Danfoss AF-range impulse tube set (OEM designation "Impulse tubes for AFPQ PN40 50"). The impulse tubes connect the diaphragm chamber of a Danfoss self-acting AF-range pressure/flow controller actuator to the pressure-sensing tapping(s) on the pipework, transmitting the pipe pressure to the actuator so it can hold the set differential pressure or flow. This set is matched to the AVPQ controller on valve size DN 50 at PN 40. Tube outer diameter 10 mm; union connection G 1/4; material Stainless steel. Permissible medium: District heating/cooling circulation water. OEM P/N 003G1370. EAN 5702421812204. Technical data quoted verbatim from store.danfoss.com (code 003G1370).