentally at the risk and cost of the contractor. The contractor shall be held responsible for payment of all claims for compensation as a result of accident or injury to any person or property due to improper fencing, inadequate lighting or non-provision of red flags.

The contractors shall at their own cost provide all notice boards before opening of roads as directed by the Engineer.

Arrangements shall be made by the contractors to direct traffic whenever work in through fare is in progress.

No separate payment shall be paid for this item of work.

3.6.5.ExplosivesThe contractors shall make themselves familiar with the local regulations governing the excavation, quarry operation, blasting etc. and the work shall be carried out in strict accordance with local rules and regulations so far as they apply to this work.

Blasting shall not be done without the previous consent of the Engineer and shall be restricted to the hours which he may prescribe. If, in the opinion of the Engineer, blasting is likely to be dangerous to persons or adjacent structures, the rock shall be excavated by other means.

The contractor shall keep the Engineer fully informed at all times when blasting is proposed to be carried out of any details the Engineer may require concerning strength of charges and their position.

Only experienced and competent blasting operators possessing licences from the competent authority shall be employed on blasting work. In carrying out rock blasting, the contractor shall take all necessary precautions by the use of weighted down screens and other means for the protection of life and property and shall strictly comply with all rules and regulations that may be laid down by the competent Police Authority, Inspector of Explosives, Govt. of Telangana or by any other legally constituted authority having jurisdiction relative to handling, storing and use of explosives.

Audible and visible warnings (such as the waving of red danger flags and the beating of gongs) shall be given for atleast five minutes before blasting is due to begin. The contractor's foreman or other responsible person shall inspect the whole of the blasting area during the warning period to ensure that no one remains within or is likely to enter the danger area. All operators except those responsible for detonating shall be carried to a safe distance which in any case shall not be less than 200 metres.

All fuses must be cut to the lengths required before being inserted into the holes.

The number of charges to be fired and the actual number of shots heard, must be compared, and the person responsible must satisfy himself by examination that all the charges have exploded, before work people are permitted to approach the scene. The withdrawal of any charge, which has not exploded can under no circumstances, be permitted. The tamping and charge shall be flooded with water, and the hole marked in a distinguishing manner. Another hole shall be jumped at a distance of about 45 Cms., from the old hole and fired in the usual way. The results shall be carefully examined by the person in charge of the blasting, and operation continued, until the original charge is exploded.For "Storage of Explosives", the contractors shall obtain the previous permission of the competent Police Authority for the location of magazine site, manner and method of storing explosives near the sites of works. All handling of explosives, including storage, transport, etc., shall be carried out under the rules approved by the Explosives Department of the Government.In order to ensure the safety of surrounding property and persons, no charge shall be used which is larger than necessary. Rock excavation continuous to any structure shall be carried on in such a manner as not to cause damage to it.

3.6.6.Supporting of and Repairs to the Damaged Public Utilities

Utilities such as water pipes, drains, sewers, cables etc. which happen to foul the alignment, shall be temporarily supported throughout the work by the contractor at his cost to the satisfaction of the Engineer. In this connection, the contractors have to contact the concerned departments and take all precautions that are considered necessary by them. On completion of the pipe laying operation and before refilling the trenches, some of the utility may have to be supported permanently by providing either masonry or concrete as directed. If during the execution of work any public utilities or house connections are damaged, the same shall be repaired either by the contract or thorough the concerned department at the risk and cost of the contractors.

13. TRANSPORT OF MS PIPES, SPECIALS, VALVES, DI PIPES, DI FITTINGS ETC.

The M.S. pipes and Specials, valves, base plates, manhole covers, appurtenances, bolts and nuts, distance pieces, flanges, saddles, collars, bye-pass arrangements etc. shall be transported by the contractors. Inlining and outcoating of M.S. pipes and specials shall also be done at the factory before conveying from factory to laying site.

1. HANDLING OF PIPES, APPURTENANCES, VALVES AND SPECIALS

It is essential to avoid damage to the pipes, fittings and specials, etc. or their coatings at all stages during handling. The pipes and specials shall be handled in such a manner as not do distort their circularity or cause any damage to their inlining and outcoating. Pipes shall not be thrown down from the trucks nor shall they be dragged or rolled along hard surfaces. Slings of canvas or equally non-abrasive materials of suitable width of special attachment shaped to fit the pipes ends shall be used to lift and lower pipes so as to eliminate the risk of damage to the coating.

Great care shall be taken in handling the pipe right from the first operation until they are laid and jointed. the contractors shall be responsible for any loss or damage to the pipes, specials, or their coatings. No defective or damaged pipe or specials shall be allowed to be used in the work

without rectification to the satisfaction of the Engineer. Any damage to the pipes and specials shall be repaired by the contractor at his cost to the satisfaction of the Engineer.

2. GENERAL SEQUENCE OF OPERATIONS FOR LAYING ABOVE GROUND PIPELINE

Before commencing the work of pipe laying, the contractor shall study the Longitudinal Section of the pipeline for the section concerned and shall also study the details of the type of pedestals to be provided.

