Confirm whether the appearance changed

Use earlier evidence or an approved assembly reference to distinguish a designed lip from newly displaced material. Identify whether protrusion is local, circumferential or associated with a changed joint gap. A single oblique photograph can exaggerate a normal edge. Do not assume that the amount visible outside the joint represents the amount remaining in its working position or establishes the internal contact condition.

Investigate the appropriate contributors

Trelleborg identifies extrusion and related seal symptoms with multiple possible contributing factors. The actual material, fluid, temperature, geometry and duty determine which questions are relevant. A visual symptom cannot independently identify excessive pressure or a failed compound. Where the component contains pressure or stored mechanical energy, examination must follow qualified isolation and access procedures; external appearance does not establish that touching it is safe.

A protrusion can coincide with another changed dimension, such as an uneven joint opening. The reviewer should consider those observations together, because replacing only the visible sealing material may not resolve a geometry or loading issue that displaced it initially.

Choose correction rather than concealment

Ask the responsible specialist whether the seal is in its intended position, what mechanism needs investigation and what replacement or assembly assessment is appropriate. Do not trim, glue or force it back as a cosmetic correction. No MARSTON seal arrangement or pressure capability is assumed. The decision should address both the displaced material and the integrity of the sealing function, using the applicable equipment evidence.