Tweco Max 300 w-TD-750 - Manual (Page 22)

INSTALLATION PROCEDURES 16 Manual 0-2557
C. Filtering
An inline pneumatic dryer/evaporator type air filter,
capable of filtering to at least 5 microns, is required
when using air from a compressor. This type filter
will insure that moisture, oil, dirt, chips, rust particles,
and other contminants from the supply hose do not
enter the torch. For highly automated applications, a
refrigerated drier may be used.
NOTE
Do not use an air line filter with high pressure gas
cylinders.