The contractor shall submit the detailed working drawings showing the positions of the pedestals to be cast in the section, the formation of which is ready for laying the pipeline, The detailed working drawings shall be approved by the Engineer-in-Charge before proceeding for the construction. Pipe laying shall generally start from the fixity points on either side, the expansion joint being provided last. Fixity points are at all anchor blocks and pedestals.

Pedestals shall be constructed before commencing the pipe laying work in any section.

3. LAYING UNDERGROUND PIPE LINE

3.1. Steel Pipes

Laying of welded steel pipes conform to I.S. 5822-1994.

The steel pipes shall be lowered into the trench preferably by cranes. Any other method of handling shall be got approved by the Engineer. It shall also be necessary to see that the outer coating of pipe is not damaged in any way during lowering and assembling. After the pipe is lowered in the trench, it shall be laid in correct line and level by the use of the levelling instruments, sight rails, theodolite etc. Care shall be taken to see "that the longitudinal joints of two consecutive pipes at each circumferential joint are staggered by 90 deg. while assembling the pipes , the ends shall have to be" brought close enough to leave an uniform gap not exceeding 3mm. If necessary, a required cut may be taken to ensure a close fit of the pipe faces. For this purpose, experienced cutters who can take uniform and straight cuts, shall only be permitted to cut the faces of the pipe. No extra payment shall be made for such required cutting. There shall be no lateral displacement between the pipe faces to be jointed. If necessary, spiders from inside and tightening rings from outside shall be used to bring the two ends in perfect contact and alignment. It may also be necessary to use jacks for this purpose. In no case shall hammering or longitudinal skidding be permitted. When the pipe is properly assembled and checked for correct line and level, it shall be firmly supported on wooden beams and wedges and tack welded. Some portion of the trench may be refilled at this stage so as to prevent the pipe line from losing its alignment.

The tack welded circumferential joints shall then be welded fully. Only experienced welders who shall be tested from time to time shall be permitted to carry out the welding work. No apprentice or helper shall be allowed to do any welding whatsoever. If any unauthorized person if found doing welding work, he shall be removed from the work and the work carried out by him shall be re-done after gouging out the same. The welder shall produce a certificate of having adequate training and/or experience from an Institute or Firm, where he has been trained or gathered experience on similar jobs.

Baling or pumping out of water from trench including shoring, strutting and removing slush while laying, jointing and testing shall be done by the contractor. The contractor shall take precaution from caving, sliding, under pinning, flotation at his expense.

4. Precautions Against Flotation

When pipeline laid underground or above ground in a long narrow cutting gets submerged in water collected in the trench or cutting , it is subjected to an uplift pressure due to buoyancy and is likely to float , if completely or partly empty. In the design of pipelines, provision is made to safeguard against flotation by providing sufficient overburden or by providing sufficient dead weight by means of anchor blocks.In the case of works extending over one or more monsoon seasons, however special care and precautions are necessary during the progress of work on this account. The work of providing anchor blocks and refilling the trenches to the required level and compacting the same etc. shall always be done as soon as the pipeline has been laid.

The contractor shall see that water will not be allowed to accumulate in open trenches, where work is in an incomplete stage, precautionary work such as blank-flanging the open ends of the pipeline and filling the pipeline with water etc., shall be taken as directed by the Engineer. Such works shall be to the contractor's account and no separate payment will be made for the same. A minimum of 1.3 metres over burden shall be maintained at all times. Where this overburden is not available, anchor blocks have to be provided as shown in the L.S. Plans of Specification Drawing.

Protection of pipeline against flotation during the contract period shall be the responsibility of the contractor. Should any section of the pipe line float due to their negligence etc., the entire cost of laying it again to the correct line and level shall be to his account.

5. DIMENSIONS OF M.S. SPECIALS

Specials such as Y-pieces, Bends (single or composite), Tees, Tapers, etc., shall be in accordance with IS: 7322-1985. Smaller branches, angle piece bends etc. may be fabricated at site, care being taken to ensure that the fabricated fittings have at least the same strength as the pipe line to which they are jointed. If any extra single bends have to be modified by cutting their ends to suit the variation in deflection, the same shall be done by the contractors as may be directed by the Engineer. For such cutting of pipes and specials, the contractors shall not be paid for separately. The ends of M.S. pipes and specials jointing the MS Pipes shall be provided with machine ends to suit the MS Pipes.

The inlining and outcoating of specials shall conform to I.S. 9012-1978 and relevant specifications for guniting. The cement mortar proportion for lining shall be 1:2 proportion by volume and for outcoating, the cement mortar proportion shall be 1:3.

6. PREPARING STEEL PIPE FACES FOR WELDING

Before aligning, assembling and welding, the pipe faces shall be cleaned by scrapping, with wire brushes or any other method approved by the Engineer.

7. WELDING JOINTS

As regards the welding work, the following points shall be borne in mind by the Contractors.

