Common Oil Resistant Rubber Valve Design Mistakes and How Product Teams Can Avoid Them

https://airbreathingparts.cavandoragh.org/what-buyers-should-know-before-ordering-a-custom-one-piece-valve

Designing a small part can affect the whole product. A oil resistant rubber 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