Rotary valve

A rotary valve comprising:

• a main body provided with a valve chamber for receiving a plate valve, said main body bored with an intermediate hole extending downward from a center of an annular neck of said main body to said valve chamber for positioning a valve rod, said valve rod synchronously disposed in said intermediate hole when said main body is being shaped;
• a seal washer having an outer annular side provided with a serrated surface, said outer annular side of said seal washer combined together with an inner annular wall of said valve chamber of said main body, said seal washer having an inner annular side symmetrically formed with an upper and a lower small flat surface respectively matching with an upper and a lower flat surface of said plate valve, said seal washer having an upper side and a lower side respectively bored with a hole for said valve rod to be inserted therein and fixed with said plate valve;
• and
• a said valve plate received in a valve port of said seal washer and combined with said valve rod.