... is optional, for DN400 and above, have special requirements need to reserve.-PT0: None-PT1000-A-B: Pt1000 temperature sensor The A ... means the type of temperature sensor: 2: 2-wire4: 4-wire The ... for heating and cooling, high temperature type, nominal size of DN200, operating pressure of less than 1.6Mpa, 5-channel flowmeter, Pt1000 sensor ...