Running Lube during main pump on standby

[extremechanical]

I have been asked to examine if keeping the lube oil pump running when the main pump itself is on off condition help prevent the corrossion on bearings

Similarily, to keep seal quench running even when pump is on off condition.

Could anyone help to examine this and what are the factors I have to examine here

Thanks

 

[Artisi]

How long will the pump be "off" for bearing corrosion to be considered a problem? - seems like overkill to me.

Why keep the seal water running when the pump is off?

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[CaracasEC]

We have a lot of stand-by lube oil pump being used on our compressor systems. However, this are not normally run in addition to the main oil pump. Corrosion on bearing is not possible unless there is water contamination of the lube oil system.

 

[vpl]

The only reason I've heard of keeping lube oil running when the "pump" was off is for diesel generators at nuclear plants in cold climates. The reason isn't corrosion, but to keep the internal tempertures at a minimum level so that the diesels can start in under 10 seconds.

Not precisely clear on the term "seal quench"; however, again in the nuclear field, I know that supplementary cooling water is supplied to reactor coolant pump seals at some nuclear plants in order to keep them from overheating -- whether or not the reactor coolant pumps are running.

The applicability of the above statements to your <unknown> field is, of course, unknown.

Patricia Lougheed

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[BigInch]

We do the same in cold climate pipelining, a preheat before start up, to save total warmup time when starting up. I thought about mentioning that, but corrosion seemed to be the concern, not cold climates.

Seal quench is keeping the seals wet, so they don't dry out, lose seal and start leaking.

We are more connected to everyone in the world than we've ever been before, except to the person sitting next to us. Lisa Gansky

 

[clay87]

This "on off" terminology is confusing me.

Is the machine in a "standby" mode and required to immediately start if needed? If so then you probably want lube oil and seal quench running (vpl has alluded to this).

Regarding bearing corrosion, warm oil flowing over a bearing could help remove any moisture present in the environment and prevent condensation scenarios.

The seal question depends on application. Is the quench performing a cooling function? Is the quench acting as a barrier?

 

[BigInch]

Simple. Off = primary pump not turning; lube oil pump running.

Then again, water will sink to the sump if the lube oil pump is off.

We are more connected to everyone in the world than we've ever been before, except to the person sitting next to us. Lisa Gansky