RE: Flex analysis

From: <Steve>
Date: Fri May 13 2005 - 03:46:00 EDT

Hi Guerrat

unfortunately I cannot agree with using 70C to allow for solar effects. Some pipes can get much hotter, especially when empty, and empty pipes happen.
For long lines in sunny equatorial climates, I always do rough sums, breaking the line into the straight portions between bends and estimating the bending stresses at the major direction changes. If the roughly estimated bending stresses are below 20% of residual allowables (depending on service severity) and there are no code compliance issues, I will make due allowance for expansion and leave it at that. If not I will go the whole nine yards.
Solar gains are not that difficult to work out; its just an iterative thing once you have settled on the design radiation, surface emissivity and the sky temperature.
I should think some PEs will jump on me now, so I'll leave it at that. By the way, working it out is fun, and it gets easier each time. Plus you wind up eventually being a guru.

Cheers

Steve

-----Original Message-----
From: PipingDesign@yahoogroups.com [mailto:PipingDesign@yahoogroups.com] On Behalf Of Kuswadi@ikpt.com
Sent: Friday, May 13, 2005 1:01 PM
To: PipingDesign@yahoogroups.com
Subject: Re: [PipingDesign] Flex analysis

for very long piping line, although the fluid temperature is at ambient temperature, we shall consider the solar radiation effect, the most severe condition, which could produce long thermal movement. 1. so piping engineer shall calculate such system at Solar radiation temperature, u can input 70degree C for calculation, or 40/50 centrigrade, depend on ur calculation requirement. 2. input for nozzle thermal movement if any 3. u can consider to make piping loop to absorb thermal movement

Best Regards

Muhammad Kuswadi
Piping Mechanical Engineer
PT IKPT
Engineering Procurement and Construction Jl. MT Haryono Kav 4-5
Jakarta 12820
Indonesia
Enjoy allways ur life

                     "gguerrat"

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                     05/13/2005 05:39

                     AM

                     Please respond to

                     PipingDesign

Hi

Im related with the analysis of a carbon steel 8 in pipe for water ambient temperature instaled on exterior on suports with a lenght of 900 meters.

do any know if this type of system requieres, flexibility analysis for the lenght and for the temperature on sun conditions about 45 or 50 centigrades

Thanks

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