Pneumatically driven fluid pump apparatus, comprising: a pump casing ; a pump cap secured at a first end of the pump casing ; a liquid discharge tube in communication with the pump cap and extending at least partially within an interior area of the pump casing toward a second end of the pump casing , and where fluid is admitted into the pump casing at the second end; a fluid discharge tube communication with the pump cap for receiving liquid collected within the pump casing and discharged through the liquid discharge tube ; the pump cap including: a first portion for receiving a pressurized airflow from an external pressurized air source, where the pressurized air is used to help displace liquid collecting within the pump casing upwardly through the liquid discharge tube ; and a second portion in communication with the first portion and also with the interior area of the pump casing , characterized by the second portion being configured to direct the pressurized air received through the first portion toward an interior wall portion of the pump casing so that a swirling airflow within the casing is created, the swirling airflow moving in a swirling manner toward the second end of the pump casing to help clean the interior wall portion of the pump casing , while also imparting a swirling action to the liquid having collected within the pump casing , and ejecting the swirling liquid upwardly into and through the fluid discharge tube. a pump casing ; a pump cap secured at a first end of the pump casing ; a liquid discharge tube in communication with the pump cap and extending at least partially within an interior area of the pump casing toward a second end of the pump casing , and where fluid is admitted into the pump casing at the second end; a fluid discharge tube communication with the pump cap for receiving liquid collected within the pump casing and discharged through the liquid discharge tube ; the pump cap including: a first portion for receiving a pressurized airflow from an external pressurized air source, where the pressurized air is used to help displace liquid collecting within the pump casing upwardly through the liquid discharge tube ; and a second portion in communication with the first portion and also with the interior area of the pump casing , characterized by the second portion being configured to direct the pressurized air received through the first portion toward an interior wall portion of the pump casing so that a swirling airflow within the casing is created, the swirling airflow moving in a swirling manner toward the second end of the pump casing to help clean the interior wall portion of the pump casing , while also imparting a swirling action to the liquid having collected within the pump casing , and ejecting the swirling liquid upwardly into and through the fluid discharge tube. a first portion for receiving a pressurized airflow from an external pressurized air source, where the pressurized air is used to help displace liquid collecting within the pump casing upwardly through the liquid discharge tube ; and a second portion in communication with the first portion and also with the interior area of the pump casing , characterized by the second portion being configured to direct the pressurized air received through the first portion toward an interior wall portion of the pump casing so that a swirling airflow within the casing is created, the swirling airflow moving in a swirling manner toward the second end of the pump casing to help clean the interior wall portion of the pump casing , while also imparting a swirling action to the liquid having collected within the pump casing , and ejecting the swirling liquid upwardly into and through the fluid discharge tube. <EOS>