Inspection standard is according to API598 .

The production processes include casting, sand blasting, grinding, machining, painting, assembling and pressure testing.The quality control are excuted in every production process. Any defects will be disposed immediately. All the raw material of pig iron, nodulizer, ferromanganese iron, etc. will be inspected before production. And the parts in each production step are checked by workers themselves and inspected by professional inspectors in the workshops.