Case 34: SAE 70 Lube Oil - Laminar Flow in Valves
Reference: Flow of Fluids – Technical Paper No 410, 1988, Crane Co. Page 4-5, Example 4-9.
Pipe Flow Expert File: Case_34_SAE_70_Lube_Oil_Laminar_Flow_In_Valves.pfe
Problem Description:
A piping system consisting of 5” diameter steel pipe (schedule 40) carries SAE 70 Lube Oil at 100°F.
The flow rate is 600 gpm (US).
The piping includes a 5” gate valve and a 5” angle valve.
Find the fluid velocity and the pressure loss across the system.
Fluid Data: SAE 70 Lube Oil at 100°F
Result Comparison:
Data Item |
Published data |
Pipe Flow Expert |
Pressure Loss (psi) |
56.6 |
56.6014 (100.000 - 43.3986) |
Fluid velocity in pipe (ft/s) |
9.60 |
9.622 |
Reynolds Number |
718 |
719 |
Friction factor |
0.089 |
0.08903 |
Commentary:
The published data and the calculated results compare well.
The system was modeled in Pipe Flow Expert with a fluid surface pressure of 100.00 psi g at the inlet to the system.
The outlet node had a resulting pressure of 43.3986 psi g.
The pressure difference is obtained by subtracting the outlet pressure from the inlet pressure.