Fluid drain system for filter chamber access in heat rejection unit

A system comprising:

• a liquid-to-air heat rejection unit (HRU) that receives and circulates a liquid coolant during nominal operations, the liquid-to-air HRU including a filter chamber assembly that includes a drain valve plug for releasing fluid from an interior of the filter chamber assembly;
• and
• a fluid containment apparatus comprising:
• a drain valve receptacle with a first end configured to mate with the drain valve plug;
• a syringe including a vial and a plunger;
• and
• tubing that fluidly couples the drain valve receptacle to a vial of a syringe such that actuating the plunger of the syringe away from the vial while the drain valve receptacle is mated with the drain valve plug on the filter chamber assembly draws the liquid coolant from the interior of the filter chamber assembly into the vial.

A method for changing a component within a filter chamber assembly of a liquid-to-air Heat Rejection Unit (HRU), the method comprising:

• closing an isolation valve in-line within the filter chamber assembly to isolate a filter chamber of the liquid-to-air HRU from an upstream portion of a coolant loop that circulates a liquid coolant;
• subsequent to closing the isolation valve, creating a liquid-tight coupling between a fluid containment apparatus and the filter chamber of the liquid-to-air HRU by attaching a first drain valve component on the fluid containment apparatus to a second drain valve component on the filter chamber, the fluid containment apparatus including a syringe attached to the second drain valve component via tubing;
• while the first drain valve component is coupled to the second drain valve component, actuating a plunger of the fluid containment apparatus to drain the filter chamber by drawing the liquid coolant from the filter chamber into a vial of the fluid containment apparatus;
• while the liquid coolant from the filter chamber is contained in the vial, servicing a component within the filter chamber assembly;
• and
• subsequent to servicing the component, actuating the plunger of the fluid containment apparatus toward the vial to reinject the liquid coolant into the filter chamber assembly.