7.1. Electrodes

The Contractors shall use standard electrodes depending on the thickness of plate and the type of joint. They shall also use standard current and arc voltage required for the machine in use as per manufacturer's directions. Welding Electrodes shall conform to I.S. 814-1991. "Specifications for covered electrodes for metal arc welding of mild steel" (second or latest revision) Indian made or equivalent foreign make electrodes of the required quality approved by the Engineer, shall be used wherever possible.

7.2. Welded Joints (other than for closing lengths)

Shall be of the butt welded type with an internal circumferential weld. However, pipes 900 mm. and below in dia. shall be jointed with external welds and pipes larger in size will be circumferentially welded both internally and externally. All fillet welds shall have a throat thickness not less than 0.7 times the thickness of the pipe to be welded.

All parts to be welded shall have loose scale, slag, rust, paint and other foreign matter removed by means of a wire brush and shall be left clean and dry. All scale and slag shall be removed from each weld when it is completed.

Welding of straps shall be done as specified in PL 23.

7.3. Gousing

M.S. Pipes larger in size i.e. more than 900 mm. dia. will have to be welded internally and externally. At the time of internal welding, a `V' cut is made from inside of the pipes and after completing the internal welding with required number of runs, the external welding (sealing run) is incumbent. Before starting the external welding (sealing run) the internally welded material in the joint will have to be cleaned by Gousing with Gas flame. Gousing shall be done before starting the external welding (sealing run) and the rate of welding shall include the cost of gousing also. Gousing will also be carried out before rectifying the defective welding wherever necessary and as directed by the Engineer.

7.4. Procedure

The welding of pipes in the field shall comply with I.S. 816-1969 (code of practice for use of metal arc welding for general construction in mild steel).

The openings in the laid pipeline in the form of manholes made at suitable distances, for access into the pipeline for the work of cleaning, painting and repairs to the welds etc. shall be closed by welding a new patch on the opening.

Such manholes should, as far as possible, be provided at the sides of pipelines; and cutting at the crown of the pipe should be avoided. The following procedure should be strictly adopted while plugging the manholes by patch plating:-

(1) The manholes shall be plugged by providing a patch plate cut from a separate stack of pipe of the same dia. the old plate cut from the pipeline shall not be used for this purpose.

(2) The edges of the new patch plate shall be properly shaped and the same shall be inserted in the opening by keeping gap of 3 to 4 mm. and tacked.

(3) The welding of the patch plate should be done in segments with proper sequence conforming to I.S.S. 623 (12.3).

7.5. Testing of Welded Joints

(i) The welded joints shall be tested in accordance with procedure laid down in I.S.S. No. 3600 of 1966: "Code of Procedure for testing of fusion welded joints and weld metals in steel". One test specimen taken from at least one field joint out of any ten shall be subjected to test.

(ii) The test pieces shall be taken out from the positions pointed out by the Engineer without any delay. They shall be machined immediately and tested in week's time.

(iii) The shape of the test pieces removed from the pipes shall be such that it will give a specimen of the required dimensions and at the same time leave a hole in the pipe with rounded corners. This hole shall be patched up by inserting and welding suitable sized plates. Great care shall be taken in preparing these plates so as to get a good butt weld.

(iv) After the jointing is completed, all protruding portions shall be chipped off and ground smooth and the inlining and outcoating shall be done by guniting.

(v) The entire cost of the test including taking out test samples, machining the test pieces, transport to and from the laboratory and testing them in a laboratory, the cost of patching up the test piece hole in the pipe, payment of all testing fees, cleaning and painting the same, shall be borne by Contractor. The tests shall be carried out in some Government or semi-Government Institute approved by the Engineer. This shall be arranged by the Engineer entirely at the Contractor's cost.

(vi) The following tests shall be made:-

(a) Tensile:

The test specimen taken perpendicularly across the weld shall be shaped in accordance with I.S.S. No. 223 of 1950. The specimen shall be taken from the end of the pipe or at any field joint in the pipe as directed by the Engineer and shall be cut with the weld approximately in the middle of the specimen. The tension test specimen shall be machined. The protruding welded portion from both inside and outside shall be removed by machining or grinding before the specimen is tested.

At least one field joint out of every ten shall be subjected to test by taking out a specimen. If a test specimen shows defective machining or develops flaws not associated with welding, it may be discarded and another specimen substituted.

The welded joint shall show a strength not less than the minimum tensile strength specified for the plate. (Please refer to I.S.2062 of 1992 or latest revision). "Specifications for structural steel (Standard Quality)".

(b) Bend Tests:

The bend test specimen shall be prepared in the same way as that for tensile test and tested in the presence of the Engineer. The specimen shall stand being bent cold

through 180 degrees around a pin the diameter of which is equal to 4.5 times of thickness of the plate, without developing cracks. In making the bend test, the side of the specimen representing the inside of the pipe shall be placed next to the pin.

(c) Tre-panned Plugs:

Tre-panned Plugs shall be taken out from any welded portion by the Engineer. The plugs taken out shall not show, on examination, any defects in welding such as inclusion of slag, blow holes, cavities etc. the plug shall be 12 mm. in dia. and shall be taken out by means of a suitable hole-saw operated electrically.

