Jiangsu Haifa Machinery Manufacturing Co., Ltd.

In petroleum, petrochemical, and natural gas installations, centrifugal pumps are typically in continuous operation, handling complex media and experiencing significant fluctuations in operating conditions. API 610 / ISO 13709 specifies vibration limits for pump units, essentially to ensure sufficient operational stability, reliability and service life within the specified operating range. Therefore, when responding to vibration requirements, pump manufacturers should not only control vibration values during the testing phase but must manage the entire process, including hydraulic design, rotor design, bearing support, sealing system, baseplate rigidity, and manufacturing and assembly. First, attention should be paid to hydraulic stability of the pump The hydraulic design of the impeller, volute, or diffuser should ensure stable operation within the preferred operating range, avoiding issues such as increased radial forces, flow recirculation, cavitation, and pressure pulsation caused by operating too far from the best efficiency point. During selection, the rated point should be as close as possible to the best efficiency point, and prolonged operation at the minimum or maximum flow boundary should be avoided. For high-head, high-speed, or low-flow pumps, special attention must be given to net positive suction head (NPSH), impeller inlet velocity, and suction conditions to prevent cavitation-induced vibration exceeding limits. Second, rotor system design is key to vibration control. The pump shaft must have sufficient rigidity, with reasonable shaft diameter, span, impeller arrangement, and coupling weight. For high-temperature, high-pressure, and high-speed pumps, critical analysis should be performed to ensure an adequate safety margin between the first critical speed and the operating speed. Rotor components should be dynamically balanced, and the machining accuracy and assembly concentricity of rotating parts such as impellers, shaft sleeves, balance discs, or balance drums must be strictly controlled. For BB-type multistage pumps, attention should also be paid to inter-stage ring clearances, balance device clearances, and rotor axial positioning to avoid unstable axial forces and frictional vibration during operation. Third, the bearing housing bearing system must have good support rigidity. Bearing selection should meet radial load, axial load speed, and life requirements, and the lubrication method should be chosen based on power, speed, and temperature rise, such as oil bath, oil ring, forced lubrication, or oil mist lubrication. The bearing housing structure should avoid weak sections, ensuring sufficient rigidity and heat dissipation capacity. For high-temperature pumps, the effects of thermal expansion on bearing alignment and rotor centerline must be considered, and centerline support structures should be used when necessary to reduce vibration increases caused by thermal deformation. Fourth, the baseplate and nozzle loads significantly impact vibration. API pumps typically require a rigid baseplate structure, sufficient thickness and machining accuracy on the mounting surfaces for the motor, pump, and coupling. The base grouting surface, vent holes, grouting holes, and drainage structure should be designed properly to ensure dense on-site secondary grouting. The pump's suction and discharge piping should not transmit excessive external forces and moments to the pump casing, as this can cause casing deformation, misalignment, coupling misalignment, and ultimately vibration exceeding limits. Fifth, the manufacturing and assembly process must be strictly controlled. Shaft runout, impeller wear ring runout, shaft sleeve end face runout, bearing fits, mechanical seal compression, and coupling alignment accuracy all affect the final vibration values. After assembly, cold alignment should be performed, and hot alignment corrections should be considered when necessary During the factory performance test, vibration measurements should be taken at specified flow points, recording vibration velocity values in the horizontal, vertical, and axial directions. In summary, meeting the vibration requirements of API 610 / ISO 13709 is not simply a matter of promising "vibration compliance," but rather achieving it through proper selection, stable hydraulic design, high-rigidity rotors, reliable bearing support, robust baseplates, strict manufacturing and assembly, and standardized testing. Only by advancing vibration control to the design stage can long-term stable operation of the pump unit in the field be ensured. Jiangsu Haifa Machinery Manufacturing Co., Ltd. was restructured from Jiangsu Ligong Group Co., Ltd., founded in 1958, and the Jingjiang Stainless Steel Pump and Valve Factory of the Iron and Steel Research Institute of the Ministry of Metallurgical Industry. It mainly produces API 610 chemical process pumps - OH1, OH2, OH3, OH4 pumps, BB1, BB2, BB3, BB4, BB5 double-casing multistage pumps, VS1, VS4, VS5, VS6 barrel-type pumps, HES chemical process pumps, chemical pumps, petrochemical pumps, sixth-generation ultra-low carbon stainless steel high-quality leak-free molten urea pumps, urea hydrolyzer feed pumps, high-temperature asphalt, pitot tube pumps, rotary jet pumps, low-flow high-head pumps, multistage vortex pumps, high-temperature molten salt pumps, high-temperature nitric acid pumps, vertical sump pumps, magnetic drive pumps, low-temperature liquid hydrogen and methanol pumps, high-pressure liquid hydrogen pumps, high-temperature nitric acid magnetic drive pumps, magnetic drive pumps for solids-containing media, industrial pumps, canned motor pumps, slurry pumps, titanium tetrachloride pumps, self-priming pumps, PTFE-lined pumps, sandwich PTFE-lined pumps, leak-free pumps, desulfurization and denitrification pumps, alkali pumps, pumps, geothermal pumps, oil pumps, axial flow pumps, printing and dyeing pumps, dyeing and finishing pumps, Ti alloy pumps, C-276 material, Hastelloy, 316L material, 347 material, forced circulation pumps, fourth-generation nuclear pumps, nuclear island pumps, filter press-specific pumps, refrigerant pumps, long-shaft vertical sump pumps, CQC Class 1 energy efficiency chemical pumps, high-pressure descaler industrial pumps, and Chinese chemical pumps. www.jslgpump.com  Tel: 13905263417  E-mail: jslgpump@gmail.com  E-mail: jsareva@163.com