LOCKING CAP FOR THREADED COVER FOR TANK AND DRUM OR LIKE FOR DEVELOPING SPECIALLY COLOR FILM

摘要

A tank includes a housing having an interior in which gas is likely to evolve and an opening communicating with the interior. The opening is closed by a removable cover which tends to become dislodged from the housing under the pressure of gas evolving in the interior. The cover compensates for the pressure exerted by gas, thus preventing dislodging of the same from the housing.