JIS G3461 STB 340 steel tube/pipe

JIS G3461 STB 340 used for exchanger heat on inside and outside of the tube, such as water tubes, smoke tubes, superheater tubes, air preheater tubes, etc. of the boiler, and heat exchanger tubes, condenser tubes, catalyser tubes, etc. used in chemical and petroleum industries. However, it is no applicable to the steel tubes for heating furnace and steel heat exchanger tubes for low temperature service.