I. Quality Requirement
The relevant requirements for valve quality have been set forth in standards.
①The chemical component and mechanical property of the valve’s main materials conform to requirements in relevant material standards.
②The shape and size error of the valve castings meet the regulations in drawings.
③The non-processed surface of the valve castings shall be flat, smooth and free from adhering sand, oxide skin, pore, sand inclusion, cracks or other defects. The typecasting...