NCTPS I SE MI circle Boiler Maintenance Division Annual Overhaul work for the year 25 26 Specification No 91 25 26

Amount

Renewal of defective MSSV (Left) by reconditioned MSSV valve: Charges for making arrangements to facilitate leading, lifting of reconditioned MSSV valve from stores to site and old valve from site to stores. Cutting, removal and re-erection of existing platforms, structural members at 52 M level. This work involves cutting, removal and re erection of existing platforms, structural members to facilitate movement of new & old valves for replacement of defective MSSV, arranging scaffolding wherever required for cutting, lifting and lowering the structural members. Including consumable and hire charges for T&P's.

Charges for drawl of 1 no. new Main steam stop valve (MSSV) from stores, leading lifting and transporting to boiler area, arranging scaffoldings, sling were ever required, leading & lifting the new MSSV to the boiler 52mtr level at right side, lowering released defective MSSV to the ground flower and devolution the defective valve to stores. Including consumable and hire charges for T&P's.

Charges for transportation of T & P’s, Platform Materials, gas and other consumables to the work area, arresting the M.S Line with proper supports, cutting the defective valve, after completion of work normalizing the M.S Line. Including consumable and hire charges for T&P's.

Dismantling of defective Main stem stop valve (MSSV) (Left): Providing chain block arrangement, dismantling of electrical actuator and motor assembly of 350 NB MSSV valve by loosening of all bolt and nuts. Dismantling of yoke assembly of valve by loosening and releasing of heavy size 16 Nos HT bolt & nuts. using chain block arrangement, lead, lift of material to 52 mtr elevation of boiler. Including Consumable & T&P's.

Dismantling of total gland bolts and gland collar, bonnet clamp bolts, heavy size bonnet clamp,bonnetarrestting split rings by using 7 ton capacity chain block arrangement, special heavy duty fixtures and 2 X 100 Tons capacity hydraulic jacks by lifting , lead, lift complete at 52 mtr elevation of boiler. Including consumable and hire charges for T & P's.

Dismantling of heavy size bonnet assembly with heavy size stem 100 mm Dia X 2 Mtr length with valve disc by using 7 tone capacity chain block arrangement, special heavy duty fixtures and 2 X 100 Tons capacity hydraulic jacks by lifting , lead, lift complete at 52 mtr elevation of boiled. Charges including consumable and hire charges for T & P's.

Fabrication of special type heavy duty Fixtures for facilitating to dismantle the heavy size Maín steam stop valve internals such as bonnet clamp, bonnet, split ring, packing, support ring and Gate disc during Capital overhaul. (a)Fabrication of special type heavy duty fixture for facilitating to dismantle the heavy size bonnet clamp of Main Steam Stop Valve from valve body by insitue fabrication method. The work involves transporting, leading and lifting of required heavy steel materials to 52 metre elevation of boiler, designing of special type heavy duty fixture based on site condition, marking of fixture for the designed shape, Gas cutting and grinding of MS materials, welding of fixture to match with the site condition to facility for releasing of heavy size bonnet clamp from valve body, valve steam with Disc. Including consumable and hire charges for T & P's.

Charges for cutting of existing MSSV by grinding9, edge preparation of existing M.S Line& new valve, positioning, aligning and fitting the valve with main steam line, pre heating the MSL line for valve welding, DPT, Radiography testing the weld joints, post heating, stress relieving and mounting the actuators and commissioning the valve after completion of works. Charges for cutting of existing MSSV by grinding, edge preparation of existing M.S line & valve. Including consumable and hire charges for T&P's.

Valve positioning, Alignment & Fitting the valve with M.S. Line. Including consumable and hire charges for T&P's.

Preheating the welding area of MSSV pipe line with MSSV valves (heating coils and welding transformer ar to be arranged by the contractor)

Stress releaving the welded area of the line.

Commissioning of Rectified and assembled MSSV by manual operation of full open and full close and adjusting of gland packing tightness and adjusting valve stem upper and lower travel limit for calibration of limit switch level, retightening of all bonnet bolts after conducting hydraulic test and again tightening after syncronising of unit at hot condition, leading and lifting upto 52 mtr elevation of boiler. Including consumable and hire charges for T & P's.

Valve actuators mounting and commissioning the valve operation. Including consumable and hire charges for T & P's.

ferrofabs (BID ID -1393499)