COOLING AND HEATING COILS IN THE FORM OF CLAMP-ON PANELS TO REGULATE OPERATING TEMPERATURES WITHIN VALVE BODIES AND USED AS VALVE WARMERS TO REDUCE AND MAINTAIN VISCOSITY AND INCREASE PUMPING EFFICIENCY AND TO REDUCE PRESSURE DROP, OR AS VALVE COOLERS TO ELIMINATE FLASHING WHEN HANDLING CRYOGENIC FLUIDS, VOLATILES, AEROSOLS OR SIMILAR PROCESS FLUIDS