ABOUT TORQUE HEADS

A screw-pile comprises a circular hollow section of steel shaft with one or more helical plates welded near to the end of it. The size of the shaft (diameter, wall thickness and length), combined with the size and placement of the helical plate are Engineer designed to take full advantage of the available soil capacity. Screw-piles are screwed into the ground like a self-tapping screw using rotary hydraulics, namely DIGGA SCREW/ANCHOR DRIVES, attached to earthmoving equipment to a specified torque capacity and a depth as directed by a certified foundation engineer.

Digga torque head unit's output torque is used to screw the pile into the ground. As the anchor reaches the desired compression torque or depth the operator stops. At this point the pile (or anchor) is under load.

When the operator stops, the load is trying to spin the pile backwards. While the anchor is only tensioned to say a ¼ or ½ a turn when it releases it does so in under 1/10 of a second. This motion can have dire effects on both the gearbox and the motor as it sends reverse energy back up into the drive unit. This motion effectively turns the reduction gearbox into a multiplier, essentially turning the hydraulic motor into a pump.

Swoosh Control (ECV) was designed to relieve the kick/flick back motion of the pile on the drive head. Basically, it prevents a pile of kickback/flick back by controlling the release of oil to the low-pressure side of the motor. The added benefit of the design is that it does not reduce the power available to the drive when the drive is installing the anchor. Its name came about as when the valve is working you can hear the controlled release of oil. A very gentle Swooossshhhhh... sound is heard.

Swoosh (ECV) is required for all drives used installing screw piles from PD4HF – PD50 to maintain a full gearbox and motor warranty (3yr Gearbox & 2yr Motor).

Should you be installing screw piles with a torque requirement up to 16,000Nm (12,000Ft/Lbs.) and do not have an ECV fitted you will have limited warranty (2yr Gearbox & 1yr Motor).

Using drive units without ECV for installing screw piles with an installation torque requirement of greater than 16,000Nm (12,000Ft/Lbs.) will have NO WARRANTY for Gearbox or Motor.

This will be determined by the maximum torque requirement of the specific screw piles that will be installed at the site in question. This in turn will be specified by the foundation engineer who has designed and designated the exact dimension, installation and torque requirement for this job site.

This will be determined by the maximum torque requirement of the specific screw piles that will be installed at the site in question. This in turn will be specified by the foundation engineer who has designed and designated the exact dimension, installation and torque requirement for this job site.

Dependent on the available flow and pressure available from the parent machine there will be a variation in the RPM speed of a smaller drive to a larger drive.

e.g. With the same parent machine with flow 200Lpm fitted with a SD45 would have 17 RPM at max torque, as opposed to same machine with same flow fitted with a SD95 would have 8 RPM at max torque. So, a definite flow decrease the larger the drive.

It is worth noting, speed (RPM) is dependent on Flow (LPM or GPM). Power (Nm or Ft/Lbs.) depends on pressure (BAR or PSI).

Yes, all drives are capable of use in screw piling and as an auger drive. Larger drives with higher torques will be limited by the RPM that will satisfy your drilling requirements.

Yes, but the size of the screw pile would be limited by the amount of torque required so that the machine is not compromised and is not at risk of boom failure or machine tipping. Best to confirm with the parent machine supplier of the safety factors for the machine in question.