suction nozzle bigger than available nozzle of the tank.
suction nozzle bigger than available nozzle of the tank.
(OP)
Hello
I have to do the connection arrangement of a centrifugal pump for cryogenic service with a cryogenic tank (source), the fluid is liquid oxygen and I have this case , the nozzle of my tank is 1" and the suction nozzle of my pump is 2 1/2". Is there problem in the performance of the pump if I just put a 1 x 2 1/2" coupling to do the connection of these equipment?
thanks in advance.
I have to do the connection arrangement of a centrifugal pump for cryogenic service with a cryogenic tank (source), the fluid is liquid oxygen and I have this case , the nozzle of my tank is 1" and the suction nozzle of my pump is 2 1/2". Is there problem in the performance of the pump if I just put a 1 x 2 1/2" coupling to do the connection of these equipment?
thanks in advance.





RE: suction nozzle bigger than available nozzle of the tank.
RE: suction nozzle bigger than available nozzle of the tank.
RE: suction nozzle bigger than available nozzle of the tank.
Maybe the pump you are using is too big and its speed could be reduced to harmonize with the 1" outlet and pipe?
I would consult the manufacturer of the pump for that specific application.
If the response is positive, I would ask about the recommended type of reducer and its location respect to the suction of the pump.
"Engineering is achieving function while avoiding failure." - Henry Petroski
RE: suction nozzle bigger than available nozzle of the tank.
The pump doesn't care what the size of the tank outlet is, what is important is flow behaviour at its inlet and into the eye of the impeller.
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.)
RE: suction nozzle bigger than available nozzle of the tank.
Is there a problem doing what you're doing?
Maybe, maybe not. The missing data you need to know or advise includes:
Flow rate
Pump NPSHR
other frictional losses from tank to pump
temperature of the liquid
Height of the liquid above the pump centre line
Pressure above the liquid in the tank
Vapour pressure of the liquid at that pressure and temperature
density of the liquid (to convert pressure to head)
Then calculate the NPSHA for your system. Note nozzle exit losses need to be calculated.
If it's greater than min required, normally by more than 1m, then you should be ok.
Gut feel is that it doesn't sound good, but there is much we don't know so can't say one way or another.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: suction nozzle bigger than available nozzle of the tank.
below the process information.
I did the math and by the operation pressure of the tank the NPSHA is bigger than NPSHR.
Flow rate =120 GPM
Pump NPSHR = 4.9 ft
Line from nozzle tank to pump= 8.2 ft
temperature of the liquid=-361.4 °F
Height of the liquid above the pump centre line= 3.9 ft
Pressure above the liquid in the tank=50 psig
Vapour pressure of the liquid at that pressure and temperature=1.12 mm Hg
density of the liquid=71.17 lbs/ft3
RE: suction nozzle bigger than available nozzle of the tank.
It is very easy to cavitate in liquid gases, I would suggest a pressure sensor in the inlet line linked to a shut off.
Cavatating LOX can lead to very serious results (like fires).
= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube
RE: suction nozzle bigger than available nozzle of the tank.
RE: suction nozzle bigger than available nozzle of the tank.
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.)
RE: suction nozzle bigger than available nozzle of the tank.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: suction nozzle bigger than available nozzle of the tank.