What is the specification of XH-7/XH-9 other than that of molecular sieve?
XH7 & XH9 indicate the type of molecular sieves made by UOP (US manufacturer) that use the brand name MOLSIV and the desiccants are designated by them as MOLSIV 4A- XH 7, MOLSIV 4A- XH9, MOLSIV 4A- XH5, MOLSIV 4A-XH6. The prefix 4A is used by most molecular sieve manufacturers and indicates that the size of the pores in the molecular sieve is 4 Angstrom or 0.4 nm (nano meters). The suffix XH 5 etc are the designations given by UOP to the molecular sieves developed by them. The higher the numbers following XH indicates a newer development and is also indicative of higher hydrated attrition strength (particularly XH7 & XH9) needed for 134a. Other specifications applicable to most desiccants also apply to molecular sieves; these being, Water capacity, Bead size (usually 1/16″ for mol sieves and 1/8″ for activated alumina and silica gel), crush strength, attrition strength both dry and hydrated.
