Challenge and Opportunity
Chronic failures of a coalescer pressure vessel plagued a major chemical manufacturing facility. The production critical pressure vessel experienced 116 failures in 2011-2012 and cost $300,000 in maintenance to replace constantly plugging filter elements. Additionally, a poor MTBF of three-five days for 10 years since the original installation had cost the company millions in maintenance costs and production losses.
But the problem wasn’t viewed as an obvious, large impact item equipment failure. The culprit turned out to be a low impact, but high frequency failure. Chronic failure use a lot of man power, but may not always cost significant cumulative maintenance dollars. Also, due to their repeated occurrence, they might give a false appearance of being the “norm” or part of the require maintenance.
An investment of $200,000 eliminated chronic pressure vessel failures, and increased availability that saved $250,000 per year in maintenance costs and another $400,000 per year in production losses. The solution implemented by the chemical manufacturing company consisted of asset-level benchmarking using Meridium Asset Answers.
They started by comparing their operational experience against other chemical companies They learned the following:
• They experienced 2X as many failures as their peers, with a Mean Time between Failures (MTBF) of 93 months for all types of assets.
• If MTBF could be increased to a peer average of 220 months, the reduction in failures could save about $51 million ($26 million/year) in maintenance costs alone.
• Analyzing the asset performance by equipment taxonomy, the equipment class of “Vessel” in fixed equipment category has the maximum opportunity for cost savings.
• This company’s vessels fail almost 6X more often than industry peers, with an MTBF of 18 months.
• Reducing failures and increasing MTBF of vessels to peer value of 113 months, they could save $11 million ($6 million/year) in maintenance costs.
• Adding more detail to the equipment taxonomy, of the type “Pressurized Vessels,” showed a MTBF of 2 months compared to a peer MTBF of 13 months, an opportunity to save $4 Million ($2 million/year).
A Root Cause Failure Analysis (RCFA) was undertaken using the PROACT (Preserve, Order, Analyze, Communicate and Track) methodology. It identified the main reason behind these frequent filter plugs as the accumulation of emulsion on the filter surface. Once fully understood, a high pressure backwash system was installed to remove the residue left on the filter after the coalescence operation.
Based on historical work order between 2011-2012, Asset Answers automatically calculated that this company spends an average of $20,000 per month in maintenance and $32,000 per month in lost production. After installing the filter backwash system, the predicted maintenance cost will go down to $500 per month with no production losses.