The holes shall be either filled back by inserting a steel stud and welding all round or by threading the hole and providing a suitable G.I. Plug.

The tre-panned plugs shall be taken out only if considered necessary by the Engineer.

(d) Re-Test:

If the results of the tensile or bend test of any lot do not conform to the requirements specified, retests of two additional specimens from the same section shall be made, each shall conform to the required specifications. In case of failure of one or both, extensive gousing (scopping out) and repairing shall be carried out as directed by the Engineer before the lot can be accepted.

(vii) The welder / operator shall be held responsible for any failure of the joint. Since factors such as current, and voltage, quality of electrodes etc. are already determined and controlled, the failure is due to carelessness and negligence of the welder. For the first failure the welder operator shall be warned and for the second failure, he shall be removed from the work and replaced by another suitable operator. The joints or a portion thereof shall be gouged and repaired to the satisfaction of the Engineer. In order to maintain a good standard in welding, all welders shall be tested before they are entrusted with any job. They shall be periodically tested at intervals of every six months.

(viii) 10% of field welded joints shall be subjected to Radiographic Tests as per I.S. 4853-1983. The contractor shall mention the details of tests as per the specification regarding Class-`A', Class-`B' tests, type of IQI recommended technique for making radiographs, type of industrial X-ray films, intensifying screen, system of marking etc.

(ix) A complete record shall be maintained by the contractors showing the names of welders and operators working on each individual joint. The work shall preferably be carried out by a pair of welders so that by observing proper sequence, distortion can be avoided. A joint entrusted to a particular individual or pair shall be as far as possible completed by them in all respects, including the sealing run. No helper or other unauthorized unqualified person shall be permitted to do any welding work whatsoever. In case of any infringement, the person concerned shall be punished as directed by the Engineer.

7.6. Internal lining of Joints

After welding of joint and testing of welded joints as per technical specifications of this document completed in all respects the internal lining of the pipeline shall be completed at every joint, using cement mortar 1:2. The Contractor shall ensure that the surface of the pipe is cleaned and

wire brushed to expose a surface free of all foreign matter. A steel wire fabric 50 mm X 50 mm X 3mm conforming to I.S.S. 1566 shall be fixed to the interior of the pipe joint. He shall then apply approved bonding agent to ensure adherence of the lining material.

The Contractor shall employ only skilled workmen to complete the internal lining at joints which shall be finished so thickness and surface finish equal to that specified for the pipes.No internal lining shall be applied to any welded joint until the welded joint has been successfully tested as specified above. However internal lining of joints has to be done before taking up the hydraulic tests.

7.7. Outcoating with guniting of field welded joints

The external face of field welded joint shall be completed at every welded joint using cement mortar 1:3 by volume. The contractor shall ensure that the surface of the pipe is cleaned and wire brushed to expose a surface free of all foreign matter. The fabric as used for guniting for pipes in factory has to be provided to the external surface of the field welded joint. The field welded joint shall not be made good using outcoating until the welded joint has been successfully tested as above. Only skilled workmen shall complete the external protection which must be equal in quality to that of the pipes.

8. GAS CUTTING

In the course of the work, the contractors may be called upon to cut steel pipes, specials, etc. on site. Gas cutting shall be adopted for preparing on site, distance pieces, straps etc. cutting out holes in the pipeline laid for manholes, scour valves, air valves and other appurtenances, holes required for blast cleaning operation, cutting of pipe faces to form kinks or bends, holes required for bye pass arrangement.The rate for gas cutting shall include chamfering for forming `V' or square cut, cost of aligning, holding in position member etc., and shall cover thickness upto 25 mm.

After cutting, the edges shall be made smooth and even by using electrical or pneumatic grinder so as to remove all inequalities. Care shall be taken to see that the shape of the material cut is not defaced in any way at the time of cutting. The ends of the pipe shall have bevel edge or `V' edge to facilitate hand welding. As field welding is to be carried out from inside in the case of pipes of diameter 900 mm. and above, the bevel shall be from inside. For pipes of smaller diameter, as field welding has to be done from outside only, the edges of pipe cut shall have bevels to suit the above.

9. FLANGES

Flanges shall be provided at the end of pipes or specials where sluice valves, butterfly valves, blank flanges, tapers etc. have to be introduced. The contractors shall assemble the flanges in exact position of the sluice valve, if necessary, so as to get the desired position of the sluice valves etc. either vertical or horizontal and shall then fully weld the flanges from both sides in such a way that no part of welding protrudes beyond the face of the flanges. In case welding protrudes beyond the flanges and if the Engineer orders that such protrusions be removed, the contractors shall either file or chip them off. If required, and when ordered by the Engineer, the contractor shall provide gusset stiffeners, welded as directed on site.

