Pumps replacement study 3

[Monagas]

Hello my friends, I need some guidance of how I should start an evaluation for a pumps replacemnt and installation of an used one.

The two pumps( 5 hp, 5 gpm @ 172 rpm electric motors) are for E.Glycol injection service in order to avoid hydrates formation at a gas processing facilities( 900 psi @ -10ºF).
The main reason of this replacemnt is the old condition. They are been operating since 1984, and has many overhauls. Now both of they, are experiencing a bad performance, and the recommendations are the replacemnt of the pumps.

We have two pumps at the warehouse that had been used for the same service in another plant. The electric motors are of the same power (5 HP @ 350 rpm)

I would like to know if a I can install this pumps at the plant, and what points do I have to consider for start the evaluation.

I will appreciate your comments

Regards

 

[Artisi]

Firstly, you need to establish what the design duty / requirements of the existing pump / system is and secondly, what is the rated output of the warehoused pump -if the performance is the same then it is likely you might be able to use it.
You also need to establish what the mechanical condition of this pump is, is it in any better shape than the one already installed.


Naresuan University
Phitsanulok
Thailand

 

[dcasto]

your conditions of 5 gpm at 900 psig call for a 3HP motor, that checks. Now the new pumps must first be able to withstand the presure and that they pump 5 gpm at the speed they are rated at. Typically on these small PD pumps, you can get higher discharge pressures by putting in smaller plungers (there is a rodload issue normally) sometimes the fluid end with the valves can be chaned out for higher pressures if required.

For flowrate, either slow the units down by resheaving (I assume that they are)or somethimes there is a gearbox that has to be changed.

Overall most pumps have a table showing all the variations of plunger size versus flow rate with maximum allowable pressures for each plunger/head.

The last thing to check is NPSH, most PD pumps require very little, but given the choice of multiple diameters and speed, I'd chose the lower speed to get the lowest NPSH and best chance of longivity.

Have an expert give it a once over too.

 

[Monagas]

Thanks to all !!, we will keep in touch

 

[powerjunx]

Monagas, try this software for free.



"ProMot, a decision support tool, is being developed within the framework of a project cofinanced by SAVE, aiming to aid end-users to explore the possibility of energy savings, in motor systems of an industrial or tertiary installation: electric motors, pumps, compressed air system and chillers. The tool helps in auditing an installation and performing simple meaningful calculations of purchasing, replacing existing or retrofitting electric motor systems. These technical and economic calculations are based on equipment data retrieved from widely accepted and regularly updated European databases and methodologies."



Download at this link,

http://promot.cres.gr/promot_plone/downloads/tools

regards,

bil

 

[Monagas]

Thank You Mr. Bill