A Clear Checklist for Planning a Successful Oil Resistant Rubber Valve Project

https://rubberdispensingblog.tearosediner.net/how-silicone-valve-seal-geometry-supports-stable-opening-pressure

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