NCTPS II MI Circle BM Division Unit I Boiler Routine Maintenance Attending Boiler

Charges for air cleaning and water washing the boiler tube puncture area to facilitate boiler tube rectification works.

Assistance and inspection for Boiler Hydraulic test when the unit is in standby condition. This work comprises of assistance for hydraulic test and inspection of Boiler at pressurized condition in boiler I st pass, Inter pass, II nd pass and Economiser hopper area and allied valve operations etc.,

Charges for transportation, Assembling and dismantling of Temporary maintenance platform / Sky climer for shut down maintenance works. a) Transportation of 1set of Temporary maintenance platform/ Sky climber along with ropes, hoist, power cable etc. from pocket store.

b) Opening/Closing of manhole doors, leading & lifting of platform to 11 mtr & transporting of ropes to 88 mtrs and providing temporary platform in 11 mtr level assembling of Sky climber inside the boiler.

c) Assembling / dismantling of Sky climber and removal of Temporary Maintenance platform / For one No. in 11 mtr inside the boiler:

Charges for shifting the sky climber inside the furnace for access of platen super-heater coils

Charges for operation of sky climber as per the requirements to assist various overhauling works such as Boiler cleaning, tube thickness survey etc., during the maintenance work period.

Charges for renewal of defective boiler tubes of size above 44.5mm OD inclusive of transportation, cutting of defective tubes, edge/spool preparation, welding with IBR welder and assisting for hydraulic test.

Replacing of Oxide scale deposited tubes /bends by new bends/ tubes : Cutting and removing of Oxide scale deposited re-reheater tubes / bends by arc cutting by using special electrodes for a affected length portion from the coil assembly, edge preparation of tube ends , Positioning and new tubes/ bends by tag welding.Welding the tube joint with IBR welder.(argon gas, welding generator, TIG set and special welding electrodes will be the scope of contractor.) Charges inclusive of cost of consumables and T&Ps.

Tube rectification by window cutting and welding. Marking of defective tubes identified, cutting of defective portion of tubes, edge preparation, welding of new spool piece with IBR welder. Window cutting on the tube, edge preparation, welding of new piece with IBR welder. Charges inclusive of cost of consumables and T&Ps.

Strengthening of existing joints: This work involves identification of less eroded existing joints, transportation of tools & plants and consumables,Grinding less eroded joints and strengthening the joints by welding with IBR welder

Arc filling i) Grinding of boiler tubes for arc filling size 150X 25M2 area for 3 layers.

ii) Charges IBR welder for Arc filling of area 25 x 150 M2 by 3 layer.

ii) Charges IBR welder for Arc filling of area 25 x 150 M2 by 3 layer.

Skin casing welding and patch work: This work involves removing the refractory, Cutting, the existing skin casing sheet wherever required, welding with new skin casing sheets, arrest the ash leakage. This including the cost of consumables scaffolding arrangements and T&P’s.

Charges for transporting the refractory from stores and unloading at site, leading, lifting, stacking at 7m to 52m elevation of Boiler and removing the waste refractory from Boiler lowering to the ground floor, loading to tipper and disposing at waste disposal area of TPS.

Charges for chipping removal of old defective refractory, cleaning, surface preparation, mixing the refractory with water application and curing the patch worked refractory in Boiler at various elevation.

Providing special type platform to access the rear re-heater coils for the entire re heater bottom area and back pass screen tube area for facilating Oxide scale thickness measurement / Renewal of oxide scale formed tubes / For facilitating Reheater vaccum pulling inspection.The charges for transportation of scaffolding materials and consumables to the boiler rear arch slope area, erecting at 64mtrs height for a width of 3 mtrs, scaffolding and temporary platform for facilitating attending the above work. After completion work, removing the scaffolding and temporary platform from the area and shifting back the scaffolding materials. Charges inclusive of T&P's and consumables.

Welding in minor damaged portions in Dock house area, pent house area, windbox area, S panel area