Safety considerations and requirements for equipment retired from service but not removed and left abandoned in place.
Equipment that is being retired from service must be isolated from operating equipment, emptied of all chemicals or process fluids, de-contaminated and de-energized. The best decision is to entirely remove this equipment to keep it from rusting and deteriorating but this is not always possible and it becomes abandoned in place. If the equipment is abandoned in place it should be inspected periodically to ensure that it does not create a safety or environmental hazard. Inspections of equipment that is abandoned in place should look for signs of damage, corrosion, or leakage. Special attention must be paid to block valves, blinds, and other devices that isolate the abandoned in place equipment. The Operations Manager where the abandoned equipment resides should be responsible for having an updated list and make sure that the required inspections are being performed on a scheduled basis. He or she should be responsible to make sure that when capital or cost projects are performed in the area, the obsolete / retired from service equipment is removed as part of the D&R scope and hold the project team accountable before it is completed.
Obsolete / Abandoned In Place: Equipment that is permanently shutdown with no intention of restarting in the future. An analysis must ensure that if the process is partially dismantled, equipment is thoroughly de-inventoried (including heels) and cleaned so it can be safely removed.
D&R: Dismantle and removal
Idle equipment: A temporary or short-term shutdown that is not part of normal operations (e.g., campaigning process equipment), with the clear intent of re-start a date in the not-too-distant future. Measures should be in place to document or prevent equipment from being removed and that personnel retraining is adequate before starting back up.
- Cold Idle: All hazardous materials and utilities shutdown and properly isolated or de-inventoried (i.e., no steam, nitrogen, air)
- Hot Idle: Hazardous material storage and utilities remain active
Mothball equipment/ Facilities: A longer-term shutdown during which the capability of restarting the equipment at some point in the future is preserved, even though there are no firm plans or time frame in place for doing so. Restart will require a PSSR evaluation that all equipment is still fit for service, operating and maintenance procedures are still accurate and in place, and that personnel have had appropriate training. All hazardous materials and utility services are typically removed or fully shutdown.
All abandoned in place equipment should be properly isolated from process, utilities, energy sources and decontaminated at the time it was retired from service. In order to confirm that, before a D&R attempt is made the following verification should be completed.
- Process piping systems have been physically disconnected
- Make sure that all utilities (brine, instrument air, breathing air, steam, all waters, nitrogen, deluge systems, etc) have been disconnected
- Electrical power sources and fuses from motor control centers have been removed
- Electrical or steam tracing systems have been properly isolated
- Open equipment inspection ports/nozzles for internal inspection to verify that all residual chemicals were removed and all process vessels, storage tanks, receivers, pumps, piping systems, etc. were properly flushed
- Low point equipment, piping system, jackets and coils drains are opened and no evidence of chemical leak is present
Prior to starting the D&R process of the abandoned in place equipment the person responsible for the D&R process should consult a knowledgeable/competent area person and conduct an assessment including field verification to establish background information. The following questions should be used as a guide to gather the proper information.
- Identify the chemicals or process fluids in contact with the equipment being D&R and their respective health and physical hazards
- How and when was the equipment idled, mothballed, decontaminated?
- Is the equipment considered "clean"?
- What methods/test will be needed to determine the state of decontamination?
- What is the current operating/energized state of the equipment? Is it isolated from pressurized/energized sources (electrical, service, process, etc.)?
- Is the weight of equipment known?
- What method will be used to distinguish between equipment to be removed and equipment to remain?
- Will access into the area by those not involved in the D&R be required, if so, what routes will they use and what protection will be required for them?
- Will confined space entry be necessary?
- Is there a possibility of ground/soil/water/air contamination?
- Are there any asbestos-containing materials (>1%) in insulation, transite, roof flashings, etc?
- Are there any coatings containing lead?
- Is there any PCBs or Mercury containing equipment (lighting ballast, lighting tubes, electrical equipment and instrumentation)?
- What is the general structural condition? Is it deteriorated and will it break apart when lifted?
- Are there any overhead electrical conductors in close proximity or proximity to other structures not being D&R?
- Are there any Federal, State and perhaps, local regulations, which either govern D&R activity or, because of materials involved, must be complied with?
Once the field assessment has been conducted, a preliminary plan should be developed by the person responsible for the D&R activities. The plan should be laid out step by step and encompass every activity of the project with particular attention on the safety of D&R crew, other employees and the potential environmental / process impact.
If any remaining contamination is discovered while removing the equipment it must be decontaminated before it is placed on a scrap yard or transported off site.