Inspection Procedure for Spares of Centrifugal Compressors Upon Arrival at a Company

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1 General Provisions 1.1 Scope of Application These specifications are applicable to the inspection of spare parts for centrifugal compressors in production facilities (such as rotor assemblies, diaphragm assemblies, bearings, couplings, sealing components, non-metallic spare parts, etc.), providing a basis for the inspection of such spare parts. 1.2 Referenced standards: GB/T 16941—1997 “Design, Manufacturing Specifications and Data Sheets for Turbocompressors Used in Process Industries”; JB/T 4113—2017 “Integral Gear-Driven Centrifugal Air Compressors”; JB/T 6443—2002 “Centrifugal Compressors”; HG25745—93 “Technical Specifications for the Inspection of Centrifugal Compressor Rotors”; HG25744—93 “Technical Specifications for the Inspection of Hydraulic Couplings”; HG25743—93 “Technical Specifications for the Inspection of Tilting-Pad Bearings”; GB6557—2009 “Mechanical Balancing of Flexible Rotors”; GB3852—2017 “Types and Dimensions of Coupling Shaft Holes and Keyways”; JIS B 1453-1988 “Gear Couplings”; GB/T 13275—91 “Technical Requirements for General-Purpose Centrifugal Ventilators”; API—672 “Integral Gear-Driven Multi-Shaft Centrifugal Air Compressors for General Oil Refineries”; API—614 “Special Lubrication, Shaft Sealing, and Control Oil Systems”; API—671 “Couplings for Special Purposes in Oil Refineries”; API—617 “Axial Flow Compressors, Centrifugal Compressors, and Expander-Compressors for the Petroleum, Chemical, and Gas Industries”; JB1581–1582-2014 “Ultrasonic Testing Methods for Turbine, Turbogenerator Rotors and Shafts, as well as for Turbine Impellers”; GB1800–1804-79 “Tolerances and Fits”; GB1182–1184-80 and GB1958-2017 “Tolerances for Shape and Position”; JB 4730-2015 “Non-Destructive Testing of Pressure Vessels”; JB/T 5439-2017 “Ultrasonic Testing of Ductile Iron Parts in Compressors”; JB/T 5440-2017 “Ultrasonic Testing of Forged Steel Parts in Compressors”; JB/T 5441-2017 “Ultrasonic Testing of Cast Steel Parts in Compressors”; JB/T 5442-2017 “Magnetic Particle Testing of Critical Parts in Compressors”. 1.3 Inspection and evaluation criteria: 1.3.1 The dimensions and precision requirements specified in the manufacturing drawings of equipment components, as well as the requirements outlined in the technical specifications. 1.3.2 The contents and requirements specified in the technical annex to the contract. 1.3.3 Standards referenced in clause 1.2. 2 Inspection Contents 2.1 Rotor Assembly 2.1.1 Document Review 2.1.1.1 Check whether the product documents are complete as required by the contract. 2.1.1.2 Review whether the product quality documents, certificates of conformity, and technical documents (such as reports on the chemical composition of component materials, mechanical property test reports, hardness test reports, heat treatment reports, non-destructive testing reports, dynamic balance reports, etc.) meet the relevant specifications, standards, and requirements specified in the drawings. 2.1.2 Inspection steps upon arrival 2.1.2.1 Visual inspection a) The surface of the rotor assembly shall be free from defects such as cracks, dents, damage, or scratches ； The machined surface should be flat and smooth. b) The shaft sleeve should be secure, and the comb-tooth seal should be free of breaks or deformation ； The impeller flow channel should be smooth with no foreign objects. 2.1.2.2 Geometric dimension inspection: Measure all dimensions, and the dimensional tolerances shall meet the requirements specified in the drawings. 2.1.2.3 The values of form and position tolerances shall meet the requirements specified in the drawings or the following requirements: 2.1.2.4 For flaw detection, ultrasonic testing and dye penetrant testing of the shaft journals shall show no defects that would affect their usability. Perform a residual magnetism check on all rotating parts of the rotor assembly; the residual magnetism level should not exceed 0.0005 Tesla (5 gauss). 2.1.2.5 Hardness inspection: The parts shall be subjected to a hardness inspection, and the hardness values must meet the requirements specified in the drawings. 2.1.2.6 Chemical composition inspection: Re-test the chemical composition if necessary. 2.1.2.7 Metallographic inspection: When necessary, a metallographic repainting inspection shall be carried out, and its structure and grain size shall meet the technical requirements. 2.2 Partition Component 2.2.1 Document Review 2.2.1.1 Check whether the product documents are complete as required by the contract. 2.2.1.2 Review whether the product quality documents, certificates of conformity, and technical documents (such as reports on the chemical composition of component materials, reports on mechanical property tests, hardness test reports, heat treatment reports, non-destructive testing reports, etc.) meet the relevant specifications, standards, and requirements specified in the drawings. 2.2.2 Inspection upon arrival 2.2.2.1 Macroscopic inspection a) Check whether the components are deformed; their surfaces should be smooth without scratches, and the joints should be smooth as well, free from defects such as cracks, delamination, pores, or inclusions. b) The horizontal mid-surface should be smooth, flat, and gap-free, with the surfaces fitting closely together; the maximum gap at the joint should not exceed 0.05 mm. c) The surface roughness of the mating surfaces shall meet the requirements specified in the drawings. 2.2.2.2 Geometric dimension inspection: The measured values of all fitting and positioning dimensions shall be within the tolerance ranges specified in the design drawings. 2.2.2.3 For surface coloring flaw detection of inspection components, no defects that affect operational requirements shall be present. 