pipeline allowed deflection
pipeline allowed deflection
(OP)
Hi everyone,
A buried cased transmittion steel pipeline with dimater of around 1 ft and internatl pressure of around 2100 Kpa experience maximum deflection of 1 in along a 25 m length due to surface loading. How can one know that this deflection is acceptable in terms of servicability/integrity and strength. Is there a way to calcualte strees induced in this pipelies from the imposed deflection. Thanks
A buried cased transmittion steel pipeline with dimater of around 1 ft and internatl pressure of around 2100 Kpa experience maximum deflection of 1 in along a 25 m length due to surface loading. How can one know that this deflection is acceptable in terms of servicability/integrity and strength. Is there a way to calcualte strees induced in this pipelies from the imposed deflection. Thanks





RE: pipeline allowed deflection
Δ = wL^4/384/E/I
could be solved for w and the maximum moment would have been = wL^2/8 and bending stress σ= Mc/I
RE: pipeline allowed deflection
Your best bet would be to apply an external load inside of Ceasar and have ceasar calculate the total stress on the line, if your above allowable stress of the line then you need to do something (remove the load or support the pipe)
RE: pipeline allowed deflection
HydroVAC down to the pipe at the largest deflection and place a strain gauge?
RE: pipeline allowed deflection
Soil1999, There are probably some spacers somewhere inside that casing, as 25 meters is quite a long span to go without using them. Without spacers the deflection is likely to be enough to contact and possibly short out the pipe to the casing and lose your CP.
RE: pipeline allowed deflection
RE: pipeline allowed deflection
RE: pipeline allowed deflection
Soil1999, do you mean the ring deflection (pipe ovality) or longitudinal stress (deflection). BigInnch has taken it as the second one.
RE: pipeline allowed deflection
Notably this standard is conservative and was developed for the water transmission industry.
Are there not maximum deflection criteria is other pipeline standards?
RE: pipeline allowed deflection
RE: pipeline allowed deflection
RE: pipeline allowed deflection