We recently delivery a lot fully welded ball valves to an overseas client, these ball valves will use for a district heating plant in a cold place for warming. The ball valves pressure is PN25 or PN40, size from DN200-DN800. All use worm gear operation.  Our fully welded ball valves product for district heating size can be DN15-DN1400, pressure PN16-PN40.   We can also produce fully welded ball valves for natural gas with high pressure like 600LB(PN100), 900LB(PN160).