change a pump

[civil gr]

Hi everybody.
Someone could support that pumps have a lifetime about 20-25 years.
But actually when is the right moment to change a pump?
The easy answer is when of course the wire to water efficiency gets too low.
But what if you do not use so much your pump. Are there any other theoretical or empirical formulas leading you towards this direction?

 

[Artisi]

depends on usage, maintenance, product being handled, environment.
When do you change it: when its buggered, when there no spare parts available, or when the newly appointed MBA maintenance chief says to change it.

Many pumps operating in industry are a bit like King Arthur axe, its had 6 new handles but the it's still the original axe.

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.)

 

[JJPellin]

A pump should be replaced when it is damaged beyond repair. Our oldest pump was made in 1945. We bought it used in 1955 and it has been in continuous operation ever since. Based on condition at the last overhaul, it should last another 50 years, easily.

Johnny Pellin

 

[itsmoked]

That water Johnny?

Keith Cress
kcress -

http://www.flaminsystems.com

 

[bimr]

In addition to the previous comments, it also depends on somewhat on if the pump is correctly specified and installed.

 

[JJPellin]

Yes, It is in water service. Specifically, cooling tower circulation. 800 HP. 1200 rpm. Single stage, double suction, between bearings. Sleeve radial, ball thrust.

Johnny Pellin

 

[Artisi]

Johnny P. manufacturer?

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.)

 

[JJPellin]

Byron Jackson Type S, 20" L

Johnny Pellin

 

[civil gr]

I realise that your oldest pump was made in 1945 and it still works but the question remains
Shouldn't somebody try to figure out what this pump consumes and if it is worth to replace it and what benefits would arise then?

 

[Artisi]

Johnny, the reason it's still running.

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.)

 

[Artisi]

civil gr. I would suspect that a plant running something like 2000 pump units would have the expertise and know how to have analysed that this unit is paying its way.
For 800 hp cooling water duty, they would be chasing every excess cent spent in running costs.

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.)

 

[MohdYaseen2010]

I think you need to monitor the system the pump is working on first, cause your pump operating curve will not alter or change, the system curve might be changed due to different factors (production depletion, modification on the suction , fluid properties changed, etc), & so the BEP & NPSHA might changes & this will affect your pump performance & its life cycle.
If your pump is designed for certain system curve (BEP identified accordingly), & this system doesn't change then the pump should normally work for its designed life.
Of Course routinely maintenance & monitoring to its reading sensors (temperature, vibration, etc) will give proactive indication to what your pump is suffering from & what the mitigation you need to do.

Mohd Yaseen

 

[bimr]

civil gr,

It is generally hard to justify the change out of a working pump just on profitably because of the tax laws. That is why you see so many old facilities with older equipment.