Make Models Match  Readers explain how differences in pressure
can arise.  Share Print Related RSS  As part of our refinery
expansion, we must confirm the capacity of a schedule-80 crude-
oil-desalter wastewater line. It's a 2,500-ft pipeline
consisting of two heat exchangers and a mix of 3-in. and 4-in.
pipe emptying into a slop-oil decanter operating at 5 psig.
We're hoping that capacity can be increased by 25%. We collected
some data using existing pressure gauges. An initial hydraulic
study with software using equations from Crane Technical Paper
No. 410 indicated there is an "extra" 65 psi when 125 gal/min of
brine flows at 160 psig. However, another study done using
different Crane-based software gave about-50-psig extra
pressure. How could two programs produce such different results?
"Why is there a difference between two programs that both use
the Darcy method?" This should be expanded to a more general
question: "Why isn't my system working the way I think it
should?" It doesn't matter whether you ar