An annular seal (500, 600) having in a diametrical cross-section a first end portion (502, 602) having a distal end (504, 604), a second end portion (506, 606) and a central body portion (510, 610) that is between and contiguous with said first end portion (502, 602) and said second end portion (506, 606), said second end portion (506, 606) having an arcuate portion (507A, 607A) that curls in accordance with a predetermined radius in a first direction, that is in a radially outward direction, said central body portion (510, 610) having a first side (520, 640) and an opposite second side, wherein said annular seal (500, 600) further comprises in the diametrical cross-section: a linear portion (507C, 607C) that is contiguous with said arcuate portion (507A, 607A) and which has a length; a portion (507B, 607B) that is contiguous with said linear portion (507C, 607C) and which extends to a distal end (508, 608); wherein said distal end (508, 608) is located across from said first side (520, 640) of said central body portion (510, 610) by a predetermined distance; wherein said distal ends (504, 604) and (508, 608) do not face each other; wherein the length of said linear portion (507C, 607C) and the predetermined radius of arcuate portion (507A, 607A) determine the predetermined distance which separates said distal end (508, 608) from said first side (520, 640) of said central body portion (510, 610); and wherein said central body portion (510, 610) has a generally frusto-conical shape, wherein the central body portion (510, 610) is configured so that it does not have any inflection points formed therein; characterised in that the portion of said first end portion (502, 602) having said distal end (504, 604) is slightly angulated in said first direction with respect to a reference line formed by the frusto-conical shape of the central body portion, wherein the portion (507B, 607B) that is contiguous with said linear portion (507C, 607C) and which extends to a distal end (508, 608) slightly curls inward. a linear portion (507C, 607C) that is contiguous with said arcuate portion (507A, 607A) and which has a length; a portion (507B, 607B) that is contiguous with said linear portion (507C, 607C) and which extends to a distal end (508, 608); wherein said distal end (508, 608) is located across from said first side (520, 640) of said central body portion (510, 610) by a predetermined distance; wherein said distal ends (504, 604) and (508, 608) do not face each other; wherein the length of said linear portion (507C, 607C) and the predetermined radius of arcuate portion (507A, 607A) determine the predetermined distance which separates said distal end (508, 608) from said first side (520, 640) of said central body portion (510, 610); and wherein said central body portion (510, 610) has a generally frusto-conical shape, wherein the central body portion (510, 610) is configured so that it does not have any inflection points formed therein; characterised in that the portion of said first end portion (502, 602) having said distal end (504, 604) is slightly angulated in said first direction with respect to a reference line formed by the frusto-conical shape of the central body portion, wherein the portion (507B, 607B) that is contiguous with said linear portion (507C, 607C) and which extends to a distal end (508, 608) slightly curls inward.