This series jacketed ball valves with thermal insulation, cold insulation properties. Designed and manufactured according to GB standard flanges manufactured by 79-94 for the petroleum,chemical, metallurgy, pharmaceutical industry.As a result of the steam valve insulation jacket. So even if the outside temperature is below freezing, the valve is still operational flexibility to ensure pipeline to disconnect, the advantage that general control valve does not have. It is an ideal heavy oil pipeline control valves.