Multiple Inline Restriction Let-Down Orifices
Multiple Inline Restriction Let-Down Orifices
(OP)
In a case where a restriction orifice will be used in a minimum flow line for a pump, is there a rule-of-thumb way to determine 1)if more than one orifice is needed, and 2)about how many stages are required?
For example, there is a charge pump application where the discharge side of the orifice will be at 860 psig and suction side at 35 psig. (straight run diesel at 380degF, say 0.70 SG at FTP and vapor pressure of 9.0psia)
Feels like a situation where multiple orifices may be needed, but would like to be able to confirm and estimate how many.
Thanks in advance for any help.
For example, there is a charge pump application where the discharge side of the orifice will be at 860 psig and suction side at 35 psig. (straight run diesel at 380degF, say 0.70 SG at FTP and vapor pressure of 9.0psia)
Feels like a situation where multiple orifices may be needed, but would like to be able to confirm and estimate how many.
Thanks in advance for any help.





RE: Multiple Inline Restriction Let-Down Orifices
In any event, as an alternative, this is a paper on sizing muliple orifices. Essentially, you size the last orifice first such that the pressure in the vena contra just reaches the vapor pressure of the fluid. Then the next one is sized and so on up the line so you never have cavitation. The paper also includes how far apart to space each orifice.
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RE: Multiple Inline Restriction Let-Down Orifices
Maybe I live a sheltered life but I find your link method to be as interersting as the article. By the way, the article looks like it came from Chemical Engineering magazine, can you give the details of the publication (journal, date, etc).
RE: Multiple Inline Restriction Let-Down Orifices
Let me take a look at my copy at home EGT01. It's from quite a while back, I saved it when I was working at the AGEC ethylene plants in Red Deer, AB so that's pushing 20 years ago. It was written by a couple of people working for Ontario Hydro at the time.
RE: Multiple Inline Restriction Let-Down Orifices
RE: Multiple Inline Restriction Let-Down Orifices
RE: Multiple Inline Restriction Let-Down Orifices
See also Lin S.H. Hydrocarbon Processing, July 1985, pgs 93-95
RE: Multiple Inline Restriction Let-Down Orifices
http://www.lindahall.org/