GB718142A - Improvements in or relating to piston rings suitable for high-pressure oxygen compressors - Google Patents

Abstract

A piston ring suitable for a high-pressure oxygen compressor comprises a mixture of a natural graphite such as Bavarian or Ceylon, the dust of which cannot be ignited by oxygen compressed to pressures as high as 150 atmospheres at an initial temperature as high as 230 DEG C., as a lubricating component, and a binding agent which is at least as difficult to ignite as the lubricating component. The binding agents may be powdered metals, e.g. aluminium, copper, silver and mixtures or alloys, or non-metallic substances, e.g. oxides, sulphates and silicates such as talcum or gypsum. The mixture is compressed in a mould at over 1,000 kg. per cm.2 to form a complete ring or segments which may be soldered or cemented together. The moulded material may be sintered at a temperature below the melting point of the binding agent.ALSO:A piston ring suitable for a high-pressure oxygen compressor comprises a mixture of a natural graphite such as Bavarian or Ceylon, the dust of which cannot be ignited by oxygen compressed to pressures as high at 150 atmospheres at an initial temperature as high as 230 DEG C., as a lubricating component, and a binding agent which is at least as difficult to ignite as the lubricating component. The binding agents may be powdered metals, e.g. aluminium, copper, silver and mixtures or alloys, or nonmetallic substances, e.g. oxides, sulphates and silicates such as talcum or gypsum. The mixture is compressed in a mould at over 1,000 kg per cm2 to form a complete ring or segments which may be soldered or cemented together. The moulded material may be sintered at a temperature below the melting point of the binding agent.