Sanitary Sewage Pump Stations - The City of Wentzville | Missouri

pumping unit to the discharge connection elbow shall be accomplished by a simple lineardownward motion of the pump. A sliding guide bracket shall be an integral part of the pumpunit. No portion of the pump shall bear directly on the floor of the sump. The pump, with itsappurtenances and cable, shall be capable of continuous submergence underwater without lossof watertight integrity to a depth of 65 feet.403.4 Pump Construction. Major pump components shall be of gray cast iron,Class 30, with smooth surfaces devoid of blowholes and other irregularities. Where watertightsealing is required, O-rings made of nitrile rubber shall be used. All exposed nuts and boltsshall be of ASTM A 167 304 stainless steel. All surfaces coming into contact with sewage, otherthan stainless steel, shall be protected by an approved sewage resistant coating.All mating surfaces where watertight sealing is required shall be machined and fitted with nitrileO-rings. Fitting shall be such that sealing is accomplished by metal-to-metal contact betweenmachined surfaces. This will result in controlled compression of nitrile rubber O-rings withoutrequirement of a specific torque limit. No secondary sealing compounds, rectangular gaskets,elliptical O-rings, grease or other devices shall be used.The cable entry water seal design shall preclude specific torque requirements to insure awatertight and submersible seal. The cable entry shall be comprised of a single cylindricalelastomer grommet, flanked by washers, all having a close tolerance fit against the cableoutside diameter and the entry inside diameter and compressed by the entry body containing astrain relief function, separate from the function of sealing the cable.The assembly shall bear against a shoulder in the pump top. The cable entry junction chamberand motor shall be separated by a stator lead sealing gland or terminal board, which shallisolate the motor interior from foreign materials gaining access through the pump top. Epoxies,silicones, or other secondary sealing systems shall not be considered acceptable.The junction chamber, containing the terminal board, shall be sealed from the motor byelastomer compression seal (O-rings). Where a seal junction chamber is not used, the motorchamber shall be fitted with a moisture detection probe. The probe shall be connected to andactivate a warning light in the control panel. Specialized relays/sensors, if required by the pumpmanufacturer, shall be supplied to the control panel manufacturer by the pump manufacturerprior to panel construction.Connection between the cable conductors and stator leads shall be made with threadedcompressed type binding post permanently affixed to a terminal board and thus perfectly leakproof.Each unit shall be provided with an adequately designed cooling system. When thermalradiators (cooling fins) are used, they shall be integral to the stator housing and shall beadequate to provide the cooling required by the motor. When water jackets are used, the waterjacket shall encircle the stator housing. The water jacket shall be provided with a separatecirculation of the pumped liquid. Cooling media channels and pars shall be non-clogging byvirtue of their dimensions. Provision for external cooling and flushing shall be provided.Regardless of the cooling system used, the motor must be capable of pumping under full loadcontinuously with the water level only to the top of the volute. Motors with intermittent full loadratings or motors requiring oil for cooling will not be allowed.City of WentzvilleConstruction Specifications and Standard DetailsEffective Date: 06/10/09 400 -9