| Term: |
|
| Duty point: |
Customer requirement that plots flow (GPM) and head (feet) on the pump curve |
| Critical lifts: |
Suction lifts greater than 25 feet are considered critical lifts. The appropriate curve should be read when plotting duty points |
| Flooded suction: |
Any time a positive pressure exists on the suction side of the pump |
| Static Suction Lift: |
The vertical distance from the lowest suction point to the eye of the impeller |
| Suction Friction Loss: |
The resistance encountered in the suction piping |
| Total Dynamic Suction Head: |
The sum of the suction lift and the suction friction loss |
| Static Discharge Lift: |
The vertical distance from the eye of the impeller to the discharge point |
| Discharge Friction Loss: |
The resistance encountered in the discharge piping |
| Total Dynamic Discharge Loss: |
The sum of the discharge lift and the discharge friction loss |
| Total Dynamic Head: |
The sum total of resistance, DSH + DDL in a pumping application expressed in feet |
| Velocity, Feet Per Second: |
The maximum recommended velocity of liquid through pipe or smooth bore hose is 12-14 feet per second. Velocities greater than 14 feet per second require excessive amounts of energy and result in turbulent flow. |
| Laminar Flow |
Sometimes called Stramline Flow & the opposite of turbulent flow; a flow regime characterized by high momentum diffusion and low momentum convection. |
| Cavitation |
Exist when pressure in suction or discharge line falls below vapure pressure, vapor is formed and moves along with the stream. These vapor bubble or "cavities" collapse when they reach regions of high pressure on the way through the pump |
| Viscosity |
The internal friction of a liquid or that property which resists any force tending to produce flow |
| Net Positive Suction Head Required |
NPSHr required by the pump in order to prevent cavitations for safe and reliable operation of the pump. The required NPSHr for a particular pump is in general determined experimentally by the pump manufacturer and a part of the documentation of the pump. |
| Net Positive Suction Head Available |
NPSHa can be determined during design and construction, or determined experimentally from the actual physical system. NPSHA is the amount the pump intake after pipe friction losses and head pressures have been taken into account |
| Prime 3 PT A series |
Primarily horizontal, low head pumping. Are capable of handling large quantities of water at lower total dynamic head ratings of 60-130 TDH |
| Prime 3 PT B series |
Primarily vertical discharge or pumping into pressure. Are capable of handling quantities of water at significantly higher total dynamic head ratings of 140 TDH and up |
| Prime 3 PT C series |
Primarily vertical discharge or pumping into pressure. Are capable of handling quantities of water at significantly higher total dynamic head ratings of 200 TDH and up |
