Inspection, Repair and Replacement of Prayon Filter Trays and Channels in PA Plant

Fabrication of Hollow Shafts of Prayon Filter Trays : Collection of required materials and consumables from store.Hollow shafts shall be fabricated out of salvaged 200 NB/ Sch 160 200 NB Pipe/Sch 160 CS pipe and end flange out of 25 mm MS plate.Transport the fabricated shafts and flanges to workshop for machining and collect them back after machining and transport to work site as per instructions from engineer in charge.

Encasing of Prayon Filter Shaft (Filter Hose Side) : Make required arrangements for the work.Remove the existing MS encasing on the HV9 shaft by grinding. Fabricate new encasing out of 6mm MS plate by rolling to required profile. Encase the shaft area with new encasing in two halves. Full weld the encassing on all joint areas. Suit the bearing on the bearing area by proper grinding. Inspect the flange for any repair. Damaged flange areas shall be welded and ground as per instructions.

Repair Works in Spare Filter Trays. Shift and transport the spare filter tray to earmarked area.Clean throughly the spare filter tray. Position the filter tray properly and suitably. Leak test the tray by filling water. All arrangenments for leak testing including fabrication and providing end dummies shall be done by the contractor. Inspect for leaks. Also inspect the trays for any surface cracks.Collect the required materials for repair from store and transport to work site.Repair the leaked and cracked areas by proper grinding the crack/leak area and repair welding with suitable electorode. Suitable pad plate is to be provided as per instructions.The welding area shall be DP tested and inspected by engineer in charge. After the repair welding is successfully completed, leak test the tray again.Once the leak test is successfull drain the water and transport the tray to earmarked storage area as per instructions from engineer in charge, the tray has to be neatly and safetly stacked. The leak test for the trays have to be carried out as many number of times till the test reuslt No Leak obtained. All arangements for leak test will be under contractor's scope.

Replacement of Filter tray End Hollow Shaft (Cell Control Lever Side) : Clean throughly the filter tray. Shift and transport the filter tray to the earmarked area.Assemble the filter tray on the fixture and perfectly. Provide steady pins for firmness.Grind the cladding on the shaft.dismantle/cut the existing end shaft.Prepare the edges with proper grinding.Assemble new shaft,properly align the shaft with the filter tray. Full weld the shaft with the tray using suitable electrode. Properly grind the weld joint and carry out DP test. Any flaw detected will have to be reworked. Provide stiffeners for the weld joint area with the tray as required.After complete welding and grinding provide an encasing of HV9 material covering the weld joint area and on hollow shaft upto the bearing area, and full weld on the encasing using suitable electrode as per instructions from engineer in charge.Once the replacement work is complete, unmount the tray from the fixture and transport the tray to the stacking area as per the instructions from engineer in charge.Clear the site and transport the scrap to area earmarked/scrapyard.

Fabricate Filter Support Channel : Collect the required material from store and transport to work site. Take measurement from exsiting filter support channel,using MS ISMC and MS plate as per the instructions from enginner in charge. All joints shall be full welded. Pad plates shall be provided at required areas/joints and shall be full welded as per instructions from concerned engineer. All welding areas shall be properly ground to facilitate rubber lining. Once the fabrication is complete shift and transport the channels to rubberlining area for rubberlining. After completion of rubberlining transport the support channel to stacking area and safety stack the channles as per instructions.

Replacement of Prayon Filter Support Channel : Transport the spare support chanel to prayon filter site. Collect the required tools/tackles/consumables from store/work shop. After getting process clearence and postioning of filter trays, cut and dimantle the existing support channel. Grind and finish the welding areas on the filter frame. Erect the new support channel to the required position. Properl position the channel and correct the alignment of the channel with the frame.Properly/full weld the joint areas with the channel and filter frame. Take trail run and confirm the position of channel is correct with the position of the tray and there is no entangling of filter tray with the channel. Any rework arising out of this ie, repositioning and re welding of channels etc.shall be done as per instructions from concerned engineer. After successful trial run, clear the site and transport the scrap to area earmarked/scrapyard.

Replacement of Prayon Filter Tray : After getting process clearence dismantle the splash guards, cell control lever, filter hose etc. of the tray to be replaced. Dismantle the CI bearings of the tray. Shift and transport the tray to the repair bay. Repair the tray for the damage/cracks etc. Set new CI bearings on the filter shafts. Ensure the bearings suits the filter shafts (bearings have only design clearence with shaft) under the supervision of concerned engineer. Shift and transport the repaired/spare tray assembly to the site and erect the filter tray to position. Position the CI bearings on the frame and properly tighten the base bolts and cover bolts. Mount the control level assembly, filter hose and splash guards etc. Take trial run and ensure the tray doesnt entangle with other trays/filter support channel. Any rework arising out of this shall be done by the contractor. After successful trial run clear the site and transport the scrap to earmarked area/scrap yard as per instructions.

Fabrication of Filter shoes : Collect the required material from store and transport to work site. Take measurement from exsiting filter shoes fitted on support channels, using MS plate of 12mm & 8mm thick as per the instructions from Enginner in charge. All joints shall be full welded. All welding areas shall be properly ground to facilitate rubber lining. After fabrication completed, transporting the shoes near to support channel stacking area as per instructions.

Supply/unloading and Handing over of 650/1100V, Copper conductor PVC insulated, armoured PVC outer sheathed cable of size 5 cores x 2.5 sq.mm. The cable shall be supplied at Q10 installation of FACT at Willingdon Island and must be unloaded as per the instruction of engineer-in-charge. Vechicles/loading and unloading shall be in contractors scope