Pneumatic valve material shape size deviation inspection

pneumatic valve casting or forging blank shape are technical standard or drawing size requirement, casting because of the error model size deviation, the deviation of sand mold, the core floating etc when casting and casting shape, size out-of-tolerance. Forgings are for die forging wrong side, forging ratio. Billet size less than improper mould appearance is not complete, free forging forming deviation, etc. The shape size more than technical standard or drawing size is also a table and defects. , big can check marking way. Except _ 7 above material surface defects, pneumatic valve and the surface of the casting defects in raw materials, such as: size inside and outside more than the standard deviation; Surface adhering sand, sand inclusion, without meat, carinate bulge ( More meat) Can be in accordance with the requirements for quality of the material list and pay attention to inspect the defects. Material list and defect inspection should be paid attention to in order to 'F: ( ） ! Should be defects in the original position after several strict review, the fastening parts for high pressure pneumatic valve, pressure components and pneumatic safety valve spring should be adopted such as magnetic particle inspection or dye check. ( ） The material surface defects during the machining parts, must keep clear defects, clear away the correct process method should be adopted to prevent defects to expand or to deepen. Clear defects of excessive surrounding should be smooth, clear the depth of the defects should be completely place in addition to the thickness of the material after not less than the negative deviation stipulated in the standard. Pressure parts for NDT inspection. ( ） In special cases' F, BuShu material surface defects allowed to adopt the method of repair welding for save, but must have the strict repair welding of mature! Two arts and approved by the technical director, carried out by qualified welders repair welding, should be the reliable NDT inspection after repair welding.