Augmentation of existing 270 MLD capacity W.T.P. by modification in specification of Nine Nos. 9.1 MLD rapid gravity filter bed at filtration Unit-III for augmentation for increase in filter capacity efficiency

Amount

Supply Installation testing commissioning for augmentation of 9.1 MLD Rapid Gravity Filter bed by using stainless steel grade SS 304 all welded wedge wire screen lateral internal part of lateral should be duly assemble with HDPE/PVC base pipe duly perforated.coveredwithout any circumferential or longitudinal joints in screen section to facilitate direct retention of filter media (i.e.in between no support layer of gravel etc.)must be designed suitable filtrate rate upto 9m^3/hr/m^2 of bed area. The shape of the lateral will be decagon type. System should have properly designed perforation, distributed across the periphery & length of the base pipe to achieve required quantity of filter water, uniform back wash during washing process, stop any media losses during the filtration & backwash. Bed size 8.0 Mtr X 6.50 Mtr, approximate area of 52.00 met^ 2 of each bed. Each bed having two section. The lateral will be of 3.5“ OD made of SS304 with 200 to 350 micron slot screen based on 3” UPVC SCH-40 pipe)/HDPE pipe withone end collar of screen will be of SS 304 and other end cap of Lateral-will be of UPVC/HDPE ( Filteration Unit-III 2x5=10 Nos. Bed, 1 No. bed upgraded earlier. thus balance = 9 Nos. Bed )

Air Header Assembly :- Air header 3”/4’ Diam Sch-40/80 Main air header suitable length made of UPVC pipe to suit the bed length suitable fittings for air distribution or each lateral back wash system.

Accessories for air distribution & Fixing the laterals, Hexa Nuts, Nipples, Air Nozzles and Nipples, Washers, Nut & Bolts etc

HDPE/UPVC air clamps, saddle for 3 inch size & HDPE/UPVC Tee of 3 inch size for lateral fixing by grouting

Construction in RCC Air header beam and central manifold channel for collection of filter water & to distribute back wash water in both beds.

Supply of filter media as per CPHEO manual size from 0.4 to 0.8 mm to install up to depth of 800 mm in filter beds.

Supply of Gravel size between 10mm-15mm to be filled only in space between stainless steel lateral and install up to the hieght of Lateral.

Removal of old filter media, desilting, removal of sand, from the bed & dumping the old media & debris, Desilting the media from the bed with the help of manual labor to make the area workable. The work also includes removal of all floating material from the inlet channel & dumping the silt & floating material in to the sump yard.

Dismantling / Removal of existing system from the existing bed by using welding machine, cutting of nut bolts, making platform, tools and tackles, stair case and using safety precautions. All sytem will be lay down from the bed to the ground level by manual labor.

Demolish of Manifold Beam and excavation of the site inner bed area and collect the malwa from the side and transport to the disposal site near by WTP compound. Installation of temporary stands required at various levels to carry out the work inside the bed for the construction of filter bed work.

Erection & commissioning of Stainless steel grade SS 304 under drain screen lateral system , Air header assembly, Accessories for air distribution & Fixing the laterals, Clamps along with grouting of T in main header, fixing of lateral with Tee, leveling of laterals, fixing and grouting to other end of laterals, joining of air header line installation. Filling filter media, into filter bed upto required depth upto 800 mm.

Chahar Construction Co

SANTAJI R KADAM