YSJ TYPE Z OIL JAR

Working principle 

As the piston in the jar slowly moves up the cylinder, the working fluid (hydraulic oil) is pressured and compressed due to its slow out flowing rate. During this hydraulic time delay, elastic potential energy starts to accumulate in the drill tool. When the piston reaches the releasing bore, the hydraulic oil gushes out releasing the pressure, giving the piston a rapid upward load and releasing the elastic potential energy in the drill tool. When the jar pad hits the bottom of the up jar cylinder it creates an impact, this strong dynamic load is then transmitted to release the stuck drill tool. An important feature of this jar is the ease of closing  and resetting the tools for consecutive jarring.