Exercising Redundant/Emergency Pumps

[77JQX]

I work for a water utility that has many redundant/emergency pumps installed. Most of these are split case pumps in the 100 to 200 HP range, although we also have several idle lineshaft deep well pumps. Is there literature that addresses how often these pumps should be operated to ensure they remain in working condition?

 

[JJPellin]

We have approximately 2000 pumps in our oil refinery. Of those, about 1500 are centrifugal pumps with an average size of about 100 HP. For many years, we did not have any requirement for running the spares. However, back when I started, the average pump in service was failing once every 12 months, so they got run at least that much. We found, that as our reliability improved, the spare pumps were getting run less and less. Eventually, we had severe problems when spare pumps would not run because they had been sitting idle for too long. Our current policy for all centrifugal pumps is that we switch pumps and run them once per month for at least four hours. For pumps in services where it is risky to switch pumps, we have an absolute requirement that they must be run at least once every three months. While they are running, we take vibration data to assess the health of the bearings, couplings, etc. I have not seen any literature with standards stating a maximum interval between running spare pumps.

Johnny Pellin

 

[eyec]

what does the pump mfgr have to say/recommend?

 

[BigInch]

Don't have designated spares. Rotate equipment equally through normal service hours.

Let your acquaintances be many, but your advisors one in a thousand’ ... Book of Ecclesiasticus

 

[Clvet]

For the bearings, the number I always hear floated is to rotate the shafts every three months but I don't know how much of a safety factor is built into that number. . For convenience, I would have it coincide with checking lubrication in bearing frames.

 

[GaTechTheron]

If by "emergency" you mean firepumps, there are NFPA20 guidelines for how often equipment should be run. Off the top of my head, I believe pumps need to be operated through a flow loop 30 minutes at a time, every 2 weeks. Annually, the firepump performance needs to be verified against pump OEM test curves. Finally, every three years the entire system needs to be tested for proper operation.

 

[Spud6414]

Good day all, I work in a Coal fired power facility. Here is been my experience with redundant system pumps of which we have 386 or so. For the longest time they were not getting used and a run till failure mentality was the norm. The discovery was with some units that could be a very long time and when the redundant system was started it would lose a seal or a bearing shortly after start up. We have since implemented a three month cycle of operation. This has done two things, it has allowed us a set down time for a system to perform preventative maintenance and trouble shoot suspected bearing failures due to vibration and oil analysis.

Spud