Re.engineerOPTIMIZING CONDENSATE PUMPS
CONTRIBUTING RE.ENGINEER
Keith Lapeyrouse
Process Reliability Solutions, www.prs-llc.com
CHALLENGE
It’s amazing how pesky condensate pumps can be. But think about it. They are the least important part of a project typically bought at the lowest cost by the least experienced member of the team. Forty years ago, I was working at a chemical plant and it had 3 low pressure (L.P.) condensate return systems that was costing the plant $22K per year in maintenance.
SOLUTION
Let me describe the three different systems:
The 1st L.P. Condensate Return System was 20 years old. It had a ground mounted supply tank with dual condensate pumps (perhaps they expected unreliability). Each of the condensate pumps were center mounted (meaning two seals per pump). It failed often and cost $22K per year in Maintenance.
The second was 10 years old. The reservoir was about 4' above the tank. It had a single condensate pump center mounted (meaning two seals). The extra NPSHa from the elevated reservoir really helped. It only failed twice per year and cost 7K per year in Maintenance.
The last (3rd System) L.P Condensate Return System was 3 years old. It was by the same manufacturer as the second, so the reservoir was about 4' above the tank. It had a single condensate pump which was overhung (one seal). It had a spare pump in the warehouse. It had good performance!
RESULT
One day, when the 2nd system pump failed, I used the spare from the 3rd system and it became my second system. It ran great! I started staving the $7k/yr. After it ran well for a while, I convinced the plant to upgrade the 1st system. The new system installed was the cost of maintenance for a year. So what's the point of the story? The cash was my salary at the time. The NPV is about $250K at this point. Fixing the small things pays big dividends!
IMPACT
$250K