10. BLANK FLANGES

Blank flanges shall be provided at all ends left unattended for the temporary closure of work, and also for commissioning a section of the pipeline or for testing the pipeline laid. For temporary closures, non pressure blank flanges consisting of mild steel plates, tack welded at the pipe ends may be used. For pipes subjected to pressures, the blank flanges or Domes suitably designed as per Engineer's requirements shall be provided. All the above arrangements shall be done at contractor's expense.

11. STIFFENER RINGS

The stiffener rings shall have to be provided wherever directed by the Engineer-in-Charge. The contractor shall weld the same to the pipes with one circumferential run on each side. The pieces of the rings shall also be welded to each other as directed.

If the stiffener rings are fixed in position after the pipes are lowered into the trench, the welding and guniting shall be carried out in the same welding pit excavated for the field joints and, therefore, no extra payment will be made for the excavation of the pit for welding and guniting.

12. STRAPS

Wherever pipe laying work is done from two faces and/or has to be done in broken stretches due to any difficulty met with at site, the final connection has to be made by introducing straps to cover gaps upto 30 cms. length. Straps shall also be provided as per the procedure of fixing Expansion joint. Such straps shall be fabricated in the field by cutting pipes, slitting them longitudinally and slipping them over the ends to be connected in the form of a collar. The collar shall be in two halves and shall have its inside diameter equal to the outside diameter of the pipe to be connected. A minimum lap of 8 cm. on either ends of the pipe shall be kept and fillet welds shall be run both internally and externally for circumferential joint. In case of pipes 900 mm. dia. and below, internal fillet weld may not be provided if so permitted by the Engineer. The longitudinal joints of the collar shall be butt-welded. All fillet welds shall have a throat thickness of not less than 0.7 times the width of weldings.

13. APPURTENANCES

Appurtenances such as sluice valves, air valves, scour valves, control valves, manholes shall be provided by the contractor. The work of fixing appurtenances, i.e. sluice valves, butterfly valves, air valves, scour valves, etc. shall be carried out carefully so as not to damage them during handling, erection and fixing. The entire assembly of the appurtenances upto the steel flanges which are to receive the castings shall be paid for separately and the rate under this item shall be exclusively for supplying, fixing including the cost of jointing materials such as rubber, packing, bolts and nuts etc., the castings in proper position and alignment.

Throughout erection, the valves shall be supported properly on wooden sleepers, etc. and shall be converted immediately thereafter as directed. Before the valves are actually fixed, they shall be cleaned and greased and it should be seen that all the parts are in perfect working condition. In the case of air valves, the contractors, shall take special care of the dexine joints and the ebonite and/or vulcanite balls until they are fixed in position. They shall be kept immersed in water in suitable containers.

The rate of supplying and fixing of appurtenances shall include all relevant items including the cost of transport, loading and unloading, etc.

14. CONNECTING THE NEWLY LAID MAIN WITH EXISTING MAINS

The proposed main shall be connected to the mains as shown on the drawing and/or as directed by the Engineer.

All work for external connection including all outside welding at the above mentioned places and anchor blocks shall be carried out and provided by the contractors including the work of making actual connections by cutting and existing pipes at the faces of the connections. The programme of isolation and dewatering of live main to be cross-connected shall be chalked out in consultation with Engineer and taking into consideration the convenience of water supply; co-ordination with other repairs, maintenance or new works to be carried out in that section etc. The contractors shall carry out the cross-connection work according to the programme thus drawn up.

15. APPLICATION OF ZINC RICH EPOXY PRIMER

The mix of zinc rich epoxy primer shall be prepared 15 minutes before applying on the works site.

One coat of Zinc Rich Epoxy Primer shall be applied by spray, right upto the edge of the pipe giving a film thickness of approximately 1 mil.

No thinner should be added to the ready mixed paints without the previous approval of the Engineer. Though the priming coats become dust free & dry in 10-15 minutes, finishing shall only be applied after allowing the film to cure at least for 48 hours.

16. TRANSPORTING AND HANDLING COATED PIPES, SPECIALS, APPURTENANCES_ETC.

Pipes, specials, valves etc. shall be handled at all times with equipment such as stout wide belt slings and wide padded skids designed to prevent damage to the coating. Bare cables, chains, hooks, metal bars or narrow skids shall not be permitted to come in contact with the coating.

In truck shipments, the pipe shall be supported in wide cradles of suitably padded timbers hollowed out on the supporting surface to fit the curvature of pipe, and all chains, cables, or other equipment used for fastening the load shall be carefully padded. For smaller diameter pipes, sand or saw-dust filled bags may be used instead of hollowed out timbers.

The Engineer shall inspect the pipe and pipe protection on trucks at destination, and if the pipe protection is found damaged, the same shall be repaired to the satisfaction of the Engineer by the contractor at his cost.

17. HANDLING COATED PIPE IN FIELD OR AT TRENCH

The laying of pipes shall generally conform to I.S. 5822-1994 and IS: 12288-1987 for MS pipes and DI pipes respectively.Pipe shall be stored along the trench side suitably supported off the ground to avoid damage to the coating.

