English to Italian Tech/Engineering Petroleum Eng/Sci reactors

This has something to do with opening (cutting, drilling or otherwise breaking in) in process piping systems in a refinery or otherwise petroleum-related plants:
"Equipment Clearing AND PREPARATION

6.1. Wherever possible, prior to Process Equipment Opening, all in service equipment shall be emptied of its contents, flushed clean, and/or purged in accordance with site procedures.

6.2. Site procedures shall specify that equipment clearing/preparation be conducted to such a degree as to:
Eliminate the need for specialized Personal Protective Equipment (PPE) whenever possible; or
Reduce/minimize the level of specialized PPE that is needed to perform the task.

6.3. Appropriate safety precautions shall be used for Process Equipment Opening which previously contained hazardous materials, such as pyrophoric material, toxic, or corrosive materials.

6.4. Site procedures for equipment preparation shall address the following:
Isolation from energy sources, including mechanical, electrical, hydraulic, pneumatic, chemical, radiation, or thermal sources;
Depressurizing – venting to a closed/captive system is preferred. Atmospheric venting procedures shall consider vent location, proximity of other work activities, air monitoring, control of exposure to personnel, environmental requirements, etc.;
Draining – draining to a closed/captive system is preferred. Open draining procedures shall consider location, proximity of other work activities, control of exposure to personnel, environmental requirements, etc.;
Flushing/Purging – displacing the process materials with nitrogen, steam, etc.;
Cleaning – using steam, chemical washing, etc."