Purity Rings For Girls – Metal O-rings will be the metallic variations of typically used elastomeric O-rings. They are generally utilised in stationary sealing applications that are incompatible with all the chemical and physical characteristics of elastomeric O-rings. These O-rings have high tolerance to radiation as well as high vacuum, and are usually used for flanged applications. Ideally, metal O-rings are placed in both closed and open grooves and axial pressure is applied between two parallel surfaces. Furthermore, grooves that hold the O-rings are made to be perpendicular to the direction of the fluid stream. When placed between compressed and surfaces to a predetermined height, deforms and generates contact between the jointing and sealing faces. Inherently, O-rings’ metallic elasticity displays a affordable deflection and generates maximum sealing contacts through surgery to make sure the sealing action. In addition to elastic deflection of this alloy, structural assembles of this O-rings also play a significant role in creating the sealing force. Even though most metals may be used for fabricating metal O-rings, the option of metals should be such that the linear expansion co-efficient of this O-ring metal varies slightly from the linear expansion co-efficient of this alloy(s) of jointing surfaces. Metal O-rings are vulnerable to rust unlike elastomeric O-rings, and therefore, are coated with the right substance to avoid rusting. This material is softer than the base metal and serves another purpose of negating the impact of surface abnormalities. The coat materials that are ordinarily utilized are soft metals, such as silver, and non-metals such as PTFE.
Metal O-rings are primarily classified based on their fundamental structural attribute, they are classified as follows:
- Strong Metallic O-Rings
- Hollow Metal O-Rings
Strong Metallic O-Rings
Strong metal rings are wires of circular profile attached like a ring. These types of O-rings require specific grooves for their efficient performance. This requirement of specific grooves limits the use of solid metal O-rings to specific applications, such as engine cylinder heads. Strong metal rings are usually made in aluminum and appropriate for use in atomic reactors, for checking radiation flows. These O-rings can handle pressures of around 4MPa and temperatures reaching 500°C and are suitable for moderate pressure and moderate vacuum applications.
Hollow metal O-rings are structurally more sophisticated in comparison with good metal O-rings and formed by circular tubes bent to the form of a ring. These O-rings are sub-classified based on the qualities of the hollow sector of the ring.
These are hollow metal O-rings with nitrogen at atmospheric pressure or vacuum within them. Plain hollow O-rings are used in low pressure or low vacuum applications. Although plain hollow O-rings show similarity in pressure and temperature handling capabilities with good metal O-rings, they provide considerably superior spring-back and sealing capabilities. Generally, plain hollow metal O-rings are produced in Inconel 750 and garnished with silver.
Self Energized Hollow O-Rings:
Self-energized hollow O-rings have vents or holes in their surfaces to use the system pressure or atmospheric pressure for sealing action. Based on the orientation of these grooves, the O-rings are categorized into internally vented O-rings and externally vented O-rings. Internally vented O-rings made of light steel and garnished with PTFE can withstand pressures of around 3500 kg/sq cm and temperatures of 600°C. Externally vented O-rings are used in applications where the external pressure is higher than the pressure within the seal.
Pressure Filled Hollow Rings:
Pressure stuffed hollow O-rings are altered plain hollow rings with pressurized inert gasses inside them. These O-rings may be utilised in tongue and groove flanges and can handle temperatures from cryogenic temperatures up to 850°C. Pressure filled O-rings are used in vacuum sealing applications.
- Metal O-rings cannot be utilized in highly dynamic sealing applications
- These O-rings are rendered useless when they are used once because they cannot keep their shape after single use
- Broad tolerances of this groove cannot be adapted by the metal O-rings, especially in bigger sizes
- Careful fitting ought to be done in order to avoid their deformation until their seal is tightened.