The SubDrive/MonoDrive needs only a small pressure tank to maintain constant pressure. (See Table X for recommended tank size.) For pumps rated 12 gpm (45.4 lpm) or more, a slightly larger tank is recommended for optimum pressure regulation. The SubDrive/MonoDrive can also use an existing tank with a much larger capacity.
Pump Flow Rating | Controller Model | Minimum Tank Size |
Less than 12 gpm (45.4 lpm) | SubDrive15, SubDrive 75 or MonoDrive | 2 gallons (7.6 liters) |
SubDrive20 or SubDrive100 | 4 gallons (15.1 liters) | |
SubDrive30, SubDrive150 or MonoDriveXT | 4 gallons (15.1 liters) | |
SubDrive300 | 8 gallons (30.3 liters) | |
12 gpm and higher (45.4 lpm) | SubDrive15, SubDrive 75 or MonoDrive | 4 gallons (15.1 liters) |
SubDrive20 or SubDrive100 | 8 gallons (30.3 liters) | |
SubDrive30, SubDrive150 or MonoDriveXT | 8 gallons (30.3 liters) | |
SubDrive300 | 20 gallons (75.7 liters) | |
All flows | SubDrive2W | 20 gallons (75.7 liters) |
System Pressure (at Pressure Sensor) | Pressure Tank Setting (±2 psi) |
25 | 18 |
30 | 21 |
35 | 25 |
40 | 28 |
45 | 32 |
50 (Factory Set) | 35 |
55 | 39 |
60 | 42 |
65 | 46 |
70 | 49 |
75 | 53 |
80 | 56 |
Maximum Velocity 8 ft/sec. (2.4 m/s) | |
Min Pipe Dia | Max GPM (lpm) |
1/2" | 4.9 (18.5) |
3/4" | 11.0 (41.6) |
1" | 19.6 (74.2) |
1-1/4" | 30.6 (115.8) |
1-1/2" | 44.1 (166.9) |
2" | 78.3 (296.4) |
2-1/2" | 176.3 (667.4) |