Work experience at Merisol RSA (SASOL)
Implementation of Reliability Engineering in Merisol RSA
Reliability engineering is a relatively new concept in the field of engineering, despite this
reliability engineering is on an up rise in all environments. The importance of reliable
equipment has been acknowledge by top management and the implementation of reliability
programs and advanced maintenance strategies are now a priority.
The main purpose of this report is to inform the reader about the vital importance of reliability
engineering and to guide the reader in understanding reliability engineering. We will also
discuss some of the tools available, for example RCM, RCA and MTBF to help you reach
reliability in the plant environment. We will also look at Merisol in terms of reliability and the
status of equipment in terms of availability. This directly leads to the equipment uptime.
With a well-rounded reliability program in place, using the previously stated tools the following
improvements may be observed:
5-10% improvement in availability
10-20% decrease in maintenance costs
25-35% increase in equipment uptime.
Areas where reliability in Merisol was investigated;
1. Plant availability
2. Identifying critical equipment
3. Preventive maintenance
4. Predictive maintenance
5. Spare parts management
6. Skill enhancement
7. Equipment history
Recommendations on areas of improvements:
1. Set Plant availability goals
Operations, Maintenance and Technical must establish the availability goals for each
plant based on the required production targets and equipment utilisation.
To put perspective on your availability goals and current availability it is wise to group
together availability, capacity and utilisation.
2. Identify critical equipment
Update the procedure of identifying critical equipment. This ensures that equipment
that has a large impact on production does not slip through. Reliability Centred
Maintenance may reduce safety risks.
It is highly recommended to implement RCM `s.
3. Preventive/Predictive maintenance
Must move away from reactive maintenance which is a very expensive practise to
Predict failures with the aim of preventing them.
Equipment should receive condition monitoring - allows us to predict when equipment
will fail and prevent future failures. A life cycle analysis tool may be used. We will be
able measure the performance of equipment in terms of the amount of production time
Gear Ratios of new spares
New spares were ordered on a gearbox; the supplier changed the driver gear with no manual.
The driver gear has changed in size and amount of teeth. Both the old gears had the same
amount of teeth. How does the increase of size and amount of teeth of the driver gear effect
Rotating Equipment Preventative Maintenance Strategy
Merisol required preventative maintenance strategies to increase both the reliability and
availability of the critical rotating equipment. The objective was to look at a practical and
efficient solution and keeping in mind the financial implication.
Pump Inspection Permit System
To investigate changing the pump inspection philosophy and to propose an alternate
solution to increase the frequency of pumps inspections if applicable. The Sasol Group
Procedure for Work Permits (SSC-SAF-GPR-00003) outlines the necessary rules to
exempt pump inspections from the permit process.
F7101B Containment Area
An investigation into the F7101B (Value CA) tank containment area was carried out.
This was to verify that the concrete containment walls will be suitable, to contain a
leak, overfilling or rupture from F7101B. The capacity of the current concrete
containment walls was measured and compared to the maximum and operating
capacity of the tank.
FER – Analytical Report
Sasol Infrachem Merisol has an FER severity index 10 times higher than the overall Sasol
Infrachem Business Units. This is unacceptable. This report aims to decrease the severity and
frequency of FER incidents by identifying the common failure modes through FER data
From the data captured (Sasol FER Severity Calculator) thus far, we were able to identify the
following as possible high priority areas for the Merisol business to focus on:
Lines left open
Additional investigation indicated the following:
Leaving process lines open, display a steady reoccurrence in accordance to the data captured.
Lines left open is a result of valves or drains open to atmosphere, where an unintended release
takes place. There has been a steady decline in gasket related failures throughout the four
years analysed. Corrosion related failures are on the rise overall.
Figure 13 is a more detail set of data, for the current year (2013). This allows us to see what
the relevant incidents are and their impact on the overall FER severity index.
Prior to the analysis of the FER data, it was assumed that gasket failures were a major
contributor to the high FERs at Merisol. However, after analysis it was evident that gasket
failures should not given a high priority to their role in FERs as it only appears twice during
2013. Corrosion has shown a steady decline in 2013. Whereas, process lines being left open
is on a slow rise in frequency.
This gave us the data we needed to identify that Lines left open and corrosion are the main
and most relevant contributing factors to the high FER severity index and is where priority
should be given.
To solve the current and most relevant contributing factor that is lines being left open; would
be to review problematic standard operating procedures, provide appropriate training to
operators where applicable, ensure competency of the operators before being allowed to
operate the plant and review that the correct check lists are in place to ensure that no lines
have been left open unintentionally. Prioritising this as a problem correctly, could result in a
32% reduction in the FER index.
Integrity of C43164 due to crystallisation of E29 overheads
During Value CA mode the E29 Overhead steam needs to be routed to the feed tank F5113A.If
this is forgotten or overlooked the product in C43164 might crystallise on the shell side due to
the high content of phenol and ortho-cresol. The crystallization point of the mixture is < 37 °C.