Fabrication and Replacement of Roof of Weak C Phosphoric Acid Storage Tank in PA Plant, FACT-CD.

Fabrication and Replacement of Roof of Weak C Phosphoric Acid Storage Tank in PA Plant, FACT-CD.

Dismantle Storage Tank Roof : Collect and transport required tools and tackles for the work. Make necessary site arrangement for dismantling,including scaffolding inside and outside the tank.Decouple and dismantle the agitator and gearbox, and motor. Transport them to earmarked area. Dismantle and shift the pipelines, launders,platforms from tank roof and provide temporary support for them sothat plant activities are not affected during the work period. Any other arrangements required for smooth functioning of plant may be arranged by the contractor as per the instruction from the Engineer -in- charge. Cut and dismantle the tank roof completely in pieces Support structurals/walkways/nearby platforms/stairs etc shall also be dismantled as per the instruction from Engineer in charge. The cut pieces shall be transported to scrap yard in complete after weighing. The site shall be cleared of scrap. Tank shell shall be provided with temporary supports to avoid buckling.Main platform/structural shall be dismantled if required.Rubber lining removal for cutting the roof shall also be done. Dismantled scrap shall be weighed and transported to scrapyard. Dismantled platforms,walkways.assosiated structurals shall be presrved for erection.

Fabrication of Storage Tank Roof : Collect the required materials,tools,tackles etc from store/workshop and transport to site. Take measurement from existing Phosphoric Acid Tank and also refer drawing FEDO EQPT NO.3.2206 Spec. No 0716-335-3.226. Fabricate the entire roof in segments / pieces with supporting trusses / structures and all accessories including nozzles, flanges, provision for guages etc.Plate thickness of the roof shall be 6mm.Mark and cut the new MS pates (06 mm thick) to correct size and grinding the plate edges properly with suitable bevel / single vee, where the welding is to be done. Roof stiffening members like rafters, vertical column, rafter stays, ties, purling, cleats, gusset plate etc. shall be fabricated a maintained as per the original drawing/existing condition. Necessary temporary supports if required upon instructions from concerned enginner are to be provided / fabricated inside the tank to facilitate the erection of the roof. All manholes / nozzles with flanges etc. as per the drawing/site conditions shall be fabricated. Foundation bed for agitator gearbox shall be fabricated as per site conditions/relevant drawing.The roof of the tank shall be fabricated and erected in such a manner that overall symmetry, shape and overall dimensions as per the drawing are to be maintained. Handrails,stairs from main walkway to roof, additional walkways on the roof top etc. shall be fabricated as per site instructions. All weld joints shall be full welding only. All weld joint (Inside area) of roof and roof joining area to the vertical shell of the tank shall be thoroughly / properly ground to facilitate for rubber lining.Erection hooks shall also be welded to the roof.Holes for water draining facility shall be provided on each stiffeners. After complete fabrication clear the site and trasport the scrap to scrapyard. Unused plates/structurals shall be stacked at areas earmerked. ( Weight taken will be total weight of roof including rafters, coloums, ties, nozzles,foundation bed for gearbox etc.)

Erection of Strong A Sorage Tank Roof: Make required site arrangements for the work including scaffolding. Collect required materials from the store. Transport the fabricated roof from yard to work site.Temporary cross supports shall be provided inside tank shell to avoid buckling. Any temporary structures shall be provided suitably for ease of erection. Any repair on the kerb channel shall be done. Ovality of the tank shell shall be corrected before erection of roof. Erect the roof in full/or in segments as per the site conditions/availability of the crane. Erected roof shall be set and fit up shall be done. The joints shall be welded inside and outside. All welding shall be full welding only. The inside of tank roof joints shall be properly ground to facilitate rubber lining. Once the erection of roof is complete, the agitaor,gearbox and motor shall be transported from respective workshops and erected at site.The agitator, gearbox and motor shall be coupled and all foundation bolts be full tightned. All incoming and outgoing pipelines/launders shall be erected back. All guages, nozzles, level switches etc.shall be transported and erected at site to original condition. Lauders, pipelines & other walkways temparorily supported, which are mentioned in Item no1 shall be fixed back on the roof . All stairs,handrails etc. shall be erected and full welded. The roof of the tank shall be fabricated and erected in such a manner that overall symmetry, shape and overall dimensions as per the drawing are to be maintained.Any additional walkway requirement shall be done, fabrication and erection as per site instructions. Once the erection work is complete all temporary supports shall be removed. The main walkway/platform/structural shall be dismantled if required for ease of erection and shall be erected back after roof work is completed. Any additinal strengthening required shall be done.

M A ALI

M A Shamsudeen

VIKRAMAN NAIR S

M M THAMBI

BABY B

S K BOILERS PVT LTD