Series 31H Lug valves are drilled and tapped to meet ASME Class 125/150 and PN16 flanges. Series 31H valves are designed for manual operation only. The valve body shall be one-piece lug design with extended neck to allow for 2” of piping insulation, have flange hole drilling per international flange standards and be provided with a non-corrosive bushing and selfadjusting stem seal The valve disc edge and hub on metal discs shall be spherically machined and hand polished for minimum torque and maximum sealing capability.