Flow control valve having a flow display device observable from any direction

A flow control valve comprising:

• a valve body defining a flow passage, having two opposite ends for connecting with a piping system;
• a valve seat including a combining section installed on a top side of said valve body, an insert section and a display section located between said combining and insert sections, said valve seat defining an axial hole in communication with said flow passage of said valve body;
• a valve rod disposed rotatably within said axial hole in said valve seat, having a coupling portion extending through said insert section of said valve seat and a blocking portion passing through said combining section of said valve seat to extend into said flow passage of said valve body;
• a flow display device installed around said display section of said valve seat, including a plurality of display straps arranged sequentially from top to bottom and each displaying a specific depth of said block portion of said valve rod within said flow passage of said valve body and representing a specific flow rate passing through said flow passage of said valve body, wherein, the higher said display straps represents the smaller extension depth of said blocking portion of said valve rod within said flow passage of said valve body, the larger fluid flow rate through said flow passage in said valve body becomes and wherein, the lower said display straps represents the bigger extension depth of said blocking portion of said valve rod within said flow passage of said valve body, the smaller fluid flow rate through said flow passage in said valve body becomes;
• a transparent cap mounted on said insert section of said valve seat in such a manner to enclose said display section of said valve seat and said flow display device;
• a turning knob attached to said coupling portion of said valve rod for co-rotating around said valve seat in order to adjust an extension depth of said blocking portion of said valve rod within said flow passage of said valve body, which in turn, simultaneously causes idle rotation of said turning knob relative to said transparent cap and adjusting an enclosing extent of said turning knob relative to said transparent cap such that a portion of said transparent cap is exposed from said turning knob to display entire at least one of said display straps of said flow display device, wherein said at least one of said display straps represents an extension depth of said blocking portion of said valve rod within said flow passage of said valve body and corresponding fluid flow rate through said flow passage in said valve body and wherein the topmost one of said display straps exposed from said transparent cap represents said extension depth of said blocking portion of said valve rod within said flow passage of said valve body and said corresponding fluid flow rate through said flow passage in said valve body;
• and
• a positioning ring sleeved around said turning knob and movable between an unlocked position, where said turning knob disengages from said transparent cap such that said turning knob and said valve rod can be rotated arbitrarily relative to said valve seat and causes an axial movement of said valve rod within said axial hole of said valve seat, and a locked position, where said turning knob engages with said transparent cap such that said valve rod is prevented from rotation relative to said valve seat and is prevented from moving axially within said axial hole of said valve seat.