Certification of Six months for three Vertical Boilers (Sl. Nos. BR 7271, BR 6919 and WBL 9857) at Amkola Unit of Nimcha(R) Colliery

Amount

Item description

The above boiler is to be dismantled thoroughly and the same is to be cleaned byscrapping out of all the hard scale inside the boiler manually and inner firebox is to be cleaned as per IBE 50

All the mounting fittings such as stop valve, safety valve, gauge coloumn cock,feed check valve, blow down valve are to be dismantled and cleaned for inspection by Dy Director of boilers

The defective fusible plug is to be removed and the mounting pad to be repaired by necessary build up and rethreaded in original manner.Then new fusible plug is to be in IBR approved manner

The vertical boiler needs to be lifted using hydraulic boiler jacks from three sides so that the damaged base plate can be cut out using oxy0acetylene cutter

The foundation brick work needs to be repaired including materials

The defective rivets from the foundation seam are to be cut out and reemoved from the boiler as Director by the Asst. Directors of Boilers

The wasting places of the foundation rivets area are to be build up by BQ electrodes and dressed smooth

The enlargeed rivet holes are to be repaired

The boiler quality new rivets are to be forged steel as per IBR50

The new BQ rivets are to be fitted to the boiler in approved manner

The wasting shell extension plate are to be cut and removed,Then new plate are to be fabricated and fitted to the boiler by necessary welding as per IBR approved manner

Finally the boiler needs to be reseated with proper alignment on the new foundation

The staggered and isolated pitting were noticed upto 2mm was found on the up-take tube,The position where the thickness gauging was carried are to be built up by electric arc welding with pre-post heating treatment and dressed smooth to original shape and thickness

The furnace crown was found to be pitted locally at isolated places between 4 o'clock to 8 o'clock position on water side.The position where the thickness gauging was carried are to be built up by electric arc welding with pre-post heat treatment and dressed smooth to original shape and thickness

The mud hole cover area are to be build up with pre-post heat treatment and dressed smooth to original shape and thicknessmaintaining the spigot clearance to upto 1mm.All mud plugs studs are to be replaced with new ones

The gauge column cocks are to be repaired by replacing all the worn out spares and reassembled the same in original manner….02 sets

Repairing of stop valve including its dismantling,welding,machining, grinding where everequired of valves and seats.Then the valve is to be reassembled and refitted in existing manner

Repaiirng of safety valve including its dismantling,rebuilding with proper materials,maching grinding uo to leak proof.Then it it to be reassembled and refitted in existing manner

The blow down valve is to be dismantled throughly and inner spares and mounting studs are to be replaced with new ones.Then fitted to the boiler with necessary joint packings upto running order

The feed check valve worn out SSNRV is to be dismantled and to be rebuild by SS welding & machining & grinding throughly then reassembled the above valve with necessary joints packing etc. & to be fitted up to running order

The fire door caulking edge has to be V cut and then welded with pre-post heat tratment and then dressed smooth. Aftewelding the edge has to be caulked up to leak proof

The fire door plate was getting damaged due to constant firing of boiler hence as advised by Dy. Director of Boilers, a new protection cover needs to be made over the bottom half of the fire door

Charges for necessary blanking the boiler with necessary joint packings etc. and then the boiler is to be tested hydraulically at apressure of 150PSI

Charges for fitting all the valves and mounting fittings with necessary high pressure steam joints, asbestos tape joint etc. The boiler is to be made rerady for commissioning

Total impact of GST for the purpose of CTC

M/s Prasanta Karmakar (BID ID -1118198)