Public Works Department Tender

Supply and delivery of submersible centrifugal sewage non-clog pumps, vertical spindle type pump, wear resistance with submersible motor for the various duty conditions as stated in the annexure, pump shall be capable of handling min lOOmm solid size with sewage specific gravity of upto 1.05. Pump shall be of robust construction. Liquid passages shall be finished smooth and designed as to allow free passage to solids. Pump impeller should be of non-clog semi open type, single vane multi vane preferably contra bloc or vortex impeller design. Double mechanical seal with sillicon carbide faces should be provided to protect the motor from ingress of sewage along the shaft. The critical speedof the rotor shall be at least 30% above the operating speed. Pumps to have double bearings between the pump & motor. The bearings life shall be minimum 100,000 hrs of operation with greased for life. Pump should be provided with automatic coupling device including pedestal, duck foot bend, stainless steel guide pipe or related accessories of suitable size to facilitate lifting and lowering into guide rails for easy maintenance. Pump shall be provided with a stainless steel lifting chain conforming to BS 970 Gr 304. Pump speed shall be of 9600 rpm for high duty pumps and 960/1450 rpm for low duty pumpsets. Casing and impeller should be of CI Gr. FG 260: IS 210 more preferably with hardened impeller. Shaft should be of stainless steel AISI 410. All the fasteners and

bolts shall be of AISI 410. The submersible motor shall be operated with 3 ph, 415 V (+ or - 10%), 50 Hz(+ or - 5%) dry induction type. Motor shall be capable of giving rated output without reduction in the expected life span when operated continously. The rotating assembly shall be dynamically balanced as per standards. The starting current of the motor shall not exceed 200% of rated full load current for Star Delta or ATS starting under any circumstances. The motor shall be suitable for full voltage Star Delta / ATS starting. The locked rotor current of the motor shall not exceed 600% of full load current unless otherwise specified. Motor shall be designed to withstand 120% of rated speed for two minutes without any mechanical damage, in either direction of rotation. The motor vibration shall be within the limit specified in applicable standards. Motor should be of IE2, explosion proof compatible for VFD operation together with star-Delta / ATS starter, protection against increase in stator winding temperature (15 deg Celsius), bearing temperature, leakage in the stator housing and terminal box shall be provided and to be suitably interlocked with the control panel for tripping the pump in case of increase in temperature beyond set limit.

Insulation class shall be of "Class H" and degree of protection shall be of IP 68 as per IS 4691. Motor shall be suitable for continuous operation in fully submerged or partially submerged condition. The pumpset shall be supplied with power cable of PVC insulated and PVC sheathed, copper, flexible, round type with required conductor size and number of cores as per starting method and of specified length for continuous use under water and air. The control cable of PVC insulated, PVC sheathed, flexible for stator winding temperature sensor 3 core x 1.5 sq.mm copper conductor and for bimetallic switches 2 core x 1.5 sqmm copper conductor shall be provided. Motor shall be supplied with lOmtrs of round submersible copper cable of suitable size. For a duty point of 25 - 30 m head and Discharge of 600 - 700 Cum/hour. The rate is inclusive of all taxes and activities such as Supply, Erection and Commissioning of motor pumpset other allied accessories such as control panel board with all accessories and Auto coupling, lifting chain with hand rail etc., as detailed above.