In various examples, a hub for a medical device includes a hub housing including a passage from a proximal end of the hub housing to a distal end of the hub housing. A valve is disposed within the hub. The valve is configured to allow passage of an insertable device through the valve while inhibiting leakage of fluid from the valve. A cap is engaged to the hub housing. The cap includes an opening therethrough sized and shaped to allow passage of the insertable device through the opening. The opening allows access to the passage of the hub housing. An angled sidewall is disposed within the hub. The angled sidewall is configured to retain and deform the valve into a curved shape.