10.4 Solution

The multiple failures within a short period of time was a strong indication of an age related failure, as opposed to a random failure. As a result, several actions were taken:


Due to the potentially high consequence of production loss from this failure, other components of the HPU were also scrutinized. Other critical components, and possible single points of failure, were identified. These were parked for future improvements for the next asset refresh cycle. A similar exercise to this would be to perform a failure mode, effects and criticality analysis.

To ensure these upgrades were implemented in the next possible opportunity, the equipment upgrade was parked into the refinery's 5-year CAPEX plan. The site's


#### Table 2.

Typical aging damage mechanism (HSE UK RR823 Plant Aging Study) [13].

were estimated to be 10 years old. Aging was attributed as the cause of the problem, as within 6 months, another slide valve HPU had also suffered from an almost

There are several failure mechanisms that are typically found due to aging. Unfortunately, a detail inspection of the power supply unit was not carried out to identify the aging mechanism. Table 2 shows common aging mechanism for primary containment (piping, vessels, heat exchangers), structures, safeguarding systems and electrical, control and instrumentation (EC&I) [HSE UK RR823 Plant

The multiple failures within a short period of time was a strong indication of an age related failure, as opposed to a random failure. As a result, several actions were

• A Preventive Maintenance (PM) plan was created in PMMS to replace the

• Learnings (failure mode, failure mechanism, failure rectification) were incorporated into the technician training program for future ease of

Due to the potentially high consequence of production loss from this failure, other components of the HPU were also scrutinized. Other critical components, and possible single points of failure, were identified. These were parked for future improvements for the next asset refresh cycle. A similar exercise to this would be to

To ensure these upgrades were implemented in the next possible opportunity, the equipment upgrade was parked into the refinery's 5-year CAPEX plan. The site's

• All HPUs with PSU of similar make and type were identified.

• PSUs were replaced (like-for-like replacement).

perform a failure mode, effects and criticality analysis.

Typical aging damage mechanism (HSE UK RR823 Plant Aging Study) [13].

similar problem.

Maintenance Management

Aging Study] [8].

PSUs every 8 years.

troubleshooting.

10.4 Solution

taken:

Table 2.

74

Equipment Obsolescence Masterplan was also updated. This is typically reviewed on a yearly basis to manage overall life cycle of aging EC&I assets. Figure 12 is an example of an equipment obsolescence dashboard which lists EC&I equipment asset, obsolescence status and remedial plan.

This case study highlights several important aspects of managing aging assets:


Figure 12. Example of an equipment obsolescence dashboard (HSE UK KP4 report) [7].

analysis (FMECA), reliability availability and maintainability (RAM) analysis, and even layers of protection analysis (LOPA), among others. Each methodology puts a different focus on equipment reliability and integrity.

• The human aspect of managing aging asset should not be under-estimated. Knowledge is lost when people move or retire. Therefore, knowledge retention is key in ensuring assets can continue to be managed safely and reliably.
