The 321 Series (7321B) is a normally closed 2-port pilot operated solenoid valve. It connects to water, hot water and oil lines in sizes 3/8" to 2", with orifices of 13 to 50 mm.
| Working Fluid | Water / hot water / oil |
| Actuation Type | Pilot operated, 2-port normally closed |
| Connection Size | PF 3/8" to 2" |
| Orifice Size | 13 to 50 mm |
| Flow Rate | Kv 50 to 620 |
| Operating Pressure Differential | 0.1 to 20 bar (1-1/4" to 2": 0.1 to 10 bar) |
| Fluid Temperature | 90 °C or less (H-1F coil), 120 °C or less (H-1H coil) |
| Ambient Operating Temperature | -10 to 50 °C |
| Seal Material | FKM (3/8" to 1") / NBR (1-1/4" to 2") |