Specifications

Enquiry Specification for Wagon Tippler with Side Arm Charger and Associated works
NRO/CON/WT/533
EPI – New Delhi Volume-2B, Rev.0 Page 15 of 63
coupled to motor with flexible coupling. Spacer type coupling shall be provided.
Pump shall conform to IS: 1520.
Pump shall give satisfactory performance at any point on the H-Q curve over a
range of 40% of rated flow to 120% of the rated flow. The maximum efficiency
shall preferably be within ± 10% of the rated design flow. The total head -
capacity curve shall be continuous rising towards the shut off without any zone
of instability and with a minimum shut-off head of 15% more than the design
head.
Pumps shall have shaft seal by gland packing. Pump shall be fitted with double
wearing rings , one is fitted in the front of the impeller on the casing and the
other is fitted in the back of the impeller on the impeller itself.
Impeller shall be dynamically balanced. The magnitude of peak to peak
vibration shall be limited to 75 micron. Pump impeller shall be non overloading
type. Impeller shall be made in one piece & keyed to the shaft.
- Material of construction
Casing - C.I
Impeller - Bronze
Bearing Bracket - C.I
Shaft protection sleeve - Bronze
Wearing ring - Bronze
Shaft - EN-8
Common base frame for pump & motor - M.S
Common base plate for pump & motor shall be in one piece & made of welded
steel construction. Adequate space shall be provided between pump drain
connection and base plate for installation of minimum 15 mm drain piping.
Pumps shall be supplied with suitable drain pans or drain rim type base plates
with tapped drain connections.
Critical speed of the shaft shall be at least 30 percent above the operating
speed.
(6) Water Piping and Fittings
Water piping up to 150 mm NB size shall be GI, ERW, heavy class and
conforming to IS-1239 Part- 1 . The pipes above 150 NB shall be MS, spirally
welded , 6 mm thick and conforming to IS:3589. Pipe ends shall be beveled.
Pipe fittings shall be as per IS 1239, Part -2 for pipes of size up to 150 NB.
Fabricated fittings manufactured from the pipes may be provided for pipes of
sizes 200 NB & above.
Plate type pipe flanges (as per IS 6392) shall be provided.
Pipes shall be of welded joints. Welding (manual metal arc welding) shall be as
per relevant IS code and only certified welders shall be employed.
All piping systems shall be hydro tested at 1.5 times the design pressure.