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High resolution low pressure control is critical to a good part in the low pressure aluminum casting process. A Proportion-Air QB2 air pressure control valve is piloting an R-Series slave regulator for low pressure aluminum shot control. The calibrated range is 0-15 psig. There is a second pressure transducer plumbed into the gauge port of the R-Series regulator and its signal is taken back to the QB2. With this control arrangement, the QB2 can compensate for the regulator’s spring hysteresis and achieve a repeatability of +/-0.02% of full scale calibration. Resolution is +/-0.2% of full scale calibration.
This sketch shows A QB2 pressure control valve piloting a high pressure ratio regulator. The maximum calibrated range of the assembly is 0-5000 psig. The DSTY 5000 senses pressure downstream and provides feedback to the QB2. The QB2 compares the command signal with feedback from the DSTY for high accuracy pressure control. The QB2’s calibration is 0-70 psig (the ratio regulator has a 72:1 ratio between dome pressure and downstream pressure).
A QB3 air pressure control valve is providing pressure to a vehicle’s air bags to control ride height. Each air bag has an independent 2-way valve that can be opened and closed individually. This allows the operator to inflate/deflate all bags at the same time or independently. The QB3 can be modified to work with a vehicle’s 12Vdc system.