AAK customizes hydraulic manifold blocks for customers in multiple countries, including Germany, the United States, Russia, and Israeli military clients.
We strictly control the selection of materials, processing techniques, surface treatment, cleaning, and inspection to ensure the reliability and longevity of hydraulic manifold blocks like below:
1. Materials and Pretreatment
1) Material Selection
l The valve block material should have a dense structure and be free of defects such as sand holes and interlayers. If necessary, non-destructive testing should be carried out.
l If forging blanks are used, they need to undergo normalizing treatment to eliminate internal stress and non-destructive testing.
2) Pretreatment
l Cast iron or large steel parts require aging treatment or pretreatment.
2. Machining process
1) Surface processing
l The surface roughness of the hydraulic valve block must meet the design requirements, and the installation surface (such as the contact surface of hydraulic valves and pipe joints) must not have scratches to prevent leakage
l Rough machining requires reserved precision grinding allowance, and the surface roughness Ra value after precision machining should meet the accuracy requirements.
2) Chamfering and deburring
l Edge chamfer 2 × 45 ° (small valve body chamfer × 45 °), keep the oil passage hole sharp and remove burrs.
l All flow channels (especially intersections) need to be thoroughly cleaned of burrs to avoid residual effects on system stability.
3. Surface treatment and rust prevention
1) Coating and Marking
l The surface can be plated with electroless nickel, with a thickness controlled between 0.008-0.012mm.
l Steel seal markings should be placed next to each oil port, with a distance of ≥ 6mm from the hole opening, to avoid affecting the sealing performance.
2) Rust prevention measures
l After processing, rust and dust prevention treatment should be carried out, and sealed and stored in a clean and dry environment.
4. Cleaning and assembly
1) Cleaning
l Before assembly, the manifold block should be thoroughly cleaned using rust proof cleaning solution or kerosene/engine oil to ensure that blind holes and flow channels are free of iron filings and impurities.
l Maintain pressure during flushing, and switch the solenoid valve to flush all channels.
2) Assembly
l Check if the connectivity of the ducts is consistent with the schematic diagram, ensuring that the seals and components are all qualified products.
l When using anaerobic adhesive to seal screws, it is necessary to clean the joint surface and let it stand for 24 hours before applying oil.
5. Inspection and Testing
1) Inspection
l After processing, it is necessary to check the dimensional accuracy of oil ports, threads, counterholes, etc. Steel parts should be electroplated/blackened, and aluminum parts should be anodized for rust prevention.
l The clearance between the valve spool and the valve hole is 0.005-0.035mm, with a tolerance of 0.002-0.008mm for roundness/cylindricity.
2) Performance Testing
l Before debugging, the circuit needs to be flushed for 10-20 minutes to verify reliability through withstand voltage testing and functional testing.
Based on the above materials, processing, surface treatment, and inspection process specifications, the functionality and durability of the hydraulic manifold blocks produced by AAK is ensured.
AAK HYDRAULIC VALVES (842) 2025-03-05
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