2.2.2.4 The hardness inspection component shall be subjected to a hardness test, and the hardness value shall meet the requirements specified in the drawings. 2.2.2.5 Chemical composition inspection: Re-test of the chemical composition is conducted when necessary. 2.3 Radial Bearings 2.3.1 Document Review 2.3.1.1 Check whether the product documentation is complete as required by the contract. 2.3.1.2 Review whether the product quality certification documents, certificates of conformity, and technical documents (such as reports on the chemical composition of component materials, reports on mechanical property tests, and non-destructive testing reports) meet the requirements of relevant specifications, standards, and drawings. 2.3.2 Inspection upon arrival 2.3.2.1 Macroscopic inspection a) Remove the bolts securing the mid-surface of the tile shells; check that the flatness of the mid-surfaces of the upper and lower tile shells meets the requirements specified in the drawings, and that the positioning pins fit tightly together. After tightening the mid-surface bolts, the mid-surface should show no cracks; a 0.02 mm feeler gauge must not be able to fit into it. b) The bushing babbitt should be free of defects such as cracks, chipping, or roughness, and it should fit well. c) The load-bearing surface on the back of the tile should be smooth, and it should maintain even contact with the tile shell along the axial direction; the tile that swings around the pivot should fit tightly with the pivot pin without any looseness. The tiles move freely within the tile casing without getting stuck. d) Tiles with thermistors, where the thermistors are firmly fixed to the tiles without any looseness, and the insulation covering of the leads is in good condition. After assembly, the thermosensitive element and leads should not prevent the tile from moving freely within the tile housing. 2.3.2.2 Inspection of geometric dimensions and form and position tolerances a) Measure the outer diameter of the bearing housing; its dimensions, roundness, and cylindricity should conform to the drawings. b) The bearing clearance measured using the tile-lifting method on the dummy shaft (or the spare rotor journal) shall meet the technical requirements. c) Measure the thickness of the bearing shells; the difference in thickness among shells of the same bearing should be less than 0.01 mm. 2.3.2.3 For flaw detection, surface coloring inspection is required for the tiles, and the babbitt alloy should fit well. 2.4 Thrust Bearings 2.4.1 Document Review 2.4.1.1 Check whether the product documents are complete as required by the contract. 2.4.1.2 Review whether the product quality certification documents, certificates of conformity, and technical documents (such as reports on the chemical composition of component materials, reports on mechanical property tests, and non-destructive testing reports) meet the requirements of relevant specifications, standards, and drawings. 2.4.2 Inspection Steps upon Arrival 2.4.2.1 Macroscopic Inspection a) The load-bearing surface on the back of the thrust bearing pads should be smooth; the babbitt material should be free from defects such as cracks, chipping, or roughness, and the babbitt should adhere well to the pads. b) The bearing surface of the pressure equalizing block should be smooth, and it should move freely within the base ring without any jamming. The voltage equalizing blocks can swing freely. c) The base ring shows no cupping deformation, and the joint surface between the two halves of the base ring is smooth with no gaps. d) Tiles with thermistors, in which the thermistors are firmly fixed to the tiles without any looseness, and the insulation covering of the leads is in good condition. 2.4.2.2 Geometric dimension inspection a) The outer diameter and thickness of the thrust bearing, etc., shall conform to the drawings. b) Measure the thickness of the bearing shells; the difference in thickness between shells in the same set should be less than 0.01 mm. 2.4.2.3 For flaw detection, the surface of the tiles shall be inspected by coloring testing, and the babbitt alloy shall adhere well. 2.5 Coupling Assembly 2.5.1 Document Review 2.5.1.1 Check whether the product documents are complete as required by the contract. 2.5.1.2 Review the product quality certification documents, certificates of conformity, and technical documents (such as reports on the chemical composition of component materials, reports on mechanical property tests, hardness test reports, non-destructive testing reports, and reports on dynamic and static balance tests) to ensure that they meet the requirements of relevant specifications, standards, and drawings. 2.5.2 Inspection upon arrival 2.5.2.1 Visual inspection a) Check whether the internal and external threads of all bolts and nuts are in good condition; the fit between bolts and nuts should be just right ； The fit between the bolt and the hub bolt hole should not be loose. b) The inner surface of the hub bore shall be free from scoring or damage, and the area where the O-ring fits shall have no grooves; the surface roughness shall be Ra0.4. c) Check the contact between the hub and the red lead at the end of the spare rotor shaft; the contact area should be over 85%, with no hard contact points or areas where there is no contact at all. d) The flange connection surfaces of the internal toothed sleeve and the intermediate coupling tube should be flat; after the connection bolts are installed, there should be no gaps at the joint surfaces, and the shoulders should not be loose or wobble. The contact area in the height direction of the internal and external teeth should be no less than 75%. e) For diaphragm couplings, it is also necessary to check whether the transition sleeve and the bolts securing the diaphragm are in good condition. 