hengyang valin steel tube co.,ltd.(hereinafter referred to as hyst) was founded in 1958. it is a professional seamless steel pipe manufacturer with great influence in the world. it currently has more than 3,000 employees and total assets of more than 15 billion yuan. it is a national high-tech enterprise, a national new industrialization industry demonstration base, and an outstanding enterprise in the green development of steel. it has successively won the china industry award commendation award, china's excellent steel enterprise brand, and china's outstanding steel enterprise brand.