Ramsay grease is a

vacuum grease Vacuum grease is a lubricant with low volatility and is used for applications in low pressure environments. Lubricants with higher volatility would evaporate, causing two problems: * They would not be present to provide lubrication. * They would m ...

, used as a lubrication and a

sealant Sealant is a substance used to block the passage of fluids through openings in materials, a type of mechanical seal. In building construction ''sealant'' is sometimes synonymous with ''caulking'' and also serve the purposes of blocking dust, s ...

ground glass joint Ground glass joints are used in laboratories to quickly and easily fit leak-tight apparatus together from interchangeable commonly available parts. For example, a round bottom flask, Liebig condenser, and oil bubbler with ground glass joints may ...

s and cocks on

laboratory glassware Laboratory glassware refers to a variety of equipment used in scientific work, and traditionally made of glass. Glass can be blown, bent, cut, molded, and formed into many sizes and shapes, and is therefore common in chemistry, biology, and anal ...

, e.g.

burette A burette is a graduated glass tube with a tap at one end, for delivering known volumes of a liquid, especially in Titration, titrations. It is a long, graduated glass tube, with a stopcock at its lower end and a tapered capillary tube at the stop ...

s. It is usable to about 10⁻² mbar (about 1 Pa) and about 30 °C. Its

vapor pressure Vapor pressure (or vapour pressure in English-speaking countries other than the US; see spelling differences) or equilibrium vapor pressure is defined as the pressure exerted by a vapor in thermodynamic equilibrium with its condensed phases ...

at 20 °C is about 10⁻⁴ mbar (0.01 Pa). It is named after Sir

William Ramsay Sir William Ramsay (; 2 October 1852 – 23 July 1916) was a Scottish chemist who discovered the noble gases and received the Nobel Prize in Chemistry in 1904 "in recognition of his services in the discovery of the inert gaseous element ...

. Different grades exist (e.g. thick or viscous, soft). The viscous one is used for standard stopcocks and ground joints. The soft grade is for large stopcocks and ground joints,

desiccator Desiccators are sealable enclosures containing desiccants used for preserving moisture-sensitive items such as cobalt chloride paper for another use. A common use for desiccators is to protect chemicals which are hygroscopic or which react with w ...

s, and for lower temperature use. Ramsay grease consists of

paraffin wax Paraffin wax (or petroleum wax) is a soft colorless solid derived from petroleum, coal, or oil shale that consists of a mixture of hydrocarbon molecules containing between 20 and 40 carbon atoms. It is solid at room temperature and begins to m ...

petroleum jelly Petroleum jelly, petrolatum, white petrolatum, soft paraffin, or multi-hydrocarbon, CAS number 8009-03-8, is a semi-solid mixture of hydrocarbons (with carbon numbers mainly higher than 25), originally promoted as a topical ointment for its h ...

, and crude

natural rubber Rubber, also called India rubber, latex, Amazonian rubber, ''caucho'', or ''caoutchouc'', as initially produced, consists of polymers of the organic compound isoprene, with minor impurities of other organic compounds. Thailand, Malaysia, and ...

, in ratio 1:3:7 to 1:8:16. Due to the rubber content it has less tendency to flow. One recipe for a grease usable up to 25 °C consists of 6 parts of petroleum jelly, 1 part of paraffin wax, and 6 parts of Pará rubber. The

dropping point The dropping point of a lubricating grease is an indication of the heat resistance of the grease and is the temperature at which it passes from a semi-solid to a liquid state under specific test conditions. It is dependent on the type of thickener ...

of Leybold-brand Ramsay grease is 56 °C; its maximum service temperature is 25-30 °C. Its vapor pressure at 25 °C is 10⁻⁷ torr (0.013 mPa), at 38 °C it is 10⁻⁴ torr (13 mPa). An equivalent of Ramsay grease can be made by cooking

lanolin Lanolin (from Latin 'wool', and 'oil'), also called wool yolk, wool wax, or wool grease, is a wax secreted by the sebaceous glands of wool-bearing animals. Lanolin used by humans comes from domestic sheep breeds that are raised specifically fo ...

with natural rubber extracted from

golf ball A golf ball is a special ball designed to be used in the game of golf. Under the rules of golf, a golf ball has a mass no more than , has a diameter not less than , and performs within specified velocity, distance, and symmetry limits. Like g ...

References

{{Reflist Greases Vacuum systems Lubricants