AIM Manual
Motor Application » Pumptec Products (Page 8)
Hot Water Applications (Continued)
2. Determine pump horsepower required from the pump manufacturer’s curve.
Fig. 2: Manufacture's Pump Curve
3. Multiply the pump horsepower required by the heat factor multiplier from table 8.
Table 8 Heat Factor Multiplier at 3 ft/s (.91 m/sec) Flow Rate
| Maximum Water Temperature | 1/3 - 5 hp .25 - 3.7 kW | 7 1/2 - 30 hp 5.5 - 22 kW | Over 30 hp Over 22 kW |
| 140 °F (60 °C) | 1.25 | 1.62 | 2 |
| 131 °F (55 °C) | 1.11 | 1.32 | 1.62 |
| 122 °F (50 °C) | 1 | 1.14 | 1.32 |
| 113 °F (45 °C) | 1 | 1 | 1.14 |
| 104 °F (40 °C) | 1 | 1 | 1 |
4. Select a rated hp motor on table 8A whose Service Factor Horsepower is at least the value calculated in Item 3.
Table 8A Service Factor Horsepower
| hp | kW | SFhp | hp | kW | SFhp | hp | kW | SFhp | hp | kW | SFhp | |||
| 41642 | 0.25 | 0.58 | 3 | 2.2 | 3.45 | 25 | 18.5 | 28.75 | 100 | 75 | 115 | |||
| 41641 | 0.37 | 0.8 | 5 | 3.7 | 5.75 | 30 | 22 | 34.5 | 125 | 93 | 143.75 | |||
| 41702 | 0.55 | 1.12 | 7.5 | 5.5 | 8.62 | 40 | 30 | 46 | 150 | 110 | 172.5 | |||
| 1 | 0.75 | 1.4 | 10 | 7.5 | 11.5 | 50 | 37 | 57.5 | 175 | 130 | 201.25 | |||
| 1.5 | 1.1 | 1.95 | 15 | 11 | 17.25 | 60 | 45 | 69 | 200 | 150 | 230 | |||
| 2 | 1.5 | 2.5 | 20 | 15 | 23 | 75 | 55 | 86.25 |
Hot Water Applications - Example
Example: A 6" pump end requiring 39 hp input will pump 124 °F water in an 8" well at a delivery rate of 140 gpm. From Table 7A, a 6" flow sleeve will be required to increase the flow rate to at least 3 ft/s.
Using Table 8, the 1.62 heat factor multiplier is selected because the hp required is over 30 hp and water temperature is above 122 °F. Multiply 39 hp x 1.62 (multiplier), which equals 63.2 hp. This is the minimum rated service factor horsepower usable at 39 hp in 124 °F. Using Table 8A, select a motor with a rated service factor horsepower above 63.2 hp. A 60 hp motor has a service factor horsepower of 69, so a 60 hp motor may be used.