** Chemical makers Navin Fluorine NAFL.NS down 1.7%, SRF SRFL.NS and PI Industries PIIL.NS decline 2.4% each
** U.S. imposes higher tariffs on Indian goods
** NAFL, SRFL export refrigerant gases, fluorochemicals to U.S.
** PIIL could be indirectly impacted through its broader chemicals exposure
** Cos face potential margin pressure, order slowdowns
** Analysts rate PIIL and NAFL "buy", SRFL rated "hold" - data compiled by LSEG
** Since July 31 when Trump announced initial 25% tariff, PII falls 6.5%, SRFL declines nearly 5% and NAFL drops 1.7%