Flow rate control valve

A flow rate control valve comprising:

• a body defining a fluid passage, a valve chamber, and a valve seat;
• a tubularly-shaped bonnet supported on said body aligned with said valve seat;
• a stem supported by said tubularly-shaped bonnet and positioned in a passage of said bonnet so as to be aligned with said valve seat, said stem being movable along a length axis of said stem toward and away from said valve seat and being rotatable about said length axis;
• a handle affixed to an outer end of the stem and enclosing an outer circumferential surface of the bonnet for rotating said stem;
• a lock screw threadably mounted in said handle for selectively locking to said bonnet and thereby locking the handle against movement relative to the bonnet;
• wherein said handle comprises a handle main body affixed to the upper end of the stem and a tubular lock handle enclosing the upper outer circumferential surface of the bonnet, said lock handle being coupled to said handle main body by a coupling means between the lock handle and main body for allowing said lock handle to be moveable in a direction orthogonal to the length axis of the stem relative to said main body but, for preventing said lock handle from substantially rotating about and moving along said length axis relative to said main body, and wherein said lock screw, when screwed to selectively lock said lock handle to said bonnet is moved in a direction substantially orthogonal to the length axis of the stem to thereby lock said stem against rotation and linear movement about and along said length axis said stem while is not substantially moved orthogonal to said length axis, even if said lock handle is thereby moved orthogonal to said length axis.