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Testing standards for the overall connection part of the equipment
Wrong mouth detection
The pipeline and flange are perpendicular, but not concentric. If the bolt hole diameter and bolt diameter meet the standards, the bolt can be freely inserted into the bolt hole without using other tools, which is considered qualified.
Mishole detection
The pipeline flanges are concentric, but there is a significant deviation in the chord distance (or diameter of the bolt hole center circle, etc.) between the corresponding bolt holes of the two flanges. It is necessary to check whether the deviation meets the relevant requirements.
Mouth opening detection
The flange clearance is too large, and it is necessary to check whether the allowable opening value between the two flanges (excluding the pre tension value of the pipeline and the thickness of the gasket or blind plate) is within a reasonable range.
Side mouth detection
Pipelines are not perpendicular, concentric, and flanges are not parallel. The allowable deviation values between the two flanges are as follows: when using non-metallic gaskets, it should be less than 2mm; when using semi metallic gaskets, elliptical gaskets, octagonal gaskets, and flanges connected to equipment, it should be less than 1mm.
Testing standards for various accessories
Pump head, pump casing, and auxiliary impeller
Auxiliary impeller: Clean and inspect the auxiliary impeller, and there should be no defects such as wear, cracks, erosion, etc.
Sealing ring surface: There should be no pits, scars or grooves on the sealing ring surface of the pump head and pump casing, and the maximum allowable surface roughness Ra is 0.8 μ m. The assembly clearance between the sealing ring and the pump head and pump casing should be 0.05-0.10mm, and the sealing ring should not be loose.
Bounce value: According to the joint between the pump head and pump casing, the radial runout value of the sealing ring inner hole should not exceed 0.50mm, and the end face runout should not exceed 0.04mm. The gap between the pump head, pump casing sealing ring, and assembly sealing ring should be measured between 0.50 and 0.60mm.
impeller
Surface inspection: Clean and inspect the surfaces of all levels of impellers, and there should be no defects such as cracks or wear on the impeller surface. The surface of the impeller flow channel should be smooth, free of dirt and burrs, and the blades should have no defects such as cracks, erosion thinning, etc.
Sealing ring inspection: Check the sealing rings at the inlet and outlet of the slurry pump impeller at all levels, and there should be no looseness. The surface of the sealing ring should be smooth and free of burrs. The maximum allowable value for surface roughness Ra is 0.8 μ m, and the gap between the impeller and the assembly should be 0.05-0.10mm. According to the inner hole of the impeller, the radial runout should not exceed 0.05mm, and the end face runout should not exceed 0.04 mm.
Coordination inspection: The impeller and shaft adopt an interference fit, usually H7/h6. The interference range between the key and keyway is 0.09-0.12mm. After assembly, the clearance between the key tops is 0.04-0.07mm. The impeller must be balanced.
Pump shaft
Appearance inspection: Clean and inspect the pump shaft, which should be free of defects such as cracks and severe wear. If there is wear, cracks, erosion, etc., they should be recorded in detail and the reasons analyzed.
Straightness inspection: Check the straightness of the pump shaft, which should not exceed 0.05mm throughout the entire length. There should be no defects such as pits or grooves on the surface of the shaft neck.
Parallelism check: The parallelism error between the centerline of the keyway and the centerline of the shaft should be less than 0.03mm/100.
Industry standards
The national standard for wear-resistant slurry pumps adopts the mechanical industry standard JB/T8096-2013 of the People's Republic of China. This standard specifies the types and basic parameters, technical requirements, test methods, inspection rules, etc. of centrifugal slurry pumps, and is applicable to pumps that transport liquids containing suspended solid particles (such as ore, ash, coal slurry, mud sand, and gravel). At the same time, a series of relevant documents were also cited, such as GB/T699 High quality Carbon Structural Steel, GB/T985.1 Recommended Groove for Gas Welding, Shielded Metal Arc Welding, Gas Shielded Welding, and High Energy Beam Welding, which standardized the materials, welding, inspection, and other aspects of slurry pumps. The national standard wear-resistant slurry pump is a single-stage, single suction axial suction pump, which is divided into three structures according to the pump structure and pump axis direction: horizontal double shell pumps with inner and outer shells. The inner shell materials are divided into three categories: metal, rubber, and other non-metallic materials. Inner shells of different materials should be interchangeable within the same shell. At present, most wear-resistant components in China are made of high chromium cast iron, which has a casting hardness of up to 65HRC and is one of the high-performance wear-resistant materials. It has a large alloy content and complex production process, and has been applied in China since the 1980s.
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