API RP 5A3-G Recommended Practice on Thread Compounds for Casing, Tubing and Line Pipe – Gas Evolution Test
Thread compounds often contain thickeners including graphite and metals (lead, zinc, copper). If these components are reactive with one another or with other grease components, the grease may not be stable enough for long term underground use. This test measures gases produced when the thread compounds are heated for a specified time. The amount of gas produced is an indication of the long term stability of the thread compound.
The thread compound is placed in the test vessel and brought to the test temperature (66ºC). The amount of gas produced is periodically measured. The volume of evolved gas is reported in cubic centimeters.