Alternative metallic seals

A seal assembly comprising:

• a first member which includes a bore;
• a second member which is received within the bore;
• a sealing surface which is located on at least one of the bore and the second member;
• a metallic sealing element which comprises in an unenergized state a generally tubular cylindrical body having first and second opposed ends and a center section located between the first and second ends;
• the tubular cylindrical body comprising a length defined between the first and second ends and a wall having a wall thickness;
• the ratio of the length to the wall thickness being greater than about 4;
• the sealing element in use being compressible so as to bring the first and second ends towards one another and thereby cause the center section to bulge transversely of the tube and sealingly engage the sealing surface;
• a first face which is formed on one of the first and second members;
• a second face which is formed on one of the first and second members and which opposes the first face;
• the first and second faces each being adapted to engage a corresponding first or second end of the tubular cylindrical body;
• wherein relative movement of the first and second faces towards each other causes the bulging of the center section of the tubular cylindrical body.

A metallic sealing element comprising:

• first and second opposed ends and a hollow center section which is located between the first and second ends;
• the center section comprising inner and outer walls each having a bellows-shaped cross-section;
• wherein in use the first and second ends are movable relatively towards one another to cause the inner and outer walls to bulge and sealingly engage a co-operating sealing surface;
• and
• a relatively easily deformable, relatively incompressible substance disposed in the hollow center section.

A seal assembly comprising:

• a first member which includes a bore;
• a second member which is received within the bore;
• a sealing surface which is located on at least one of the bore and the second member;
• a metallic sealing element which comprises first and second opposed ends and a hollow center section which is located between the first and second ends;
• the center section comprising inner and outer walls each having a bellows-shaped cross-section;
• wherein in use the first and second ends are movable relatively towards one another to cause the inner and outer walls to bulge and sealingly engage the sealing surface;
• a first face which is formed on one of the first and second members;
• a second face which is formed on one of the first and second members and which opposes the first face;
• the first and second faces each being adapted to engage a corresponding first or second end of the sealing element;
• wherein relative movement of the faces towards each other causes the bulging of the center section of the sealing element;
• and
• a relatively easily deformable, relatively incompressible substance disposed in the hollow center section.