Common Liquid Dispensing Valve Design Mistakes and How Product Teams Can Avoid Them

https://rubbervalvelab.theglensecret.com/how-an-air-breathing-valve-helps-packaging-and-devices-manage-airflow

Designing a small part can affect the whole product. A liquid dispensing valve may look simple, but it has a real job to do. It must work with the cap, case, fluid, air path, or light path around it