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Fluid Velocity In Pipeline 1
- Thread starter qazx
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1
- #4
qazx
i would add that there is a criteria in API 14E mainly for hydrocarbon fluids on erosion velocity. Its
velocity= C/SqRoot(density)
density in lb/ft3 and velocity in ft/sec. C is a constant, value 100 for continous service and 120 to 150 for discontinous service
ukn
i would add that there is a criteria in API 14E mainly for hydrocarbon fluids on erosion velocity. Its
velocity= C/SqRoot(density)
density in lb/ft3 and velocity in ft/sec. C is a constant, value 100 for continous service and 120 to 150 for discontinous service
ukn
johbil
Bioengineer
- Nov 2, 2002
- 5
When you talk about erosion corrosion a lot depends on the fluid and its properties. For entrained air in water a practical limit of 5 M/S (15 ff/s) has been proposed. At that velocity you will have an appreciable pressure loss per length unit. In my opinion you want to stay away from that high a velocity. (energy and equipment concerns)
If here are however abrasive particles in the liquid, the maximum velocity drops to about 1.5 m/s or 4.5 ft/s). We have arrived at this velocity by trial and error. We have one application in which an 15% ds abbrasive in acidified water is used. The solution is pumped in stainless steel piping. By adhering to this maximum velocity we have succesfully reduced the occurence of erosion corrosion.
If here are however abrasive particles in the liquid, the maximum velocity drops to about 1.5 m/s or 4.5 ft/s). We have arrived at this velocity by trial and error. We have one application in which an 15% ds abbrasive in acidified water is used. The solution is pumped in stainless steel piping. By adhering to this maximum velocity we have succesfully reduced the occurence of erosion corrosion.
SagarSanjeev
Mechanical
It depends on the fluid you are handling if you are dealing with oil coolers than the normal fluid flow velocity through tubes (water) is 1.5 to 2 m/sec as per API recommendations.
qazx, Velocity limitation is due primarily to "water hammer" problems that occur when valves and the like are open and closed during system operation. The fundamental equation for the subsequent pressure rise that can occur is as follows:
P=M*dv/dt
where:
P=pressure rise
M=mass of fluid
v= mean velocity of pipe flow
t=time closure of valve
So what happens when the velocity is high? Pressure rise is high. Or What happens when time of closure approaches 0?
Pressure rise approaches infinity. Now what happens when the pressure rise is greater than allowable system pressure? Opps! the system just blew up! I won't mention vibration problems, cyclic pressure loads and fatigue of the piping or system components.
If the fluid stream is abrasive and or corrssive, high velocities will increase erosion/corssion rates.
Hope this this provides an insight into the rational for limiting fluid velocities.
saxon
P=M*dv/dt
where:
P=pressure rise
M=mass of fluid
v= mean velocity of pipe flow
t=time closure of valve
So what happens when the velocity is high? Pressure rise is high. Or What happens when time of closure approaches 0?
Pressure rise approaches infinity. Now what happens when the pressure rise is greater than allowable system pressure? Opps! the system just blew up! I won't mention vibration problems, cyclic pressure loads and fatigue of the piping or system components.
If the fluid stream is abrasive and or corrssive, high velocities will increase erosion/corssion rates.
Hope this this provides an insight into the rational for limiting fluid velocities.
saxon
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