Abstract: The present disclosure is directed at a compression device for compressing a stack to prevent leaks and at an apparatus including the stack and the compression device. The stack includes a pair of rigid end plates located at opposing ends of the stack, a plurality of membrane bounded compartments layered between one of the rigid end plates and the other of the rigid end plates and fluid manifolds extending through the membrane bound compartments. The compression device is fixedly coupled to opposing ends of the pair of rigid end plates and includes compression members movable to compress one of the rigid end plates towards the other of the rigid end plates. The compression members are positioned to apply force to the stack in the vicinity of the fluid manifolds.