Pipe shall be hoisted from the trench side to the trench by means of wide belt slings. Chains, cables tongs or other equipment likely to cause damage to the enamel coating will not be permitted, nor do the dragging or skidding of the pipe. The contractor shall allow inspection of

the coating on the underside of the pipe while it is suspended from the slings. Any damage shall be repaired before the pipe is lowered into the trench.

At all times during construction of the pipeline, the contractor shall use every precaution to prevent damage to protective coating on the pipe. No metal tools or heavy objects shall be permitted to come into contact unnecessarily with the finished coating. Workmen will be permitted to work upon the coating only when necessary in which case they shall wear shoes with rubber or composition soles and heels. This rule shall apply to all surfaces. Any damage to the pipe or protective coating from any cause during the installation of the pipeline shall be repaired, as directed, and at the expense of the contractor.

18. REFILLING OF TRENCHES

(a) On completion of the pipe laying operations in any section, for a length of about 100 metres and while further work is still in progress, refilling of trenches shall be started by the contractor with a view to restrict the length of open trenches. Pipe laying shall follow closely upon the progress of Trench Excavation and the contractor shall not permit unreasonable excessive lengths of trench excavation to remain open while awaiting testing of the pipeline. If the Engineer considers that the contractor is not complying with any of the foregoing requirements, he may prohibit further trench excavation until he is satisfied with the progress of laying and testing of pipe and refilling of trenches. Only soft earth and gravel of good quality free from stones greater than 50 mm. in size free from boulders, roots, vegetable matter etc. shall be utilized after the lumps are broken. The excavated material nearest to the trench shall be used first. If sufficient quantity of excavated gravel is not available the trench shall be filled by borrowed gravel or material upto 30 Cms. above top of pipe. Care shall be taken when back filling, not to injure or disturb the pipe or joints of the outcoating. Filling shall be carried out simultaneously on both the sides of the pipes so that unequal pressure does not occur. Walking or working on the completed pipeline shall not be permitted unless the trench has been filled to a height of at least 30 cm over the top of the pipe expect as may be necessary for tamping etc. during back filling work. Filling in shall be done in layers not exceeding 10 cm. in thickness accompanied by adequate watering, ramming etc. so as to obtain good compaction up to 30cm above the top of the pipe. Above this level , excavated earth free from boulders shall be placed in layers of 160mm, watered and compacted by tamping.. Water contents of the soil shall be as near as the optimum moisture content as possible. The trench shall be refilled so as to build up to the original ground level, keeping due allowance for subsequent settlement likely to take place.

The Engineer-in-charge, all times, have powers to decide which portion of the excavated material that shall be used for filling and in which portion of site and in what manner it shall be so used.

The surplus and useful material shall be removed by the contractor to any selected site within a specified period. The contractor is responsible for selection of the site for disposal of surplus earth. Separate payment will be made for such removal etc. of the surplus excavated material. However the cost of the site selected for dumping the surplus earth or any other incidental charges other than that required for removal of the surplus excavated material will not be paid. If the contractors fail to remove the earth from site within seven days after the period specified in a written notice, the Engineer-in-charge may arrange to carry out such work at the contractor's risk and cost or may impose such fine for such omission as he may deem it.

(b) Filling in incomplete Works

If the work for which an excavation is made, is not completed before the day fixed by the Engineer-in-charge for filling in any excavation on account of any special occasion or ceremony or important festivals such as Diwali, Moharrum, etc. the contractor shall refill such excavation and consolidate the filling at his own expense not withstanding the non-completion of the work as aforesaid. In no such case shall the contractor have any claim for payment of such excavation, in refilling or consolidation nor for any such incomplete work, but on the other hand, the contractor shall bear the cost of road repairs in respect of such excavation at such time, together with the cost of such procedure as may be adopted by the Engineer.

(c) Subsidence in filling

Should any subsidence take place either in the filling of the trenches or near about it during the defect liability period, the contractor shall make good the same at their own cost, or the Engineer, may without notice to the contractor, make good the same in any way and with any material that he may think proper, at the expense of the contractor. The Engineer may also, employ persons for making good the same, and the expenses on this account shall be charged to the contractor.

(d) Bedding for Pipes

Class-S bedding and surround shall be provided with granular material i.e. gravel as indicated in the drawing.

19. INTERNAL CLEANING OF PIPELINEWhen a section of pipeline has been laid and all the work inside it, has been completed to the satisfaction of the Engineer, its internal surface shall be cleared of all dirt, debris, dust or other deposit.Cleaning shall be done to the satisfaction of the Engineer. The section of the pipeline once cleaned to the satisfaction of the Engineer shall not be entered into for any purpose later. Sufficient precaution shall be taken to prevent the ingress of any dirt, debris etc. just inside the section. Failing this, the section shall be cleaned again at the discretion of the Engineer.No separate payment will be made for the work of cleaning. The percentage rates/item rates quoted for laying the pipes etc. shall include the cost thereof.

In the case of above-ground pipeline, the length of the section to be taken up for cleaning shall be decided in consultation with the Engineer from the point of view of ventilation etc.

