A needle valve is a precision-adjustable valve with a wide range of applications, such as controlling the cutting distance for flame cutting and adjusting the flame temperature with a dial, which are both examples of needle valves. The needle valve is an important component in the measuring pipeline system of instruments, mainly including stop valves and ball valves, whose function is to open or cut off the pipeline passage. The valve core of a needle valve is a very pointed cone, resembling a needle when inserted into the valve seat, hence the name.