Volute design for lower manufacturing cost and radial load reduction

A volute (VI) for a pump comprising:

• a volute wall (VWall);
• a pump inlet (i) for receiving a fluid being pumped;
• a pump discharge (o) for providing the fluid being pumped;
• and
• a casing vane (CVI) configured on the volute wall (VWall) forming double volutes in the volute (VI) and being configured with an upper cutwater (C2) farthest from the pump discharge (o) defining an upper cutwater throat area (2′) and an end of passage (4′) for the upper cutwater (C2), and also configured with a lower cutwater (C1) closest to the pump discharge (o) defining a lower cutwater throat area (1′) and a corresponding end of passage (3′) for the lower cutwater (C1), the fluid flowing in the volute (VI) in a direction from the upper cutwater (C2) to the lower cutwater (C1) and out the pump discharge (o), the upper cutwater (C2) being configured on an upper cutwater axis (Ac1) with respect to the pump inlet (i), the lower cutwater (C1) being configured on a lower cutwater axis (Ac2) with respect to the pump inlet (i), the upper cutwater axis (Ac1) and the lower cutwater axis (Ac2) being radially displaced at an angle α that is substantially less than 180° in radial separation with respect to the pump inlet (i) and in the direction of the fluid flowing in the volute (VI) from the upper cutwater (C2) to the lower cutwater (C1) and out the pump discharge (o);
• the upper cutwater throat area (2′) being dimensioned to be greater than and not equal to the lower cutwater throat area (1′) so that the upper cutwater throat area (2′) and the lower cutwater throat area (1′) provide substantially equal flow velocity at both the upper cutwater (C2) and the lower cutwater (C1) in response to an angular sweep of the fluid being pumped;
• and
• the end of passage (4′) for the upper cutwater (C2) being dimensioned with an upper cutwater passage area that is greater than and not equal to a corresponding lower cutwater passage area of the corresponding end of passage (3′) for the lower cutwater (C1) so that upper and lower cutwater passage areas at the pump discharge (o) are balanced as a function of differing rates of flow of the fluid being pumped therein and so that the fluid being pumped from associated ends (3′, 4′) of the upper and lower cutwater passage areas meets at the pump discharge (o) with a substantially equal velocity.