the present invention relates to fuel cell modules . the fuel cell module includes a housing that contains a plurality of fuel cell elements called unicells . each unicell comprises a plurality of microcells . the housing is divided into a plurality of housing sections . a compressible bulkhead disposed between two adjacent housing sections and has a plurality of holes formed therein to allow respective unicells to pass through the bulkhead . a clamp element compresses the bulkhead to form a gas - tight seal between said bulkhead and the unicells .