| 摘要 |
PURPOSE: A valve with a recessed groove and a rising stem ball valve are provided to reduce the driving torque for driving a lower stem and to increase durability by reducing the abrasion between grooves and coupling units. CONSTITUTION: A valve with a recessed groove comprises a stem(12) and coupling units(SP). The stem operates a ball of the valve or a plug. The coupling units are coupled to grooves(12b) formed on the stem to determine the motion of the stem. The grooves are formed on the surface of the stem and the depth of the grooves is lower than the thickness of the stem. |
