During the machining process, attention should be paid to the processing dimensions and surface roughness of each process of the valve fittings, and self-inspection, first inspection, inspection and completion inspection. The surface roughness test for the machining of valve fittings is usually carried out using a suitable roughness specimen comparison test.
At the same time, the size of the valve fittings also needs to be strictly tested. The gauges used in the inspection are: when the linear tolerance zone is equal to less than 0.1 mm, the inner diameter dial gauge, the inner diameter micrometer and the outer diameter micrometer should be used. When the gauge is larger than 0.1 mm, the gauge is used. Vernier calipers, vernier depth calipers, and vernier height gauges with an accuracy of at least 0.02 mm. A steel ruler can be used when the linear tolerance band is equal to greater than 1 mm.
In addition, the inner groove inspection of the valve fittings should be measured with a special gage or with CNC machine tools. The dovetail slot is measured in a simple manner using a 2 equal diameter cylinder with a micrometer to measure its width. The dovetail taper is mainly guaranteed by tools and processes. The thread of the valve fitting can be tested with the corresponding precision thread plug gauge and ring gauge, and the special plug gauge and card can be inspected.http://www.dmgcastings.com/