This Standard covers requirements for manually operatedmetallic valves in nominal sizes 21?2 (DN 65) through12 (DN 300) having the inlet and outlet on a commoncenterline. These valves are intended for controlling theflow of gas from open to fully closed positions, for usein distribution and service lines where the maximumgage pressure does not exceed 125 psig (8.6 bar). Valveseats, seals, and stem packing may be nonmetallic.