Today, Xiaobian will talk to you about the knowledge of valve material
1. The material of the valve body should be mainly ductile iron, and the grade and the actual physical and chemical test data of cast iron should be indicated.
2. The stem material should strive for stainless steel stem (2CR13), and the large-diameter valve should also be a stainless steel embedded stem.
3. The nut material is made of cast aluminum brass or cast aluminum bronze, and the hardness and strength are greater than that of the valve stem.
4. The hardness and strength of the stem bushing material should not be greater than that of the valve stem, and there should be no electrochemical corrosion with the valve stem and valve body under water immersion.
5. The material of the sealing surface
(1) The valve category is different, and the sealing method and material requirements are different;
(2) For ordinary wedge gate valves, the material, fixing method and grinding method of the copper ring should be explained;
(3) Physicochemical and hygienic testing data of soft seal gate valve and valve plate lining material;
(4) The butterfly valve shall be marked with the material of the sealing surface on the valve body and the material of the sealing surface on the butterfly plate; Their physical and chemical test data, especially the hygienic requirements, anti-aging performance, and wear resistance of rubber; Usually use nitrile rubber and EPDM rubber, etc., and it is strictly forbidden to mix with reclaimed rubber.