China's chemical trade deficit is expanding

The industry economic operation report just released by the China Petroleum and Chemical Industry Federation shows that from January to November, the total import and export trade volume of the industry reached US$ 551.8 billion, an increase of 33.6% year-on-year. Among them, the import of.......

Screw pump hydraulic anti-reversing technology

Screw pump hydraulic anti-reversing technology is to prevent the conventional screw pump wells in the shutdown or card pump column reversal, resulting in off the rod, polished rod rejection bending, ground equipment damage and other issues of technology.

Screw rod .......