Dynamic O-rings have the same amount of squeeze as static O-rings?

Dynamic O-rings do not have the same amount of squeeze as static O-rings due to the different operating conditions they encounter. Squeeze refers to the amount the O-ring is compressed between two surfaces to create a seal.

In static applications, the O-ring is compressed while remaining stationary, which allows for a more consistent and uniform fit against the sealing surfaces. The design and installation ensure that the O-ring maintains adequate pressure without significant movement that could affect the seal.

In dynamic applications, however, the O-ring must accommodate motion—it may experience sliding or rolling action between surfaces. This movement can change the effective squeeze and can lead to a higher risk of extrusion or wear. Dynamic seals require different considerations in terms of material properties and design to manage the compression and the effects of motion, such as friction and potential heat, which can affect the seal's reliability and lifespan.

Understanding this difference is crucial for millwright work involving the selection and installation of O-rings to ensure proper sealing under various operating conditions.