What is the difference between Air Leak Test and Pneumatic tests?

  AIR LEAK TEST USES COMPRESSED AIR TO  CHECK  FOR LEAKS, USUALLY  WITH SOAP WATER ON  THE JOINTS (IF  BUBBLES  ARE  THERE THEN  THERE IS LEAK)

IF  THE FLUID USED  TO PRESSURISE A SYSTEM IS GAS USUALLY AIR  OR INTERT GAS IT IS  CALLED PNEUMATIC TEST. A PNEUMATIC TEST ISS HIGHLY DANGEROUS THAN  HYDROTEST DUE TO  HIGHER  ENERGY  CONTENT OF  COMPRESSED GAS  AND  THIS  TYPE  OF  TEST  IS LIMITED TO LOWER PRESSURES SMALLER SYSTEMS.