LAYING OF 8 INCH STEEL GAS PIPELINE BY HDD METHOD FOR CROSSING OF GURUPURA RIVER AND ASSOCIATED WORKS AT DAKSHIN KANNADA GA CGD PROJECT OF GAIL GAS LIMITED

HDD AND ASSOCIATED WORKS FOR GURUPURA RIVER CROSSING

Complete work for Fabrication, Installation & Testing of carrier pipeline of size 8" NB 6.4 mm wall thk, API 5L Gr. X52, PSL2 across Gurupura river by HDD method in all kinds of soil, including rocky strata. Detailed construction drawings shall be prepared by the contractor and duly approved by Owner/Consultant. The scope includes design, preparation of the design basis report, detailed execution philosophy, risk mitigation philosophy, and detailed engineering as per specifications, approved procedures, and other applicable drawings. The job includes execution of the complete crossing and associated works, including but not limited to the following works, in accordance with specifications, scope of work, drawings, and all provisions of the contract documents and instructions of the Owner/Consultant. Survey data such as geotechnical investigation reports and hydrological survey data, etc., are attached to the tender document. The contractor shall submit design calculations and all construction (profile) drawings along with survey data for Owner/ PMC approval. The work shall commence only after approval of the above.

"Receiving and taking-over" as defined in the specification, handling, loading, transportation and unloading of Owner supplied externally corrosion coated line pipes and other Owner supplied materials from Owner's designated place(s) of issue/ dump site(s) to Contractor's own stock-yard(s)/ Work Shop(s)/ work-site(s) including stringing of line pipes on the desired alignment required for pulling of pipeline string during HDD operation, preparation of pipeline string of coated linepipe, associated fittings and accessories, etc.Taking delivery and transportation of Owner-supplied 3LPE coated pipes to the work site from designated stockpile location, inspection of the coated pipes visually and/or with holiday detector for defects, including arranging all necessary intermediate storage area required thereof till the pipes are installed in permanent position, including executing all works; arrangement of all additional land or working space required for string preparation/during pulling (if required), Contractor's storage, fabrication, access for construction; supply of all materials (except Owner supplied materials), consumables, labour and other incidental works; return of the surplus pipes to the Owner's designated stockyard(s); carrying out all temporary, ancillary, auxiliary works required to make the pipeline ready for insertion by HDD method as per drawings, specifications, scope of work indicated in tender documents and other provisions of Contract document and instructions of Owner, including but not limited to carrying out the following works:

Complete site preparation including arranging of required land, setting up of fabrication yard, preparation of temporary arrangement for pipeline stringing, launching etc. Carrying out repair of pipe defects, replacement in the case of non-repairable defects and repairing damages to pipe coating including defects/ damages occurring during transportation and handling. Pre-construction surveys and collection of all necessary data.

Stringing of line pipes along the desired & approved alignment required for pulling of pipeline string during HDD operation including providing straw/ sand/ soft soil bags, soft padding/ sand padding. Aligning, bending, cutting and bevelling (as required) of pipes for welding and field adjustments, welding, carrying out destructive/non-destructive testing of welds as required as per specification including 100% radiography by X-Ray/ and providng all requisite equipment, labour, supervision, materials, films, consumables all facilities and personnel to process, develop, examine and interpret radiographs and other tests, as required, carrying out repairs of weld joints found defective by Owner, carrying out re-radiography and other tests such as ultrasonic etc. as required on repaired joints etc. as mentioned in tender documents or instructions of the Owner/ Consultant.

Carrying out cleaning through water filling, pre-hydrotesting, of complete pipeline in one section/ test sections as approved by Owner to specified test pressure (1.5 times of the design pressure) for minimum 6 (six) hours holding period; providing all equipment, pumps, test headers, fittings, pressure & temperature instruments etc., and services, supervision, labour, consumables, water, air, etc. as required; detection of leaks, if any occurred during pre-hydrotesting, attributable to Contractor and rectification of defects, re-testing after rectification with due approval of Owner, successful completion of pre-hydrotesting including dewatering of pipeline to acceptance criteria defined in the specifications.

Carrying out cleaning/ flushing, gauging, pigging, post installation hydrostatic testing, swabbing, drying, magnetic cleaning and electronic geometry pigging, as per specifications, codes, approved drawings, calculations, methods and as directed by engineer-in-charge and provision of contract document

(Note : Leak detection, its rectification and successfully re-hydrotesting shall be carried out by Contractor with a view that completion of all activity for successful pre-hydrotesting is not inordinately extended, which will hamper the overall project schedule. Further, no extra payment claim shall be entertained for re-hydrotesting, leak detection and their rectifications if defects found attributable to Contractor.)

Carrying out tieing-in and hook-up of pipe with existing pipeline to match the site requirement, welding, carrying out 100% radiography, field joint coating, holiday detection, repair of damaged coating, backfilling and making through the pipeline etc. complete in all respects as per specifications and directions of Engineer-in-Charge.

All welded joints of pipeline string shall be 100% radiographically tested by X-ray and supply of films & all equipment and providing all facilities to Owner's representative(s) for examining radiographs, repair of defects in the welds and re-testing etc.