In case of buried pipeline a section shall be taken up for cleaning after the work of back filling around and over the pipeline is completed and the spiders, etc. have been removed from inside.

During the pipe laying operations in the adjoining sections, the contractor shall take all precautions to prevent ingress of water, muck, debris, dirt, dust, etc. in the cleaned section, failing which the section shall be cleaned again at the discretion of the Engineer. Where deemed necessary by the Engineer, suitable closures shall be provided at the open end or the ends of the cleaned sections.

At the end of a day's work, closure shall invariably be provided at all the open ends to protect the pipeline from ingress of sub-soil water, mud, muck, etc.

20. FIELD HYDRO STATIC TESTING OF MS PIPELINE INCLUDING MS PIPES AND SPECIALS and DI PIPELINE

MS PIPELINE

After the work of laying of pipeline is completed and before putting into commission, the MS Pipelines shall be hydraulically tested in the field as per Clause 11.2 of IS:5822-1994 as and when directed by the Engineer-in-charge for a pressure specified in the Bill of Quantities for pipes manufactured with thickness MS plate specified in the Bill of Quantities as the case may be. The procedure for the test shall be as follows.

Preliminaries

For purpose of pressure testing, the pipeline shall be divided into sections as defined by the Engineer.

Each valved section of the pipeline shall be subjected to a hydraulic test in full length or in part as may be found necessary. For this test, the pipe shall be slowly filled with clean water as directed and all air shall be expelled from the pipeline through hydrants, air valves and blow offs fixed on the pipeline. Once the pipeline is full the pressure in the line should then be raised and built up and maintained by means of suitable approved pumps, to the specified test pressure based on the elevation of the lowest point on the line or section under test. The test pressure shall be maintained for one hour. If a drop in pressure occurs, the quantity of water added in order to re-establish the pressure should be carefully measured and this should not exceed 0.1 litre per m of pipe dia per Km of pipeline per day for each 30 m of head applied.

The leaking joints noticed during testing shall be repaired. The repaired joint shall be subjected to a re-test. No section shall be accepted unless it is retested satisfactorily. The contractors shall make all arrangements for all labour, pumps, pressure gauges, equipment etc. No main valves or cross connection either on the new or the existing main shall be operated by the contractor, and only the Engineer's Representative shall operate the same. The contractor shall arrange for labour required for operating the air valves, etc.

21. METHODS OF MEASUREMENTS

21.1. For manufacture, supply and delivery of pipes, measurement shall be taken for actual number of pipes multiplied by the standard length.

21.2. Specials like tees, bends, tapers, manholes shall be measured per piece/ set including or excluding valves as provided in the Bill of quantities..

21.3. Laying and jointing of pipes and specials and valves will be measured in linear metres along the centre line of the pipes actually laid jointed and tested and will be limited to the number of pipes X standard length + length of all specials and valves.

21.4. Anchor blocks, thrust blocks, pedestals and any other concrete structures shall be measured volumetrically (Cum)

21.5. For carting and recarting of earth, the quantity of earth to be taken into account shall be as per the quantity in its natural state and not loose quantity as per lorry trips.

22. PIPELINE DISINFECTION

22.1. The internal surfaces of all pipelines and pipe work including all equipment incorporated in a pipeline or pipe work through which water will pass shall be disinfected after they have been cleansed to the satisfaction of the Engineer-in-Charge.

22.2. Disinfection shall be effected by filling the pipeline with water dosed with chlorine, and shall be carried out when filling the pipeline with water for carrying out the hydraulic Test on Completion. Alternative methods may be adopted with the approval of the Engineer-in-Charge.

22.3. The concentration and method of the chlorine dosing shall be such as to make available 20 mg/l of free chlorine throughout the pipeline.

22.4. The water shall stand in the pipeline for a minimum period of 24 hours and all valves in the system shall be operated twice during this period.

22.5. Following completion of the hydraulic test and final connection at either end of the pipeline, the Contractor is to refill any empty sections with water having 20 mg/l of free chlorine and leave this water in the pipeline.

22.6. When having to dispose of any chlorinated water, the contractor shall have a method by which the chlorine can be neutralized by the use of sodium thiosulphite prior to disposal. The contractor shall obtain the Engineer-in-Charge approval for any such method of disposal.

23. CONSTRUCTION OF CLASS-S BED AND SURROUND

23.1. Class-S pipe bed and surround shall be constructed as indicated on the Drawings.

23.2. The granular material shall be evenly spread over the full width of the formation and lightly hand compacted to a level slightly higher than the level corresponding to the underside of the pipe barrel to allow for settlement of the pipe to the correct level.

23.3. Following placement and jointing of the pipe further granular material shall be placed in the trench, special care being taken to fill under the sides of the pipes to ensure full contact with the barrel of the pipe.

23.4. Trench supports shall be withdrawn gradually in accordance with the progress of the fill with the provision that such withdrawal shall not prejudice the safety of the works.

