Metal C-rings are static sealing elements for machines and installations with high requirements. Metal C-rings are considerably more elastic than metal O-rings and other metal seals.
The prestressed forces are approx. At one third of the ones metal O-rings (compare diagram page 7). However these prestressed forces differentiate according to material, heat, tolerances, treatment etc.
The sealing is secured by means of the spring-back of the metal C-rings, as movements inside the flanged joint (in extreme case flange removal) have to be taken into account. The prestress / deformation is approx. a 20% of the ring height.
Metal C-rings are available for internal and external pressure or axial thrust. The seal operates self-energizing as the metal C-rings are open towards the thrust face. C-rings are available with a ring outside diameter from 6.5 mm to 300 mm as well with round profile section or also in special profiles. Dimensions from 0.9 mm to 6.4 mm are available as profile sections.
Available are the same materials and coatings as with O-rings. Inconel X-750 (= code no. 5) is the standard material of C-rings. Applications are possible in the range up to 980 degrees centigrade above zero. High-vacuum 10-10 mb l/s up to the ultrahigh pressure range of 6800 bar can be accomplished with metal C-rings.
Metal C-ring types
for internal pressure
for external pressure
for axial thrust and radial sealing
Metal C-ring for internal pressure
The outside diameter of the metal C-ring for internal pressure is accepted as reference dimension. The groove outside diameter is somewhat bigger than the ring outside diameter. Therefore the ring has to be somewhat smaller than the groove outside diameter.
Metal C-ring for external pressure
The inside diameter of the metal C-ring for external pressure is accepted as reference dimension. The groove inside diameter is somewhat smaller than the ring inside diameter. Therefore the ring inside diameter has to be somewhat bigger than the groove inside diameter.
Metal C-ring for axial thrust and radial sealing
The outside diameter of the metal C-ring for axial thrust and radial sealing is accepted as reference dimension. The radial sealing is effected by the C-ring between the inside and the outside diameter.
The correct dimension and quality of finish of the groove are as important as the metal C-ring itself for the use of the seal. The following listed recommend groove dimensions for internal and external pressure applications are to be understood as general recommendations for the preparation of sealing faces.
Recommended groove dimensions: outside and inside dia. are values incl. coating
Sealing specification and order code key
The order example described above „MCI-532-096,80-1S1“ refers to a metal C-ring for internal pressure of the type MCI of:
Inconel X-750, with free height of 2.4 mm, a wall thickness of 0.25 mm, a ring outside diameter of 96.80 mm (without plating thickness), conventional cold-hardened, silver coated with a coating thickness from 0.15 to 0.30.
Should you require any further instructions or recommendations, please supply us the following information:
application, ranges of temperature and pressure, available space, material, medium to be sealed, available force of pressure, drawing of the installation position.
Our competent and experienced team will always assist you consultative.