ANSI HI-9.6.2-2011 pdf download Rotodynamic Pumps for Assessment of Applied Nozzle Loads
9.6.2.1.3 Criteria for loading allowances
9.6.2.1.3.1 Driver/pump coupling alignment The radial movement of the pump shaft at the pump coupling hub due to nozzle loads shall not exceed 0.005 in. relative to initial alignment. Axial movement of the pump shaft at the pump coupling hub is not considered in this standard.
9.6.2.1.3.2 Internal pump distortion No contact between casing and impeller is allowed. The radial movement of the pump shaft with respect to the seal chamber due to nozzle loads shall not exceed 0.002 in. relative to initial position.
9.6.2.1.3.3 Pump hold-down bolts Fasteners used for hold-down bolts should have yield strength of 36,000 psi or greater, i.e., greater than or equal to the yield strength of SAE J429 Grade 1 fasteners. The maximum allowable tensile stress in the pump hold-down bolts is 90% of fastener’s material yield strength. The maximum allowable shear stress in the pump hold-down bolts is 25% of fastener’s material yield strength. The pump shall be bolted to the baseplate at both the casing feet and rear foot position(s) and sufficiently tightened to prevent slippage of the pump on the baseplate. Refer to API 686, Appendix E, for required torque values (use 0.5-in nominal bolt diameter torque value for Group 1 and 2 pumps, and 0.75-in nominal bolt diameter value for Group 3 pumps). It may be necessary to arrange for periodic tightening of the bolts to maintain required torque levels.
9.6.2.1.3.4 Pump mounting The base for which the loads in Tables 9.6.2.1 4b through
9.6.2.1.4e are established must be a fully grouted metal baseplate with anchor bolts. The base as a minimum must withstand the applied nozzle loads combined with normal operating loads (e.g., driver weight and pump weight). The base must be insalled and grouted in accordance with ANSIHI 1.4 Rotodynamic (Cntrifugal) Pumps for Manuals Describing Installation, Operation and Maintenance.
9.6.2.1.3.5 Nozzle stress The maximum stresses developed in the pump nozzles and flanges, constructed of a material listed in Table 9.6.2.1.7.2.2a, by the applied nozzle loads, combined with internal pressure, shall not exceed 26,250 psi tensile and 13,125 psi shear. By applying the temperature and material adjustment factors of Section 9.6.2.1.7.2.1, applied nozzle loads may be increased for stronger materials and must be decreased for weaker materials. The allowable suction nozzle stress was based on three-dimensional stress analysis methods. The allowable dis- charge nozzle stress was based on the method contained in the ASME Boiler and Pressure Vessel Code, 1983 edition, Section II, NC 3653, due to its complex geometry.