To remove orifice plates loosen all studs and remove the top half of the studs. Spread flanges by turning the jackscrews clockwise. Remove orifice plate for inspection or replacement.

To install orifice plates replace orifice plate and gaskets between flanges. Release the flanges by turning two jackscrews counterclockwise. Replace all studs. Retighten studs starting with two studs opposite each other.