An improved support structure for a valve stem positioned within a valve passageway of an HVAC line set quick connector is disclosed herein. The support structure may include a ring-shaped portion, a plurality of angled legs extending peripherally away and below the ring-shaped portion, and a plurality of terminal portions. The ring-shaped portion may be configured to surround the valve stem. Each of the plurality of terminal portions may be coupled to one of the plurality of legs and may further include an arcuate surface configured to engage the valve passageway of the HVAC line set quick connect. The improved support structure is configured to increase a cross-sectional opening area through the support structure such that coolant flowing through the HVAC line set quick connector is not substantially restricted.