Inverted fluid dispensing pump and dispensing system, and method of using an inverted pump

A method for operating a pump, comprising:

• actuating a piston to decrease an interior volume of a piston body forcing fluid in the piston body out an outlet by a first pressure differential between the interior volume and an exterior region around the outlet;
• releasing the piston causing the piston to return to an unactuated position to increase the interior volume forcing fluid in a reservoir to move into the piston body through a port due to a second pressure differential between the interior volume and the reservoir;
• and
• sealing the port with a ball after the piston returns to an unactuated position and the second pressure differential falls below a threshold by magnetically attracting the ball to a valve seat of the port.

A valve system for controlling a flow of a fluid, comprising:

• a port;
• means for sealing the port;
• and
• means for magnetically attracting the sealing means to the port.