1.5 to 1.7mm molecular sieve 10 years professional manufacturer for 3A, 4A,5A, 13X drying,absorbent,cleaning ect. 1.5 to ... apparatus -is used in this case.Methods for regeneration of molecular sieves include pressure change (as in oxygen concentrators), heating and purging ... (as when used in dehydration), or heating under high vacuum.3A (pore size 3 Å): Adsorbs NH3, H2O, (not C2H6), good for ...