V. SUPPLY SYSTEM CONSIDERATIONS
E. Reynolds Number
The Reynolds Number (Re) is used in closed conduit/pipe flow, deals with the viscous force in a liquid, and is defined by the following equation:
Re = r1 df n1
m1
Where,
Re = Reynolds Number
r1 = liquid density at flowing temperature, lbm/ft3
df = pipe inside diameter, feet
n1 = liquid flow velocity, ft/sec
m1 = liquid viscosity
(centipoise divided by 1488 or centistokes multiplied by S.G. then divided by divided by 1488)
Customarily; turbulent flow occurs when the Re is greater than 3000, laminar flow occurs when the Re is less than 2000. The transition period is when the Re is between 2000 and 3000.
Example 11:
A 14" schedule 30 piping system is designed to deliver 18,970 BPD (553.3 GPM) of crude oil with a Kinematic viscosity of 50 centistokes and S.G. = 0.8 @ 100°F.
Find the Reynolds Number (Re).
Re = r1
df n1
= 49.92 x 1.104 x 1.28
m1 0.02688
Re = 2624.2
Where,
r1 = 62.4 x 0.8 = 49.92 lbm/ft3
df = 13.25 = 1.104 feet
12
n1 = 553.3 = 1.28 ft/sec
2.45 (13.25)2
m1 = 50 x 0.8 = 0.02688
1488
