The Forgotten Capital Spares

May 26, 2020 10:45 am || || Categorized in:

Preservation Program

What are Capital Spares?

A Capital Spare is a piece of equipment, or a spare part, of significant cost that is maintained in inventory for use in the event that a similar piece of critical equipment fails or must be rebuilt.


What is the purpose of Capital Spares?

Minimize Downtime:
  1. Protect an organization from a major equipment failure that would result in a prolonged shutdown due to long lead times to get a replacement.
  2. Rotatable Spare Part – Held in inventory for extended periods of time to be used by one site, or shared between multiple sites, to replace an existing long-life piece of equipment that is scheduled for a major repair.
  3. Capital Spares are held in inventory and assumed to be in a fully functional and 100% reliable condition.


How can Capital Spares provide a false sense of security?

Equipment “Infant Mortality” Failure:
  • Newly installed Capital Spare fails. Why? The Capital Spare that was held in inventory for several years was not properly preserved and not maintained.
Not Ready for Use:
  • Prior to installing the Capital Spare, an inspection reveals damage that requires repairs prior to placing the equipment in service.


Why establish a Preservation Program?

  1. Capital Spares must be protected against moisture, debris, and other damaging environmental conditions to ensure they are maintained in a fully functional and 100% reliable condition.
  2. Routine maintenance tasks should be performed to inspect for damage and verify bearings, shafts, gears, casings, motors, etc. are maintained in a fully functional status.
  3. A Preservation Program can also be used for critical spare parts and critical idle equipment that is not maintained as a Capital Spare.


machinepart1 machinepart2
No Preservation Program Preservation Program


What should you do with your “forgotten” Capital Spares?

Establish a Preservation Program:

1. Every Capital Spare should be tagged and entered into a documented Preservation Program.

2. Categorize Capital Spares by type of equipment, anticipated time the equipment will remain in storage, and the time that will be required to return the equipment to service.

3. Document the preservation tasks that are performed when a Capital Spare is placed into and removed from inventory.

Conduct Routine Maintenance:

1. Perform external and internal visual inspections for damage.

2. Rotate shafts at least monthly.

3. Verify a protective coating has been applied to rotating exposed machined surfaces, shafts and couplings, and reapply as needed.

4. Confirm equipment is being stored under controlled environmental conditions, as required.

5. Inspect for rust, corrosion, or debris.

Examples of Capital Spares that will benefit from a Preservation Program:

  • All types of rotating equipment – gearboxes, pumps, motors, agitators, turbines, large fans, compressors
  • Electrical equipment – oil-filled transformers, switchgear
  • Electronic equipment – controllers, VFDs, sensors, analyzers


Examples of Preservation Program tasks that are performed:

  • Flush equipment oil reservoirs and gearboxes with a rust prevention treatment, such as Mobilarma 200 Series, and fill with oil to protect equipment and components during storage
  • Coat couplings (except elastomers) and external machined surfaces with corrosion-inhibiting material
  • Flush and drain pump housings
  • Rotate motor, turbine, compressor, pump, fan, agitator, and blower shafts at least monthly, 10-15 revolutions, to redistribute the lubricant
  • Coat casing bolts with corrosion-inhibiting material
  • Neutralize acid or caustic pumps
  • Liquid filled transformers with sealed tank – verify the tank is placed under a Nitrogen blanket and check monthly to ensure 2-3 psig Nitrogen pressure is maintained


What other items should be included in a Preservation Program?

  • Equipment that is removed from service temporarily
  • Stand-by, redundant equipment that is not routinely operated
  • Intermittently used equipment that is idle for extended periods of time
  • Low turnover spare parts that are not stored in controlled environmental conditions



About the Author

Robert Smith is a senior Asset Management & Reliability (AM&R) professional with 40+ years of engineering, maintenance, and project management experience including developing and managing asset management and M&R programs utilizing industry and global best practices and methodologies.