Case 32: SAE 10 Lube Oil - Laminar Flow in Valves
Reference: Flow of Fluids – Technical Paper No 410, 1988, Crane Co. Page 4-4, Example 4-7
Pipe Flow Expert File: Case_32_SAE_10_Lube_Oil_Laminar_Flow_In_Valves.pfe
Problem Description:
A 200 foot long 3” diameter steel pipe (schedule 40) carries SAE 10 Lube Oil at 60°F.
The head of fluid in the supply tank is 22 ft.
The piping includes 6 standard 90° elbows and a flanged ball valve with a conical seat.
Find the fluid velocity in the pipe and the rate of discharge.
Fluid Data: SAE 10 Lube Oil at 60°F
Result Comparison:
Data Item |
Published data |
Pipe Flow Expert |
Fluid Velocity in Pipe (ft/s) |
5.13 |
5.271 |
Rate of Discharge (gpm ) |
118 |
121.46 |
Reynolds Number |
1040 (1st Iteration) |
1096 |
Friction factor |
0.062 (1st Iteration) |
0.05840 |
Commentary:
The published data and the calculated results differ by around 3%.
The published text acknowledges that the problem has two unknowns and requires a trial and error solution.
The published data results are for the first initial assumption of velocity.
Pipe Flow Expert performs numerous iterations to find a solution which is accurate to within 0.0004 ft head
pressure loss.
A new valve fitting was created in Pipe Flow Expert to model the flanged ball valve as this item is not included in the database of standard valves and fittings.