Definition of gap seal here : https://glossar.item24.com/en/glossary-index/article/item//g...

Illustration below. The length of housing protruding along the shaft can conceal different kinds of 'gap seals': simple clearance seals, oil-groove seals and labyrinth seals of different kinds.

A gap seal is a 'joint sans contact':

"Joints sans contact
Les joints sans contact peuvent être divisés en trois catégories distinctes : les joints à fente, les labyrinthes traditionnels ou les labyrinthes composés, souvent appelés Isolateurs de palier. Les JOINTS À INTERSTICE, ou à jeu, offrent au mieux une protection minimale, car ils reposent uniquement sur un interstice ou un faible écartement comme mécanisme d'étanchéité pour bloquer tout ce qui est plus grand que l'interstice."

See description and illustration below. Details of types of 'joint sans contact' here: https://www.nskeurope.fr/content/dam/nskcmsr/downloads/liter...

Note therefore that a 'joint à interstice' is but one kind of 'joint sans contact'.

In English there is some confusion and overlap between 'gap seal' and 'clearance seal'. After all, gap and clearance mean the same thing, and many people use 'clearance seal' when they are really referring to the different kinds of gap seals (of which a clearance seal is one).

"Clearance Seal: A seal which limits the leakage between a rotating or reciprocating shaft and a stationary housing by mean of a controlled annular clearance between the two." [see illustration]


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Note added at 22 hrs (2022-05-22 14:51:46 GMT)
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