pressure drop through a reducer 1

[myango]

would like to know how to compute the pressure drop through a reducer from 20 inches to 12 inches if the inlet of the reducer has 195 centrigrade 77t/hr of crude oil column overhead vapour

 

[katmar]

There is very little published data for standard pipe reducers. Hooper (Chem Eng, Nov 7, 1988, pg 89-92) says reducers give very little resistance when flowing from large to small, but are effectively sudden expansions when flowing from small to large.

In the reduction mode Hooper's equation is
K = (0.1 + 50/Re)( (D/d)^4 - 1 )

where
Re is based on inlet (large) diameter
D is inlet (large) diameter
d is small (outlet) diameter

A conical tapered reducer would give a higher K value than this.

Katmar Software
Engineering & Risk Analysis Software

http://katmarsoftware.com

 

[tickle]

Crane has a method. I cannot comment on its accuracy.

 

[myango]

thanks guys,
for now let me use Katmars formula but generally speeking it seems its its difficult to calculate