De-isolation and Returning the Tank to Service
There are specific OSHA provisions for de-isolation and returning a tank to service. However, it is necessary to know the definition of "isolation" for tanks. The definition provided by OSHA includes: Confined Space safety procedures for inspecting an isolated tank to be returned to service, as well as the perimeter around the location of tank. Other requirements include:
- Documentation of tank integrity
- Completion of tank system verification
- Permit for reuse
- Municipal, state or federal variance to return tank to service
The Basics of De-isolation and Returning the Tank to ServiceIt is of considerable importance to retrieve all prior documentation of degassing procedures, tank inspections, repair and maintenance. This is crucial data for a facility operator who has purchased property where a tank is located that has not been in use for a long period of time. If the new owner of the property intends to de-isolate and return the tank to service, contact information regarding compliance and maintenance is found on these prior documents. In the case of an abandoned tank where no prior records exist, the property owner will be required to perform an inspection of tank integrity and serviceability, a plan of worker safety for de-isolation procedures, type of startup and lock out/tag out equipment and systems and specifications for degassing, such as methodology and equipment. Only after all regulations for isolated tanks have been complied with will federal and state agencies issue approval for return to service.
Worker Safety during De-isolation ProcessAll facility managers are required to provide worker safety during phases of degassing and de-isolation. This includes work inside the tank, as well as outside the tank. OSHA provides several guidelines that include:
- ANSI/API Standard 2015, Requirements for Safe Entry and Cleaning of Petroleum Storage Tanks (August 2001).
- ANSI/API Recommended Practice 2016, Guidelines and Procedures for Entering and Cleaning Petroleum Storage Tanks, First Edition, (August 2001).
- NFPA 326 – Standard for the Safe Guarding of Tanks and Containers for Entry, Cleaning or Repair.