RhoV2 criteria for Flare system
RhoV2 criteria for Flare system
(OP)
Rhov2 is a design limit for offshore flare systems in NORSOK P-001
But why is Rhov2 used?
NORSOK P-001 has the limit Rhov2 < 200000 kg/m/s2
What will physically happen if the limit is exceeded?
My knowledge far:
the momentum G =rho*v2
the dynamic pressure Pdynamic = rho*v2/2 by Bernoulli's eq
the axial force in a 90 deg bend F = massflow * velocity (SI units)
F may be written F=G*FlowCrossectionalArea
this gives that the bend forces(flow induced) are directly proportinal to rhov2.
(i'm not talking about pipe support forces, just internal flow induced bend forces)
Are there other resasons for limiting rhov2 ?
-vibrations?
-noise?
-acoustic fatigue?
-oscillations?
-erosion?
-pipe stress?
-slug forces?
But why is Rhov2 used?
NORSOK P-001 has the limit Rhov2 < 200000 kg/m/s2
What will physically happen if the limit is exceeded?
My knowledge far:
the momentum G =rho*v2
the dynamic pressure Pdynamic = rho*v2/2 by Bernoulli's eq
the axial force in a 90 deg bend F = massflow * velocity (SI units)
F may be written F=G*FlowCrossectionalArea
this gives that the bend forces(flow induced) are directly proportinal to rhov2.
(i'm not talking about pipe support forces, just internal flow induced bend forces)
Are there other resasons for limiting rhov2 ?
-vibrations?
-noise?
-acoustic fatigue?
-oscillations?
-erosion?
-pipe stress?
-slug forces?





RE: RhoV2 criteria for Flare system
Take a look also to this (there are interesting figures for limiting velocity):
www.standard.no/PageFiles/1134/P-001e5.pdf
RE: RhoV2 criteria for Flare system
Reference Review:
FREDERICK J. MOODY
ASME PD382 Hydraulic Loads on PVP
HOW TO PREDICT THERMAL-HYDRAULIC LOADS ON PRESSURE VESSELS AND PIPING
Introduction to Unsteady Thermofluid Mechanics, Frederick J. Moody
RECOMMENDED PRACTICE DET NORSKE VERITAS
DNV-RP-D101
STRUCTURAL ANALYSIS OF PIPING SYSTEMS OCTOBER 2008
Been their did that
L S THILL
RE: RhoV2 criteria for Flare system
Best regards
Morten
RE: RhoV2 criteria for Flare system
My main issue is to get the physical understanding of why Rhov2 is used as design criteria in flare systems.
I have worked with flare systems for 6 years (simulations, design, Norsok P-001, P-100, API 520, API521, Flarenet, Acoustic Fatigue, etc)
But still, I don't have the physically understanding of why Rhov2 is important.
RE: RhoV2 criteria for Flare system