Why do you use jackscrews on orifice flanges?

Jackscrews are used on orifice flanges primarily to facilitate the alignment and separation of the flanges during maintenance or inspection. They allow for precise adjustments to ensure proper spacing and alignment of the flange surfaces, which is crucial for accurate flow measurement. Additionally, jackscrews help avoid damage to the orifice plate and ensure a tight seal when reassembling the flanges.