Designed to intensify the jarring action and cushion the force on the rope socket.
Run in tool string directly below the rope socket when jarring up. The spring is collapsed and when the hydraulic jars fire, the spring tension is released, accelerating the tool string upwards at a much higher rate of speed. This keeps the energy of the jarring force in the tool string and lessens the force on the line and rope socket.
Do not place vice jaws or pipe wrenches on the barrel where it can be crushed. Remove Cap Head Screws before attempting disassembly. Check for cracks or damaged parts when servicing.