hydropneumatic testing

[cherrybird]

Пожалуйста, помогите перевести:
hydropneumatic testing.
Слово встречается в следующем контексте:
hydropneumatic or leaking testing may му accepted under the conditions specidied in (2.3) and (2.4). respectively, provided that at least one tank of each type is structurally tested, to be selected in connection with the approval of the design/