After the design of the valve block is completed, the processing and subsequent treatment are carried out

2021-07-05 09:14:33

After the design of valve block, the process is as follows:

1) Pre processing. The material processed by valve block shall be kept dense in structure, and there shall be no defects such as interlayer and sand hole. The blank shall be inspected before processing. Cast iron blocks and larger steel blocks should be aged and pretreated before processing.

2) Blanking. Generally, at least 2mm machining allowance shall be reserved for each side.

3) Milling profile. Milling 6 sides of valve block, leaving 0.2-0.4mm rough grinding amount on each side.

4) Rough grinding. The grinding valve block has 6 sides, each side is left with 0.05-0.08mm fine grinding quantity, so as to ensure that the parallelism of each pair of corresponding surfaces is less than 0.03mm, and the verticality of two adjacent surfaces is less than 0.05mm.

5) Scribe. If possible, it can be directly completed by center drilling on the CNC drilling machine.

6) Drilling. The surface roughness of each hole is Ra12.5.

7) Fine grinding. Grind 6 surfaces of the valve block to a roughness of ra0.4um.

8) Deburring and cleaning. In order to keep the hydraulic system clean, the valve block needs to deburring. At present, many manufacturers still use brush for manual deburring, but also use methane blasting method for deburring. After deburring of valve block, it is necessary to pass endoscope inspection to ensure that burr is cleaned. After that, clean the valve block. Clean up various particulate pollutants, corrosion, grease, etc. attached to the valve block surface.

9) Surface rust proof treatment. In order to ensure that the valve block will not rust too early in use, the valve block manufacturer needs to carry out rust prevention treatment. The inner oil channel of valve block can be pickling and phosphating. The rust prevention treatment process on the outer surface mainly includes blue, cadmium plating, zinc plating, nickel plating and other surface treatment.

10) The pressure maintaining test shall be conducted on the valve block according to the design requirements. The safety coefficient of valve block is different for different system working pressure: the working pressure is less than 16MPa and the test pressure is 1.5 times; The working pressure is less than 25MPa, and the test pressure is 1.25 times; The working pressure is less than 31mpa and the test pressure is 1.15 times. The pressure holding time of the test is 5-10min, and there shall be no leakage at each sealing surface and joints.