CERTIFICATION:ANAB,KAS,THE AAA CLASS STANDARD OF INTERATIONAL QUALITY CREDIT RATING CLASSLICATION,FAMOUS BRAND OF CHINA.DESIGNLC We just produce perfect products.I am professional, I am well. 1).THE FUNCTION:sub- cylinder is also called points drum,It is essential ancillary equipmentto steam boiler.The main Mainly used for steam lane dredge in oil chemical, generate electricity, steel , cement, ...