Apparatus and method for testing, filling and purging closed fluid systems

Claim 1

An evacuation unit for testing the fluid tightness of a closed fluid system having an access port and for filling the system with fluid through said access port, comprising: a first reservoir containing a first fluid; a second reservoir containing a second fluid; sequence valve means disposed between and communicating with said first and second reservoirs for selective positioning between a first position communicating said first reservoir with an outlet and a second position communicating said second reservoir with said outlet; vacuum pump means for producing a vacuum of a predetermined pressure less than atmospheric pressure, said vacuum pump means includes a source of air under pressure, a venturi, and conduit means interconnecting said pressurized air source and said venturi; connection means for releasable and sealable connection to an access port of a closed fluid system, said connection means includes a flexible hose having opposite ends, a filler head on one end of said hose for attachment to said access port, and coupling means on the other end of said hose; control valve means disposed between said coupling means and said vacuum pump means for selective positioning between a first position communicating said vacuum pump means with said connection means to produce a vacuum in the system, a second position isolating said connection means and system to test for fluid tightness, and a third position communicating said outlet of said sequence valve means with said connection means for filling the system with said first and second fluids; and a separation tank disposed between said vacuum pump means and said valve means so that fluid drawn therein separates into a liquid phase and a gas phase to remove entrained gas from said fluid when said valve means is in said first position.