Process Control Pump Alarms

[Jieve]

Question for the guys who deal with pumps regularly:


if the pump motor is line powered (no VFD), you have a suction pressure sensor, discharge pressure sensor, and flow transmitter measuring flow through the pump, what alarms would you typically program into a function for that pump?



Any input is appreciated. Thanks!

 

[parky]

I suppose it depends on what is important, obviously a trip situation i.e. monitor the overload, if flow is important then flow alarm based on pump running, limits on pressure (and suction if required). then I would prioritise the alarms for example, a trip would disable flow & pressure possibly so that you only get the one alarm, however, perhaps a first up alarm but enable all alarms with time stamps, that way you will know what possibly caused the error.
The flow & pressure would probably have slug delays so if the motor tripped on a short winding for example would be a first up alarm.
It will depend on the response times of the alarms for example, a motor tripped because there was little flow but high pressure, assuming the trip would take some time compared to the pressure delay allowed before alarm.
My usual stance if you can generate an alarm then do so, it can help maintenance in fault finding (you may have to teach them to look at the alarm screen before ripping the plant apart lol).

 

[cardosocea]

Instrument failure alarms in addition to the ones parky mentioned.

 

[Tom Jenkins]

I would definitely alarm low suction pressure (excess suction losses) because that is an indication of potential cavitation.

High discharge pressure or low flow will indicate line blockage or closed valve.

Low discharge pressure or high flow indicates broken line or pump failure.

Monitor the starter for motor overload.

 

[Jieve]

Very helpful answers, thanks everyone for this.