Patent ID: 8602054

Claim:
A device comprising part of a system for measuring differential pressures in a fluid system, the device comprising: a valve assembly ( 1 ) including a valve body ( 7 ) with first and second connections ( 13 , 14 ) for connection to the fluid system, ducts ( 32 , 33 ) for communication with a differential pressure sensor ( 12 ) for registration of the differential pressure, a first cavity ( 22 ) in communication with the ducts ( 32 , 33 ), where the first cavity ( 22 ) includes a calibration spool ( 10 ) which is displaceable in the first cavity ( 22 ) between a measure position and a position for zero point calibration/flushing of the valve assembly ( 1 ), the calibration spool ( 10 ) separating the differential pressure sensor ( 12 ) from the fluid system when the calibration spool ( 10 ) is in its initial position, and the calibration spool ( 10 ) including sealing elements ( 27 ), which prevent fluid communication between the ducts ( 32 , 33 ) and the first cavity ( 22 ), wherein the valve assembly ( 1 ) includes a second cavity ( 15 ) with a safety valve spool ( 8 ), the safety valve spool ( 8 ) protects the differential pressure sensor ( 12 ) against an excessive differential pressure since the safety valve spool ( 8 ) is arranged to be displaced, by differential pressures higher than a dimensioned value, in a direction towards a low pressure side and, as a result, opens a passage between a high pressure side and the low pressure side, formed between the first connection ( 13 ) and the second connection ( 14 ), via the second cavity ( 15 ) in the valve body ( 7 ) and via cavities ( 24 ) and recesses ( 25 ) provided in the safety valve spool ( 8 ) so that a pressure equalizing occurs.