Abstract: A vent, preferably made of metal, comprises a body (10) having an aperture (24) for the passage of a fluid and a sealing surface (11) surrounding the aperture. A porous membrane (50) lies against the sealing surface (11) and covers the aperture (24). A clamp arrangement may comprise a spring (30) pressing the membrane against the sealing surface (11) to prevent liquid from passing through between the sealing surface (11) and the membrane (50), e.g. by means of a cap (40) secured to the body (10) of the vent. The clamp arrangement is such that upon a reduction of the membrane thickness by 50% in the clamping area the compressive force per unit area does not change by more than 50%.

Abstract: A vent, preferably made of metal, comprises a body (10) having an aperture (24) for the passage of a fluid and a sealing surface (11) surrounding the aperture. A porous membrane (50) lies against the sealing surface (11) and covers the aperture (24). A clamp arrangement may comprise a spring (30) pressing the membrane against the sealing surface (11) to prevent liquid from passing through between the sealing surface (11) and the membrane (50), e.g. by means of a cap (40) secured to the body (10) of the vent. The clamp arrangement is such that upon a reduction of the membrane thickness by 50% in the clamping area the compressive force per unit area does not change by more than 50%.