The high-temperature mixing valves are not standard products, and they are used for sulfur recovery and tail gas treatment. These valves are designed and developed by our company and Qilu Design Institution. They were made in September 1999, and they started to be used in Shengli Refinery, Shanghai Jinshan Petrochemical and Qingyang Petrochemical, up to now they still have good performance and stable quality; they are widely used in refining and petrochemical industry. Our company organized province-level appraisal on June 28, 2001, and obtained the conclusion that“The products are up to the advanced level in the world”. We had applied for the invention patent for them, the patent number: ZL00111165.5.