Dear sir,

Maximum allowable vibration according to API for horizontal pumps is 3.0 mm / sec RMS ( for pumps having max. rpm = 3600 and max. power absorbed = 300KW), while for vertically suspended pumps this limit is 5.0 mm / sec RMS. Plesae note that 30% increase in these vibration limits are allowable for pumps running at flows outside the preffered operating region but within the allowable opearting region.