Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations KootK on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Centrifugal Pump Suction vs discharge nozzle 1

Status
Not open for further replies.

NewFish

Petroleum
Mar 3, 2017
9
Hello,

I came across a centrifugal pump with suction nozzle and discharge nozzle having the same size (12 in each), I know that for centrifugal pumps, suction nozzle is usually smaller the discharge one.

For what purpose does pump constructor go to such design ?

Thank you in advance
 
Replies continue below

Recommended for you

This was done on some older vertical in-line pumps. These pumps were literally designed to be dropped into an existing line to boost pressure. You could cut out a section of a line and weld flanges on the ends. The pump could be bolted to those flanges and did not require any foundation. It would hang off the pipes. In order for this to work, the suction and discharge flanges were the same size and directly in line with one another. Is this the configuration of your pump? 12 inch flanges seem large for a pump of this type.

Johnny Pellin
 
Thank you for youe quick reply,

Actually, this pump will be installed on an existing pipes, would it be safe to say that supplying a pump with such design is not unconventional ?

This pump will be discharging water from a water pit into a sand filter in a water treatment plant (Head = 9 m)

 
In general, the suction nozzle is typically larger than the discharge nozzle for NPSH and velocity issues.

In some applications, the suction nozzle and the discharge nozzle may be the same size. There are a number of pump manufacturers that offer horizontal spilt case pumps with the same size on both discharge and suction. Vertical turbine pumps may have the same size suction as the discharge.

 
I don't see any problem with this arrangement. It is not unconventional. For a simple, relatively low head water application, I would not be concerned.

Johnny Pellin
 
It is not uncommon to see pumps with the same size suction and discharge nozzle. A pump manufacturer can tell you why they do it. I am not sure why you care? As long as your suction and discharge velocity in the piping is within the recommended limits you are okay.
 
It's OK if you install it backwards, simply run it in the opposite direction 😁

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.)
 
Thanks everyone for your feedback

I am new to the world of pumps and it was an odd thing to me, so I wanted to share with you.
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor