An adapter for connecting components in a fluid system has an adapter body defining a cylindrical space and lock buttons which are biased into a locked position to secure the adapter to another component. The adapter body has a circular collar defining an inlet into the cylindrical space, a channel defining an outlet out of the cylindrical space, a support wall and a support flange defining one or more cutouts in an outer cylindrical side wall of the adapter body, and a slot defined between the collar and the support wall connecting the one or more cutouts to the cylindrical space. The lock buttons have a contact element positioned in one of the cutouts and an arm projecting positioned in the slot. The arms are partially in the cylindrical space in the locked position and are movable into an unlocked position when the contact elements are moved toward each other.