Mothballing Pumps

With slowdowns at a number of industrial facilities due to the recession, it’s a good time to discuss cutting back and saving our pumps as production slows.

By Robert L. Matthews

With slowdowns at a number of industrial facilities due to the recession, it’s a good time to discuss cutting back and saving our pumps as production slows.

Taking Them Out of Service

We must protect pumps when we shut down part of a process, which is about the same as long term storage for equipment. A few steps to remember:

  1. Protect the bearings with vapor phase (VP) oil. Fill the housings with the VP oil, then drain to 10% capacity and seal it up. This way, bearings and other carbon steel components won’t rust. Oil mist is a great way to protect stored equipment. Another option is to apply a nitrogen purge to the bearing housing, which prevents oxidation from occurring.
  2. Set up a preventative maintenance schedule to rotate the pump every six weeks or two months, this will keep the bearings moving so they don’t brinell, or cause indentions in the bearing race created by the weight and vibration of the ball load over extended time – a leading cause of failure to pump and motor bearings. This is needed for the attached motor as well.
  3. Drain and dry the volute, so liquid spoilage doesn’t damage the wet-end components. Stainless steel wet ends will be okay, but cast iron and carbon steel will need a protective coating that won’t pollute the process when start-up occurs.
  4. Coat all exposed, unpainted metal surfaces with a preservative oil.
  5. Cover the entire pump with a weather resistant covering such as a canvas or plastic tarp.

Manufacturers Instructions

Always check with the manufacturer’s specific instructions on storage. This is for storage in an outdoor environment – and, for indoor equipment, it might be a little overkill with steps 4 and 5. Length of storage time and/or demand restart can alter slightly the storage procedure. If the pump is now a back-up pump then put a vapor phase additive in the pump oil and your pump is ready to go at the push of a button.

Freezing Weather Conditions

Freezing weather can cause problems for equipment when pumping water based fluids that expand in volume when changing from a liquid to a frozen solid state. For example, when water is left in a pump fluid end and exposed to freezing temperatures, the expansion of the water as it freezes can rupture the casing of the pump and cause expensive damages.

Conclusion

These are a few ideas to make sure that as the economy does begin to rebound and you’re bringing idle production lines back up to speed, related pump equipment is ready for the job. Take precautions now, to ensure you minimize the effort later.


About the Author: Reliability manager for Houston-based Royal Purple Ltd., Bob Matthews has 35+ years of pump industry experience – from hands-on to supervision, in-plant maintenance management, consulting and training. He has taught advanced pump classes for Fortune 500 companies, universities, the Vibration Institute, ASME and FSA. Contact: www.royal-purple.net

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