API RP 5A3-F Recommended Practice on Thread Compounds for Casing, Tubing and Line Pipe – Application/Adherence Test
Thread compounds seal joints where pipes meet, such as in pipelines, casings, tubing and drill stems. Because many of these applications are on or under the ground for many years, the thread compound needs to give proper coverage on application and adhere to the threads for the lifetime of the piping. Additionally, outdoor assembly of these pipe structures occurs in all kinds of weather, including environments both on land and at sea. This test determines the application and adherence properties of thread compounds when applied at low temperatures often seen in northern latitudes and at high temperatures seen in tropical areas.
To test cold temperature application and adherence: the thread compound, application brush and pipe are brought to the cold test temperature (-7°C) and given time to stabilize. The thread compound is brushed on to the pipe and the brush-ability is observed. Reported are observations of layer uniformity, adhesion, and the formation of agglomerations or voids.
To test elevated temperature application and adherence: a weighed amount of thread compound is applied to pipe threads to provide a uniform thickness. The pipe is maintained at the test temperature (66°C) for the test time (12 to 17 hours), allowed to cool to room temperature and reweighed. Reported is the mass loss of thread compound at the elevated temperature and observations of uniformity, adhesion, and the formation of voids or agglomerations.