2 replies to this topic

[Gaston_Engineer]

Hi Everybody

 

I need to select a positive displacement pump for glycol,. I have checked  many suppliers' websites, but I could not find the performance curves.

I am writing to ask if someone could indicate me a link where it's available for downloading at just to have an idea. 

 

The process requires to pump the glycol miixed with water form 1.3 bar to 46 bar. The volume flowrate is 8.9 gpm.

 

Thanks in advance 

 

Gastón

[Pilesar]

For an application like this, I would fill out a pump data sheet as completely as I could, then send it to my pump vendor. The specialist there would select applicable pumps and have me review the selection. The two of us would work together to get the best pump for the service. Because the specialist is very knowledgeable and helpful, I return with more business later. It is a nice arrangement.

[Art Montemayor]

Gastón,

 

I've had a lot of experience in specifying, installing, & operating positive displacement pumps - from pumping cryogenic liquids (Liquid Oxygen, Nitrogen) to down-hole pumps handling waste fluids to oil reservoirs.  I've also applied piston positive displacement pumps to TEG (Triethylene Glycol) systems for natural gas dehydration.  Perhaps I can contribute some experience to your efforts.

 

You say you are looking for "performance curves" for glycol positive displacement pumps pumping glycol from 1.3 bar to 46 bar.

 

Unfortunately you are not specific in your specifications:

• Do you mean to pump the fluid known as pure glycol?  Or do you mean a glycol compound - like TEG?
• When you state "positive displacement" you need to fully identify WHAT TYPE of positive displacement pump you mean.  There are quite a few - from piston or plunger and diaphragm to rotary types.  Which one is of interest?  Do you really need a duplex?
• "Performance curves" for positive displacement pumps - especially the reciprocating piston and plunger type are rare to find or produce.  Basically, the inherent ability of this type of pump negates the need to have a performance curve in most cases.  However, you can probably obtain a performance curve if so desired or needed - for an extra price from the pump fabricator.  Reliable manufacturers will guarantee the performance specified.  However, you have to pay extra if you want to have a curve to see how the performance varies with respect to flow rate and developed head.

 

I have, in the past - when I was a young, curious engineer - calculated the expected capacity of these types of pumps and found that my calculated value was very close to the actual, delivered flow rate.  Consequently, I never bothered in worrying about the pulsations produced by this type of pump and applied surge flow capacity in the discharge lines.

 

Is a performance curve really necessary for your application?  You will find that conventional pumps of this type used for chemical and additive injections into processes are considered accurate enough to employ without the need any flow measurements.  An explanation of your application would be useful.