2.5.2.2 Geometric dimension inspection: Measure all dimensions, and the dimensional tolerances shall meet the requirements specified in the drawings. After the O-rings and backup rings are placed in the end ring groove of the spare rotor shaft and the hub ring groove, the compression amount of the O-rings on each side should be within 0.5–0.6 mm, while the backup rings should be 0.1–0.2 mm below the O-ring groove. 2.5.2.3 Geometric tolerance inspection a) All values shall meet the requirements of the drawings. b) The circularity error of the intermediate cylinder body is less than 0.05 mm. The parallelism between the two working surfaces is less than 0.03 mm. 2.5.2.4 Flaw detection inspection a) Bolt magnetic particle testing shall show no defects. b) The surface coloring inspection of the coupling shall be defect-free. 2.6 Floating ring seal assembly 2.6.1 Document review 2.6.1.1 Check whether the product documents are complete as required by the contract. 2.6.1.2 Review the product quality certification documents, certificates of conformity, and technical documents (such as reports on the chemical composition of component materials, reports on mechanical property tests, hardness test reports, non-destructive testing reports, etc.) to ensure that they meet the requirements of relevant specifications, standards, and drawings. 2.6.2 Inspection upon arrival 2.6.2.1 Visual inspection a) Check the outer surface of the floating ring seal for any defects such as cracks, as well as any scratches or damage on the sealing surface. The end face of the floating ring should be flat, the pin holes should be aligned, and the length of the pins should be appropriate. b) The babbitt layer on the inner circular surface of the floating ring shall be free from defects such as scratches and delamination. The axial contact surfaces between the floating ring and the housing should be inspected with red lead to ensure even contact, and the floating ring must not exhibit any axial deformation. c) Check the “O” ring for defects such as burrs, scratches, aging, etc. 2.6.2.2 Geometric dimension inspection: Measure the dimensions of all parts of the floating ring seal; the dimensional tolerances shall meet the requirements specified in the drawings as well as those listed below. a) The axial clearance of the floating ring within the floating box shall not exceed 0.15 mm, and the difference in the axial thickness of the floating ring along its entire circumference shall not exceed 0.01 mm. b) The radial clearance of the inner ring of the floating ring seal is 0.051～0.076 mm, the radial clearance of the middle ring is 0.140～0.165 mm, and the radial clearance of the outer ring is 0.102～0.127 mm. 2.6.2.3 The flaw detection requirement is that the babbitt layer on the sealing surface and the inner circular surface of the floating ring shall be free of defects upon dye penetrant inspection. 2.7 Non-metallic spare parts (mainly O-rings and back rings) 2.7.1 Document review 2.7.1.1 Check whether the product documents are complete as required by the contract. 2.7.1.2 Review the product quality certification documents, certificates of conformity, and technical documents (such as reports on the chemical composition of component materials and reports on mechanical property tests) to ensure that they meet the requirements of relevant specifications, standards, and drawings. 2.7.2 Inspection upon arrival 2.7.2.1 Visual inspection – Check for defects such as crushing, warping, burrs, scratches, aging, cracks, etc. It should also have good elasticity. 2.7.2.2 Geometric dimension inspection: Measure all dimensions, and the dimensional tolerances shall meet the requirements specified in the drawings. After the O-rings and backup rings are placed in the end ring groove of the spare rotor shaft and the hub ring groove, the compression amount of the O-rings on each side should be within 0.5–0.6 mm, while the backup rings should be 0.1–0.2 mm below the O-ring groove. 2.7.2.3 Physical property inspection: As necessary, tests such as hardness, impact value, and aging tests should be conducted. 2.7.2.4 Chemical composition inspection: Re-test the chemical composition if necessary. 3 Manufacturer inspection and on-site testing: The on-site testing requires, as stipulated in the contract, that the buyer send qualified technical personnel to the manufacturer to conduct quality inspections of the materials, manufacturing process, assembly, and testing procedures for important components such as the compressor rotor and mechanical seals. The focus is on obtaining on-site verification of critical, patented, precise, and non-reproducible items for which internal inspection at the delivery site is not feasible. 3.1 Pressure resistance tests and sealing tests for components such as machine seals ； Over-speed tests of the impeller, etc ； 3.2 Component tests such as rotor dynamic balance test and operation test ； 3.3 Other specified test items. 4 Handling of spare parts that do not meet the inspection and evaluation standards: Spare parts that are found to not satisfy the evaluation standards during unboxing on site or other inspection processes must be carefully documented, and submitted to the supplier for verification. If it is the supplier’s responsibility, the spare parts should be returned or a claim should be made in accordance with the contract provisions. 5 Management of spare parts records: To improve the management of spare parts records, after the incoming spare parts have been inspected, the relevant personnel should fill out the \"Mechanical Parts Inspection Report upon Arrival\". This report is in two copies, to be kept by the testing unit and the user unit respectively.