PACKAGE : I Bid Document VOLUME : II - Public Health Engineering

The gears between the driver and driven impellers shall be of nickel cast steel, or
other approved material accurately ground with close clearance to prevent
interference between impellers.
The casings shall be of high grade cast iron adequately ribbed to avoid distraction.
Adequate facilities shall be made for rotor inspection.
Each blower shall be constructed such that each rotor impeller runs on external ball
or roller bearings and is driven by external gearing to ensure that the air produced is
completely free of oil.
All interconnection pipe work between the compressors and the rings main to the
filters together with the necessary isolating valves shall be supplied by the
Contractor in at least 250 mm dia. flanged, steel pipe work and provided with
valves to drain off condensed water from low points. Wall mounted pressure gauge
shall be provided in the filter gallery and adjacent to each machine.
21.26 Wash water pumps.
Suitable centrifugal pumping plant with (50% stand by) all accessories to fill up
over head wash tank.
21.27 Wash-water pipes.
The wash water delivery pipe work shall be connected to main filter gallery
distribution mains, arranged to prevent air locking and fitted with means of
expelling trapped air from the highest point, and drainage from the lowest.
21.28 Filter battery access walkways.
Contractor shall include sufficient elevated pedestrian access ways with handrailing,
to enable the operational staff to have ready around all the filters and, above
ground level to the inlet works. All walkways shall be a minimum of 1.5 m wide.
DTS : Detailed Tender Specification. Page 255