Circulation Pump

A pump comprising:

• a pump casing;
• a pump chamber formed in the pump casing;
• an impeller disposed within the pump chamber, the impeller having a plurality of vanes forming an inlet and an outlet;
• a sealing plate, forming one side of the pump chamber;
• a motor for driving the impeller;
• wherein the pump casing is a monolithic object comprising:
• a main body having a first surface, a recess in the first surface, a suction port, a suction channel, a suction passage, a discharge port, and a discharge channel,
• wherein the recess forms a first opening in the first surface, the first opening is closed by the sealing pump to form the pump chamber, the recess having a second opening in a second surface opposite the first surface and a wall connecting the first surface to the second surface;
• the suction passage communicates with the recess via the second opening and is aligned with the inlet of the impeller;
• the suction port is connected to the suction passage by the suction channel;
• the discharge port is connected to the recess by the discharge channel which extends from a third opening formed in the wall of the recess;
• the diameter of wall of the recess remains the same or decreases along a direction from the first surface to the second surface;
• the diameter of the inner surface of the suction passage remains the same or decreases along a direction away from the recess;
• the inner diameter of the suction channel remains the same or decreases along a direction towards the suction passage;
• and
• the inner diameter of the discharge channel remains the same or decreases along a direction towards the recess.