To pull tubes using a tube puller and spears, one of the first steps is to “set” the spear in the tube. This process is done by threading the spear into the tube ID with an impact wrench or by hand.
The best way to “set” a tube spear to gain the most spear longevity and productivity is to:
Use a nickel-based anti-seize compound on the spear’s gripping teeth (thread). Nickel-based compounds protect metal-to-metal applications from seizing and galling under heavy loads. It is safe to use on both ferrous and non-ferrous metals. Without it, removing the pulled tube from the spear is very difficult and will slow production.
Set the spear with an industrial grade impact wrench that has adequate power to drive the spear to its set point. Using too small of an impact wrench can cause damage to the tube pulling threads as the spear will stop threading into the tube. The impact will cause vibration and damage to the spear’s gripping teeth and dramatically shorten its life.
Once the spear is driven to its set point, backing the spear ½ to ¾ of a revolution will reduce the stress on the spear’s gripping teeth and allow for easier removal of the spear from the tube after the tube has been pulled from the tube sheet. Be careful not to set the spear too deep, as this will cause difficulty in extracting the tubes.
From this point on, follow the operating instructions in the technical manual of the tube puller in order to pull tubes. Then repeat this process for each pulled tube.
Never stand behind the tube pulling ram when employed. Any recoil from the tube breaking free of the tube sheet or tool failure may cause severe injury to the operator.
For more information on tube pulling and spears, contact your local support or Elliott Tool Technologies.