MODEL 3331 ONE-WAY FLOW

The 3331 is designed to only fill the tank. Tank head (pressure) is sensed under the diaphragm of the 3300 altitude pilot (2). When the tank head falls below the set point , the pilot shifts to vent water from diaphragm chamber of the main valve (1) to drain. This allows the valve to open and fill the tank. When the tank level again reaches the set point, the altitude pilot shifts to apply full inlet pressure to the diaphragm of the main valve, forcing the valve fully closed.

The 3331 consists of the following components, arranged as shown on the schematic diagram:

1. Model 65 Basic Valve Assembly
2. Model 3300 Altitude Pilot
3. Model 141-2 Needle Valve
4. Model 159 Y-Strainer
5. Two Model 141-4 Ball Valves
6. Model 155 Visual Indicator

TWO-WAY ALTITUDE VALVE

The 3333 is designed to drain and fill the tank. When the inlet (system) pressure falls below the set point of the altitude pilot (2), the pilot shifts to vent water from diaphragm chamber of the main valve (1) to drain. This allows the valve to open and let the tank feed the system. When system pressure recovers to a point higher than tank head, the tank will begin refilling. When the tank level again reaches the set point, the altitude pilot shifts to apply full inlet pressure to the diaphragm of the main valve, forcing the valve fully closed.

The 3333 consists of the following components, arranged as shown on the schematic diagram:

1. Model 65 Basic Valve Assembly
2. Model 3300 Altitude Pilot
3. Model 3600 Three-Way Auxiliary Pilot (10-24" only)
4. Model 6401 Two-Way Auxiliary Pilot (10-24" only)
5. Model 141-2 Needle Valve
6. Model 126 Ejector
7. Model 141-1 Check Valve
8. Model 159 Y-Strainer
9. Three Model 141-4 Ball Valves
10. Model 155 Visual Indicator