oil samples show dirty vs. clean oil

How to plan a successful oil flush

Finding time to prioritize and plan oil flushes is difficult. Unless there is a major outage, lube oil cleaning is usually relegated to just another line item on the turnaround to do list.

However, a little planning goes a long way. The success and impact of an oil flush can be greatly improved with a better plan, leading to higher amounts of contaminants removed and longer equipment life. The following steps will help you plan, execute and achieve oil flushing success:

Step One: Properly Vet and Hire the Right Flushing Experts

Not all flushing companies are equal. You should look for a company that can demonstrate expertise in the procedure to be performed, can provide plenty of references and testimonials upon request, and has a clear, communicable procedure. Go beyond talking to the salesperson to trying to understand how the technicians truly behave on a job site and the underlying culture of the company is. Are they people you want to work with? Do they seem trustworthy and have plenty of references who can verify they say what they do? For a full list of ways to properly vet a flushing contractor, checkout our guide to choosing a contractor.

Step Two: Normal Operation Walkdown and Detailed Plan Development

Your flushing contractor should absolutely come out to your facility during normal operation for a Walkdown. The walkdown not only gives them a chance to see normal plant operations and system expectations, but allows for development of a detailed flushing plan ahead of time. This plan should include written procedures, materials to bypass critical equipment, items the site supplies, items the contractor will supply, detailed steps, safety requirements, and most importantly the criteria used to execute the oil flush and deem the system clean. Deviations to procedures, safety data sheets, a spill prevention plan, emergency contact phone numbers and signature lines for approving the procedure should also be considered.

Step Three: Make Checklists to Double Check

Checklists for every system should be developed that help you and your contractor verify the system is ready for flushing. Things to run down include:

  • Remove any foreign material that could contaminate the system, such as different lubricants or rusty fittings,
  • Make sure there is a comprehensive foreign-material exclusion plan and confirm all materials to be used for the flush have performed adequately. Check for:
    • Pressure testing records for temporary hoses
    • Certificates of calibration for testing equipment
    • Flow charts for temporary pumps
    • Maintenance procedures
    • Get a thorough walk through of all standard operating procedures.

Step Four: Review Your Plan Against Best Practices

A few best practices to keep in mind:

  • Remember a flush is about flow not pressure. While turbulence can be reached at a Reynolds number as low as 4000, flushes done at that Reynolds number will often not sufficiently remove clinging debris. A flow number of 3-4 times that will often be required to full remove foreign materials from the system and not cause problems at system startup.
  • External temporary pumps or primary and redundant pump setups are best for achieving the high Reynolds numbers required for a good flush.
  • Coolers present a challenge in and of themselves. They potentially harbor dirt, decrease flow and cause delays. At a minimum, coolers should be flushed on a separate circuit to reduce the possibility of dirt collecting in them during the major flush. The best approach is to pull and clean them separately, if time allows.
  • A first pass or “course” flush should always be performed a minimum of 24 hours before any inspection media is used. For larger systems, initial flushes of 48-72 hours are recommended. Shutting down the system before these initial flushes complete is a huge waste of time and will only delay the overall project.
  • After the first course flush is complete, insert the inspection media at the farthest point away from the filter. Run the system at normal rates for one hour, then remove and inspect the media. This will tell you whether the course flush should continue or if the system is ready for inspection.
  • It is always prudent to know who all the decision makers are that need to be involved to eliminate delays. If the person signing off on system cleanliness is on vacation during the flush, it’s probably not going to be completed on time. Make sure all parties that have to be present to approve project stages are around and available as much as possible during the flush. Action items or problems could arise at anytime 24/7 during an active flushing procedure.

Step Five: Benchmark and Document for Future Efficiency 

Having your procedure well documented also means documenting all aspects of the flush. Logs for temperature, flow, pressure, filter life and work performed will help keep the project on track and point out any changes as you move along. We suggest keeping all these records in a flushing procedure document, so you have them for the next flush on that system, which will also help you benchmark and justify the need for current or future flushing activities.

A successful flush is more than a line item on another checklist. It is a well thought out procedure, customized to your equipment and executed by professionals with excellent project management approaches. A good plan is the starting point. Every flush will have some surprises, and being able to quickly see, adjust and adapt is key. If you are looking for an experienced partner for your next flush, please don’t hesitate to reach out to one of certified technicians to discuss your project today.

Source: Larry B. Jordan