What is a static seal?

• A. Lip seal
• B. O-ring
• C. Packing
• D. Gasket

Answer: (D)

Static sealing is about preventing leaks between two mating surfaces that do not move relative to one another. A gasket fits this role by being a deformable sheet or shaped material placed between the faces; when the joint is tightened, it’s compressed to fill gaps and irregularities, creating a seal without any sliding contact. That stationary interface is what makes a gasket the typical static seal.

In contrast, lip seals and O-rings are commonly used where movement occurs, relying on a flexible contour or ring to maintain contact as parts slide or rotate. Packing is a sealing method used around moving stems or shafts in stuffing boxes, where the material fills the gap while accommodating movement. Since this question focuses on a seal between stationary surfaces, the gasket is the best fit.