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NOV Mechanical Spring Jar

NOV Mechanical Spring Jar

The NOV Mechanical Spring Jar uses disc springs (belleville washers) to provide the resistance that tension applied by the winch from surface has to overcome to fire the jars. The force required to fire the jars is adjustable, however the adjustments must be made on surface prior to running the tool. The firing mechanism is based up on the ‘B’ shifting tool key principle using angled leading and trailing edges of the keys to release the jar rod and to re-set the tool for the next jarring cycle.