... 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 ... of valve type orifice throttle device. 6,Can replace and maintain orifice plate, little space required, high ... sulphur resistant type. Advanced Type Orifice Plate Pressure Device