Flange for nozzle of pump
Flange for nozzle of pump
(OP)
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Does thrust force appear at the flange of a pump?
thread378-106868
In the existing plant, I found the use of flange Class 600 at suction and discharge nozzle of pump. The shut off pressure of pump is less than the pressure rating of flange Class 300.
? Is this general practice to specify the higher rating of flange for pump nozzle?
? What is the factor to increase the flange Class? If Class 150 can withstand the internal design pressure, should we use Class 300 for margin?
Please comment.
Does thrust force appear at the flange of a pump?
thread378-106868
In the existing plant, I found the use of flange Class 600 at suction and discharge nozzle of pump. The shut off pressure of pump is less than the pressure rating of flange Class 300.
? Is this general practice to specify the higher rating of flange for pump nozzle?
? What is the factor to increase the flange Class? If Class 150 can withstand the internal design pressure, should we use Class 300 for margin?
Please comment.





RE: Flange for nozzle of pump
RE: Flange for nozzle of pump
For some applications, pumps may be mounted in series in which case each pump in the train will see an increased pressure, both at the suction flange, and at the discharge flange. It could be that, for your application, only one pump is required, with a substantially lower pressure than the pump is capable of handling.
As BRIS indicated, determine the pipe and flange class required for your system.
Cheers,
CanuckMiner
RE: Flange for nozzle of pump
RE: Flange for nozzle of pump
You dont mention if the pump is an API 610 or other standard that would help understand the question.
RE: Flange for nozzle of pump
The pump is conformed to API 610.
-Suction pressure of pump is 4 barg. The carbon steel piping upstream of pump is flange class 150.
-Discharge pressure of pump is 30 barg. The carbon steel piping downstream of pump is flange class 300.
-The hydrocarbon fluid has temperature 100 C.
-Both suction and discharge nozzles of pump are flange class 600.
I do not want to derate the existing flange...just curious about the design.
RE: Flange for nozzle of pump
flange material (i.e. allowable stress)
pressure
temperature
all three combined.
the use of a 600 flange by the manufacturer may be due to an economic factor and not a technical one...
usually the casings are cast. having different models for the same size pump just because of the flange rating may not make economic sense...
it will affect the customer at the 1st connecting flange, only.
on the other hand the manufacturer can lower the price of their units because they do not have to develop a model for each flange rating... i.e. the "one-size-fits-all" approach.
using 600# will cover most of the industrial uses except the very high pressure/high temp designs (e.g p > 1440 psi for CS or low alloy steel between -20 and 100 F or p > 70 psig for AISI 316 for t > 1500F).
the NEMA and API standars limit the forces and moments imposed on nozzles.
saludos.
a.
RE: Flange for nozzle of pump
RE: Flange for nozzle of pump
This is usually done based on experience showing that in this particular service frequenct service or maybe people stepping up on the pipes etc. requires selection to be conservative.
Best regards
Morten
RE: Flange for nozzle of pump