Nozzle loads Economizer
Nozzle loads Economizer
(OP)
Hello piping engineers,
I need to design feedwater piping that is connected to an economizer. ( DN 250, 10";Pdes=25 Barg;Tdes = 226°C). The manufacturer of the economizer states that all nozzle loads must be avoided in Z-direction (gravity).
Can anyone tell me if the vendor is right about this, I think that he should issue some max load values to us?
How can I make this clear, is there a code for economizers like there is for rotating equipment and pressure vessels?
Kind regards,
StressedPiper
I need to design feedwater piping that is connected to an economizer. ( DN 250, 10";Pdes=25 Barg;Tdes = 226°C). The manufacturer of the economizer states that all nozzle loads must be avoided in Z-direction (gravity).
Can anyone tell me if the vendor is right about this, I think that he should issue some max load values to us?
How can I make this clear, is there a code for economizers like there is for rotating equipment and pressure vessels?
Kind regards,
StressedPiper





RE: Nozzle loads Economizer
I would not deal with a vendor who could not do so. All the ASME B31 series codes state not to violate equipment nozzle load limits. Only the vendor knows what reactions their equipment is capable of safely handling without failure, therefore they must provide me with that information.
Often times I find vendors don't like to go to their engineers to get the numbers for me. Usually takes a week or two time wise and sometimes requires few threats regarding never specifying their equipment again to get the info I need to do my job.
Just my two cents worth.
Always remember, free advice is worth exactly what you pay for it!
RE: Nozzle loads Economizer
In the meantime, locate a constant load spring can nearby and try to minimize the load there.
**********************
"Pumping accounts for 20% of the world's energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies) http://virtualpipeline.spaces.live.com/
RE: Nozzle loads Economizer
Edward L. Klein
Pipe Stress Engineer
Houston, Texas
"All the world is a Spring"
All opinions expressed here are my own and not my company's.
RE: Nozzle loads Economizer
rmw
RE: Nozzle loads Economizer
Generally speaking, I agree will all of the comments above.
I would like to add that, for many equipment vendors, allowable nozzle loads are a "game" that may enable the vendors to bill "extra charges" at the end of the contract when he reviews and approves "excessive" piping loads from the AE firm.
All loads, of course, become "excessive" when the allowable is zero....
ColonelSanders: You have said:
"All the ASME B31 series codes state not to violate equipment nozzle load limits."
Really...??? Where..???
My opinion only
-MJC
RE: Nozzle loads Economizer
ASME B31.1 "119.10.2 Reaction Limits. The reactions computed shall not exceed limits which the attached equipment can sustain. Equipment allowable reaction limits forces and moments) on piping connections are normally established by the equipment manufacturer."
ASME B31.3 "319.1.1 Basic Requirements. Piping systems shall have sufficient flexibility to prevent thermal expansion or contraction or movements of piping supports and terminals from causing: (c) detrimental stresses or distortion in piping and valves or in connected equipment pumps and turbines, for example), resulting from excessive thrusts and moments in the piping"
ASME B31.5 "519.1.1 Objectives : Piping systems shall be designed to have sufficient flexibility to prevent thermal expansion from causing: (c) detrimental distortion of connected equipment (pumps, turbines, valves) resulting from excessive thrusts and moments"
ASME B31.9 "919.7 Reactions: Terminal reactions and resulting moments shall be taken into consideration where supporting structure or connected equipment is likely to be affected by such loadings.Determination of these loads may require analysis as specified in para. 919.4.1(b)."
These force an evaluation of the reaction at conected equipment, since the equipment is normally supplied by a vendor, the vendor must provide real limits to compare to. Otherwise there is no way to judge the acceptibilty of the reactions, and it becomes nigh on impossible to meet code.
Just my two cents worth, (except the code quotes, those are fact)
Always remember, free advice is worth exactly what you pay for it!
RE: Nozzle loads Economizer
Codes only give the minimum requirements.
Just because something is not specifically stated in the code does not mean you don't have to do it.
**********************
"Pumping accounts for 20% of the world's energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies) http://virtualpipeline.spaces.live.com/