Rotary Seal Feeding Valve

The key and difficult point of the wear-resistant rotary sealing valve is the sealing of the valve. In order to meet the requirements of the sealing VI level, the roughness of the sealing surface is required not more than 0.2 am. As the sealing material of the wear-resistant rotary feeding valve is super-fine crystal cemented carbide, the hardness is high and the brittleness is large, which the ordinary machining cannot achieve. The finishing process of cemented carbide is usually achieved by grinding. The processing steps of the cemented carbide seal face are as follows: wire cutting is used to process the rotary feeding valve to the coarse grinding size; the grinding machine is used to fine grinding the seal surface; the manual grinding method is used to lapping the valve seat with the impeller seal surface to achieve the required surface finish.

Cemented carbide must be rough processed before precision grinding to achieve a certain amount of processing to reduce the workload of fine grinding. The following table is a rough machining method common cemented carbide.

Processing method	Advantages	Disadvantages
Abrasive grinding	Small processing            allowance, high             precision and wide range of processing	High energy                  consumption, easy        burning of workpiece    surface, high surface     residual stress, and self-sharpening of grinding wheels.
Diamond wheel processing	It can process high       hardness materials with high accuracy and low  surface roughness.	Diamond abrasive particles are easy to fall and wear.
Electric discharge machining	There is no cutting         force, no burr and knife marks, and low              requirements for motor materials.	It can not process non- conductive materials,     it has low processing efficiency, high               internal stress and low machining accuracy.

The valve seat design of the rotary feed valve is quite complex and consists many components. The installation of components needs to follow a strict order.

According to the principle of valve seat installation, it need to follow the order that is from inside to outside and from bottom to top. The concrete steps are as follows: first, the installation of the valve seat inner parts, connect the seals with the base, and fix the scrapers on the pedestal with six inner cylinder screws. Then fix the support pin shaft, spring support on the bracket outside the seat. After other parts of the seat are installed completely, make the bracket fit in the seat. And lastly, fix the pad seat on the installed part. After all parts of the valve are fully machined, assemble the valve according to the operation principle of the rotary feeding valve.