33 replies to this topic

[breizh]

Julien 

 

Other great resource about pump : http://www.pumped101...cs_displacement

 

more:

 

http://www.slideshar...-into-a-process

 

 

 

Breizh

Edited by breizh, 06 April 2016 - 04:12 AM.

[Julien123456789]

Thank you so much Breizh,

This is a great resource.

I will profit it.

 

Julien

[Julien123456789]

I have also a typical question.

Why NHSP criteria is not important for a displacement pump ?

Edited by Julien123456789, 06 April 2016 - 10:03 AM.

[fallah]

I have also a typical question.

Why NHSP criteria is not important for a displacement pump ?

 

Julien,

 

NPSH (not NHSP!) is important for PD pumps same as centrifugal ones...
 

[Julien123456789]

Fallah,

Thank you for your quick reply and sorry for my mis-typing.

In a lot of literature, they say that NPSH is not a criteria for a PD pumps.

 

In the following process, after calculating, I dont want to use a centrifugal pump because of the very low value of NPSH available.

 

Therefore, I consider using a PD pump to do this servce. That why I posted question concerning the importance of NPSH for a DP pump.

 

According to you, can I resolve the problem of NPSH when using a PD pump in this case.

 

Julien

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[fallah]

 

In a lot of literature, they say that NPSH is not a criteria for a PD pumps.

 

In the following process, after calculating, I dont want to use a centrifugal pump because of the very low value of NPSH available.

 

Therefore, I consider using a PD pump to do this servce. That why I posted question concerning the importance of NPSH for a DP pump.

 

According to you, can I resolve the problem of NPSH when using a PD pump in this case.

 

 

Julien,

 

NPSH isn't the main parameter for pump type selection; then in most cases you cannot resolve the shortage of NPSHA by pump's type change...

 

If you have already selected centrifugal pump and faced to NPSHA shortage you can use canned type pump or inducer in pump suction...

 

The PD pumps need their own NPSHA criteria per the value reported by the relevant manufacturer...
 

[Julien123456789]

Dear Mr. Fallah,

I knew a canned motor pump may be use for a leak-proof. I can not imagine how it can contribute to solve NPSHA shortage requirement.

For an inducer pump, it is not easy for using/ installing and maintenance service.

 

Facing to these challenges, which type of pump that may be the best choice ? (HCl acid transfer service).

 

 

Julien.

[fallah]

 

I knew a canned motor pump may be use for a leak-proof. I can not imagine how it can contribute to solve NPSHA shortage requirement.

For an inducer pump, it is not easy for using/ installing and maintenance service.

 

Facing to these challenges, which type of pump that may be the best choice ? (HCl acid transfer service).

 

Julien,

 

I suggested canned type pump just as a sample solution for low NPSHA applications...the exact case of low NPSHA should be investigated to find the proper solution...

 

Nowadays many types of centrifugal pumps are to be applied in HCL services; but the main point regarding such pumps is their materials of construction which should have adequate resistance to acid corrosion within the pumps life time... 

 

It's obvious that some type of PD pumps such as diaphragm pumps are more proper in low flow injection of HCL than centrifugal ones...

[Julien123456789]

Dear Mr. Fallah,

Thank you so much for your explanation.

I will post a new proper thread about acid transfer service to clarify something.

I hope always receive your comments for better understanding the suject.

 

Have a nice day,

 

Julien.