Final answer:
In steel tube pile operations, employees must be out of the line of fire and wear appropriate PPE during the blowing out process to ensure safety.
Step-by-step explanation:
When steel tube piles are being "blown out", employees must be out of the line of fire. This safety precaution is crucial during the process of clearing blockages from steel tube piles where high-pressure air or water is used to eject material that may be causing an obstruction. Employees should be positioned in a safe location to avoid being hit by any debris or discharges that result from the blowing out operation. Additionally, appropriate personal protective equipment (PPE) such as hard hats, safety glasses, and hearing protection must be worn to provide further safety measures against potential hazards.