NAS 5 lube oil cleanliness achieved through high velocity lube oil flushing system
Place: A steel plant in Rourkela with production capacity - 4.5 MTPA
Date of Execution: 20th July 2019
Equipment Criticality: High
A Steam turbine blower was to be commissioned in a steel plant by a leading EPC company, the pipelines were erected on the site and as per the Standard Operating Procedure listed by the Steel Plant Owner Company the flushing was completed with a single auxiliary pump at 1500 LPM. However, during the trial run of the turbine, the inline lube oil filters would clog very frequently and lead to halted operations.
Frequent clogging of inline lube oil filters were hindering the operations and delaying the steam turbine commissioning project
On inspection, a root cause analysis was done and the required rate for effective flushing was calculated as 3500 LPM. The Particle contamination level was also found to be NAS 10. Hence following things were concluded:
1. The rate at which flushing was done was too low and lead to ineffective flushing, leaving a lot of debris and scale inside the pipeline.
2. Absence of a System other than the inline filters to arrest the particles which would come along with the flushing flow.
3. The maximum flow rate that could be achieved on-site was 3000 LPM.
What Minimac did:
1. The calculated effective rate for flushing was 3500 LPM, but as only 3000 LPM was achievable on-site, the temperature of the fluid was increased by regular heating arrangement to bring down the required flowrate requirement to 2500 LPM.
2. Both the auxiliary pumps were employed for flushing activity and a separate filtration skid was offered which could handle the full flow volume that was getting generated.
3. Duplex type filtration housing on the lube oil return side was also provided to arrest any future debris. Subsequently, turbine governing and Heat Exchanger were also taken online to clean the system in totality.
The Lines were successfully flushed and a NAS 5 lube oil cleanliness level was achieved.
We at Minimac Systems Pvt Ltd. provide services Oil Purification, Oil Flushing, Oil Condition Monitoring that helps you reduce downtime and increase machine reliability.