Centrifugal Pump Nozzle Loads Verification
Centrifugal Pump Nozzle Loads Verification
(OP)
Hi,
Are centrifugal pump nozzle loads solved for the operating temperature or are they solved for the design temperature? In my piping stress model I have defined the design parameters as T1 & P1, and the operatin parameters as T2 & P2. The pump is a centrifugal In-Line Vertical pump. Any suggestions are appreciated.
Regards,
One Point
Are centrifugal pump nozzle loads solved for the operating temperature or are they solved for the design temperature? In my piping stress model I have defined the design parameters as T1 & P1, and the operatin parameters as T2 & P2. The pump is a centrifugal In-Line Vertical pump. Any suggestions are appreciated.
Regards,
One Point





RE: Centrifugal Pump Nozzle Loads Verification
So far as pump loads, or for that matter loads applied to any connected equipment is concerned, you need the realistic worst coincident temperature and pressure combination that the pump will be exposed to. The equipment manufacturer should have designed to the same loads. Remember that it is quite acceptable FOR NOZZLE LOADS (and support/restraint loads) ONLY, to use the hot Young's modulus in a pipe stress calc.
RE: Centrifugal Pump Nozzle Loads Verification
Acceptable to who and on what basis?
RE: Centrifugal Pump Nozzle Loads Verification
The use of cold modulus regardless of temperature is specifically required in the B31 and similar codes and is well documented. It relates to stresses alone. It may be convenient to use the cold modulus only to simplify a stress calc, but it may also be hugely over-conservative with regard to thermal loads.
Perhaps turn the argument on its head .... Say you are designing a turbo-expander for an FCC plant, operating at 750 deg C. When considering casing stiffness, blade clearance and shaft alignment, would you use the hot or cold modulus ? Q.E.D.
For good form I always include a statement clarifying use of the hot modulus in any project stress analysis procedure, which will of course be Client approved.
RE: Centrifugal Pump Nozzle Loads Verification
B31.1 explicitly shows that E_h should be applied for reaction load calculations. Should have looked before I lept.