Our company Zhangjiagang King Machine Co,Ltd has high demand on the raw materials. We have set up a perfect quality management control system. For each batch of raw materials, we will have them tested by the professional institutions to ensure the raw materials are in accordance with the relevant standards. Below is the testing report of ⌀38 bufferfly valve, outer hexagonal screw, ⌀51 bend and ⌀38 triplet.