23.5. The contractor shall ensure that the material to the sides of the pipe is adequately compacted in layers having a maximum thickness of 200 mm and that the method of compaction used shall achieve not less than 95% of the maximum dry density as determined from IS: 2720: Part-7.

23.6. After each section of the pipeline has passed the hydraulic test, the holes left at exposed joints shall be backfilled and compacted to the above specification.

24. PIPELINE MARKER POSTS AND CHAMBER MARKERS

24.1. Pipeline marker posts shall be installed at 100 m intervals along the straight lengths of pipe and at all changes of horizontal alignment. Marker posts shall be of precast concrete to the dimensions shown in the Drawings. They shall be constructed of Grade 30 N/mm2 concrete with 20 mm nominal size aggregate and be reinforced with 4 No 10 mm diameter high yield steel reinforcing bars tied to give 30 mm cover to each face.

24.2. Engraved galvanized marker plates shall be installed on the cover slab of all air valve, washout and line valve chambers. The plates shall be fixed by means of 4 No. 19 mm dia expanding bolts.

25. VALVES

The specifications for all types of Valves on MS pipes shall confirm to the standards and technical specifications as specified in the Technical Specifications for Valves of Tender Document.

The valves, fittings and its accessories proposed on MS pipes shall withstand the same pressure of main line as specified in the Bill of Quantities.

26. DI SPECIALS, FITTINGS AND ITS ACCESSORIES ON MS PIPES

The specifications for all types of Valves shall confirm to the standards and technical specifications as specified in the Technical Specifications for Valves of Tender Document.

The DI Specials, fittings and its accessories proposed on MS pipes shall withstand the same pressure of main line as specified in the Bill of Quantities.

14. QUALITY CONTROL

1. IDENTIFYING DEFECTS

1.1. The Engineer-in-Charge or his authorized agents shall check the contractor’s work and notify the contractor of any defects that are found. Such checking does not affect the contractor’s responsibilities. The Engineer-in-Charge may instruct the Contractor to search for a defect and to uncover and test any pipeline, which he considers may have a defect.

1.2. If the Engineer-in-Charge instructs the Contractor to carry out a test not specified in the Specification to check whether any pipeline has a defect and the test shows that it does, the contractor has to pay for the test and any samples. If there is no defect, the test charges will be paid by the Department.

2. RESPONSIBILITY OF CONTRACTOR

2.1. The Contractor is fully responsible for all-construction defects/ manufacturing defects and quality problems of all works, materials like pipes and other accessories etc. that becomes the part of the finished work. He shall bear whatever extra expenditure occurs due to rectification works/ replacements/ all manufacturing defects, damages, rejection of material due to non-conforming to BIS Standards found during inspection of Q.C. officials. The contractor should satisfy himself before delivery of pipes, specials, valves, and any other material that they conform to relevant BIS standards and relevant tests are done successfully as per standards. The Contractor should maintain field book, material at site account register, labour engaging register, equipment at site register and site order book and kept for inspection of officers attending the site.

2.2. Both the Engineer –in – Charge and the contractor representative should sign the registers maintained at site every day.

3. INSPECTION AUTHORITY

3.1. The Engineer-in-Chief, RWS&S/ Chief Engineer, RWS&S, Hyderabad or his authorized official or agencies will inspect the pipes, specials and other manufacturing units of the contractor at any time after entering into agreement and carry out inspection before delivery of pipes, specials, valves and all other material, accessories or equipment. The manufacturer shall keep all the relevant records related to quality control and calibration certificates. If any defects are found, the inspection team may reject the pipes or other materials intended for use on the entrusted work. The Q.C. cleared materials shall only be delivered at site.

3.2. The Departments/ agencies that are fixed by the employer/ State or Central Government/ law or act for the purpose of inspection and quality checking shall have right to enter the site and check the quality of works/ materials/ machinery/ equipment etc., and the Contractor should facilitate and co-operate to carry out such inspections and quality checks.

3.3. The inspection authority shall mark a copy of the indent furnished by the agency and QC cleared certificates to the Employer.

3.4. In other cases Engineer/ Employer will order the third party inspection from the panel approved by the department.

4. CORRECTION OF DEFECTS

4.1. The Engineer-in-charge shall give notice to the Contractor of any defects before the end of the defect liability period. The defect liability period shall be extended for as long as defects remain to be corrected.

4.2. Every time notice of a defect is given, the Contractor shall correct the notified defect within the length of time specified by the Engineer.

4.3. The Contractor is to correct defects, which is noticed by him before the end of the Defects liability period. The loss or damage to the works or materials arising from Contractor’s acts or omissions during the period from start date to defects correction period shall be remedied by the contractor at his own cost.

4.4. The Engineer-in-charge is to certify that all defects have been corrected when all known defects have been corrected.

5. UNCORRECTED DEFECTSIf the contractor has not corrected a defect within the time specified in the Engineer’s notice, the Engineer will assess the cost of having the defect corrected and the contractor will pay this amount or recovered from the contractors bill/deposits. The contractor shall not have right to contest the reasonableness of the cost assessed by the Engineer-in-charge.