Forming a seal between planar sealing surfaces

A sealing assembly for providing a seal between confronting planar sealing surfaces on two annular structural members which are drawn toward each other by securing means;

• said sealing assembly comprising:
• a toroidal, crushable seal member;
• a flat annular spacer member surrounding said toroidal, crushable seal member and defining an annular shoulder on the inner diameter thereof on which said toroidal, crushable seal member seats, said flat annular spacer member further defining a radially extending annular recess on its inner surface, and
• an annular resilient member seated in said annular recess and bearing against said toroidal, crushable seal member to center the toroidal, crushable seal member within the flat annular spacer member and resiliently lock the toroidal, crushable seal member against said shoulder while permitting the seal member to expand radially as it is crushed by the drawing of the planar surfaces on said structural members toward each other by the securing means, the thickness of said flat annular spacer member being less than that of said toroidal, crushable seal member to set the distance that the planar surfaces are drawn toward each other, and therefore provide uniform crushing of the toroidal, crushable seal member.

In a nuclear reactor, the combination of a generally, cylindrical pressure vessel having a flange extending radially around its upper end which defines an axially facing planar sealing surface and axially extending bores passing through said sealing surface, a substantially hemispherical head having a radially extending flange around its lower end which defines an axially facing planar sealing surface complementary to the sealing surface on the pressure vessel flange and which also defines axially extending bores aligned with the bores in the pressure vessel flange, bolts passing through the bores in the pressure vessel and head flanges to draw said flanges toward each other, and a sealing assembly comprising:

• a toroidal, crushable metallic, tubular seal member;
• a flat, annular spacer member defining a radially extending V-shaped annular recess in its inner surface and axially extending bores aligned with the bores in said pressure vessel and head flanges through which said bolts pass to position the spacer member relative to said flanges;
• and
• a toroidal coil spring seated in said V-shaped groove and sized to grip and position said toroidal, crushable metallic tubular seal member inside said flat annular spacer, said flat annular spacer being substantially rigid and axially thinner than said seal member such that as said bolts are tightened to draw said flanges toward each other and down against said spacer member, the seal member is crushed between said planar sealing surfaces to form a seal therebetween.