Automatic precision liquid loading control system

Claim 1

A fluid control system comprising: a mobile vehicle having a sealed tank and first and second pressure sensing conduit means fixed to the tank and each conduit means having an opening inside the tank for sensing differential pressure within the tank; the first pressure sensing conduit means sensing the pressure of a vapor space above fluid in the tank; a fixed station having supply means including a supply conduit for loading fluid into the sealed tank of the mobile vehicle; a controller system in the fixed station having first and second pressure transmitting conduit means separate from the supply conduit, the first and second pressure transmitting conduit means having connector means for detachably coupling to the first and second pressure sensing conduit means respectively outside the tank for transmitting the differential pressure within the tank to the controller system; the controller system further having means for measuring the differential pressure within the tank itself for producing a differential pressure set point signal when the differential pressure measurement is beyond a predetermined set point; high pressure means coupled to the first pressure transmitting conduit means for producing an absolute pressure set point signal when the pressure in the vapor space is above a predetermined pressure set point; and the controller system further including means coupled to the supply conduit for controlling the supply of fluid free of pressure measurement of the supply conduit and in response to either the differential or the absolute pressure set point signal.