overhauling of boiler non - pressure parts ( aph, air / flue duct ) for unit # 3.- 1 cleaning of tube chokage for aph 2 ferruling for aph 3 erection new of expansion bellow for aph 4 fabrication , removal & refitting ( of guard plates on expansion bellow for aph. ) 5 fitting of liner plates on beams at top ( & intermediate aph tube bank ) 6 blanking of tubes for aph 7 checking & repairing of air / flue ducts ( esp damper & aph hoppers. ) 8 erection of air / flue duct expansion ( bellow ( single leaf ) . ) 9 replacement of cloth type expansion ( bellow at esp i / l & o / l. ) 10 fabrication & erection of guard plate ( for expansion bellow of air ducts / flue ducts. ) 11 repairing / replacement of aph / hot air ( duct / wind box casing. ) 12 old expanding failure aph tube ( re-expanding / welding. ) 13 hiring of escort crane with operator 14 cleaning of tubesfor aph by lp ( water jet. ) 15 replacement of damage support beam ( partly along with top bearing plate of air / flue duct. ) 16 checking, servicing or renewal of roller ( bearing of air / flue duct. ) 17 removing & re-application of insulation ( work for boiler casing & air / flue duct. ) 18 de-insulation & re-insulation of steam ( steam / water pipe upto 4 with old / new material. ) 19 de-insulation & re-insulation of steam ( / water pipe above 4 with old / new material. ) 20 de-insulation & re-insulation of steam ( valve upto 4 with old / new material. ) 21 de-insulation & re-insulation of steam ( valve above 4 with old / new material. )