multiple large product supply tanks 14 which store a certain quantity of the agricultural product typically a particulate material e g seed and or inoculant or fertilizer and a metering system that meters the particulate material from the tank or tanks 14 to the air drill in addition to being mechanically linked with the air drill the air cart 10 and the air drill are interconnected by an air product delivery system which includes a plurality of distribution lines air is supplied to the product delivery system by a fan assembly or other pneumatic source sometimes mounted adjacent the front of the tank 14 and near the metering unit alternately the fan assembly may be mounted rearward of the tank or adjacent a side of the tank as known in the art the fan creates a turbulent air flow that carries particulate material metered by metering system into and along air product distribution lines to the utilization implement for applying the air entrained product to an agricultural field the supply of particulate material in the tank 14 is occasionally replenished from a supply vehicle in the past the tanks have been refilled by auger or conveyor systems which may cause.