Bid Package 08 North Well Field - Garney Construction

Colorado River Municipal Water District
Vertical Turbine Submersible Pumping Units
Ward County North Well Field
be designed to operate at 1,800 rpm, at 480 V or 2,300 V, 3 phase, 60 Hz,
alternating current, with full voltage (across the line) starting capability with a
maximum current inrush of 500% without use of special starting equipment. The
motor shall be a high reactance type design that will provide an inrush current
that is low enough to allow across the line starting. The entire motor shall
incorporate an insulation of Class B or better. Motor shall have a NEMA code
letter of E or less (i.e., locked motor KVA per horsepower shall be 5.0 or less).
Motor enclosure classification shall meet or exceed IP68 requirements.
2. The motor shall be equipped with a bellows type mechanical seal, one and/or
two. The seal material shall be 316SS bellows, Tungsten Carbide-Nickel rotating
face, Viton gaskets or Engineer’s approved equal. Seal(s) shall be located in the
top of motor near where the shaft extends through the motor housing. Seals
placed back to back are unacceptable if two are proposed. Provide lip seal on
shaft outboard of mechanical seal.
3. The motor design shall automatically balance the internal pressure in the motor
with the well pressure (submergence pressure) outside the motor. Provide
suitably sized neoprene rubber membrane/diaphragm bellows to allow for
expansion as the internal water heats or the external pressure increases with depth
of set.
4. The motor shall be equipped with a pivot type bidirectional double axial thrust
bearing capable of carrying the weight of all rotating components including the
hydraulic thrust of the pump (up-thrust and down-thrust) of the pump at shutoff
head. It shall be rated at no less than 20,000 pounds of thrust in either direction
or the actual thrust plus a safety factor of 2.0 in either the up or down direction;
whichever is greater. The pump manufacturer shall supply calculation for downthrust
and up-thrust with their submittal and substantiate the thrust bearing
capacity. The thrust bearings shall be lubricated and cooled by the motor internal
circulating system. The main rotating disc of the axial thrust assembly shall be
stainless steel 431 and rotate between two graphite or composite graphite shoe
assemblies. Substitutions permitted with approval of the Engineer.
5. The water cooled/lubricated motor shall also have the following properties:
a. Aggregate materials of construction:
1) Main frame in cast steel St-52 type construction.
2) Bearing housing and motor base, cast iron.
3) Rotor shaft, AISI 416 SS or better.
4) All wetted fasteners and washers shall be 316 SS.
5) Motor and pump shall be coated with two applications of an
NSF-approved high performance coating system made for
continuous submergences applied over an SSPC-SP10, 2- to
3-mil surface preparation. Total dry film thickness shall be
between 10 and 12 dry mils.
6) Provide replaceable radial bearings, bronze and graphite, with
grooved profile over graphite surface, water lubricated, with
large surface area and length to maximize side support and
reduce lateral movement to an absolute minimum.
7) Winding conductor shall suitable for continuous submergence.
At a minimum, winding conductors shall be copper with a
January 2012
Submersible Vertical Turbine Pumping Units
Revision 0 11210 - 8