This valve has precision design, can respond quickly, with extremely small water hammer action but with higher flow speed; Interface is threaded mouth(regular), external part is firstly guided with corner valve, there is self-adjusting seal gland between overflow port and sliding block, valve body corner seat structure can ensure comparatively large flow capacity, extend service lifetime, with characteristics such as being economical, non-maintenance, easy installation and low energy consumption; Dairy products, pharmacy, beer, food, feedstuff, environment protection water treatment, cosmetics and chemical engineering field; .