- Power (Hits: 5920)
- Power System (Hits: 218)
- Pressure (Hits: 21166)
- Pressure Loss (Hits: 724)
- Pressure Vessel (Hits: 4439)
- Project Management (Hits: 2013)
- Projectile (Hits: 1601)
- Pulsation and Vibration (Hits: 399)
- Pump (Hits: 6985)
- Quadrilateral (Hits: 870)
- Quantum Mechanics (Hits: 397)
- Radiation (Hits: 613)
- Rectangle (Hits: 438)
- Refinery (Hits: 692)
- Relativity (Hits: 416)
- Reservoir (Hits: 655)
- Resistance (Hits: 589)
- Rotating Equipment (Hits: 408)
- Rotational (Hits: 607)
- Roughness (Hits: 1068)