Dry running protection for pump in hazardous area

[123MB]

Hi All,

I have researched our local (australian) standards with no luck, looking for some requirement for dry running protection for pumps installed in hazardous areas.

I am hoping to find a clause which specifically states you must prevent dry running a (centrifugal) pump to prevent exceeding the T-rating (wrt the hazardous area classification)

Does anyone know of any such clause in the standards? or is it left to the specific requirements of the hazardous area classification of the pump itself?

There's a similar electrical requirement which states you need to prevent running when a phase is lost (to prevent overheating)

Cheers

Michael

 

[Artisi]

I would think there is a big difference between a unit running with 1 phase out which could / would lead to an over heated motor than a unit running dry which, depending on the shaft sealing configuration, may be able to run continuosly without any problem - or am I missing something with your question?

 

[123MB]

Fair enough mate, what I'm saying is that, I wouldn't be surprised if there was a one liner requirement for dry running protection on pumps, just as there is a one liner in the standards for electric motors and phase failure protection.

I'm no expert but I was under the impression most centrifugal pumps should not run dry, and under these conditions would likely damage seals and overheat in an uncontrolled manner that may not be in the context of the kind of type testing that is done on hazardous area equipment.

Hence I would expect there is a line in a standard protection somewhere to mandate the installation of dry run protection for pump control systems to reduce the likelihood...

 

[micalbrch]

I'm not familiar with the Australian standards but acc. to the European (ATEX) standard for equipment in explosion proof areas it's rather clear: If an ignition source can occur by dry running (for example shaft seals become hot), one must prevent the pump from dry running even if this requirement is not specifically listed.

 

[Artisi]

It comes down to an engineering decision as pointed out by micalbrch, if a dry running pump can be a source of ignition then it must be shutdown if it is not a source of ignition then it is ok to run. The real question is why would you want a dry-running pump running anyway?

 

[BigInch]

Heat your lunchbox?

I'd like to know why you have to have a code to prove you shouldn't be doing it? Provision of a low suction pressure shutdown would be very commonly included in that scenario to protect your pump, with or without a resulting fire. The only time I wouldn't do it is if the pump cost less than the pressure/shutdown switch.

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"Being GREEN isn't easy." Kermit

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[JLSeagull]

Does API RP 14C (offshore) apply to your project?