... than Grade 0.5. 3,ENP on orifice plate, guide plate, etc trims, prefect corrosion resistance and abrasive ... 4,Aviation rubber for seals ring of orifice plate, made through integrated pressuring, good corrosion resistance ... throttle device. 6,Can replace and maintain orifice plate, little space required, high cost performance, reliable ... sulphur resistant type. Advanced Type Orifice Plate Pressure Device