Abstract: A compression apparatus for applying a compression force to a stack of filter disks comprising a compression activator and a compression applicator is provided. The compression activator includes a sleeve mounted on a first rod element, a first locking means for locking said sleeve in an upper position on the rod, a second locking means for locking said sleeve on a lower position on the first rod element and a lever for applying a force on said sleeve to move the sleeve along said first rod element. The compression applicator includes a compressible spring mounted on a second rod element, a third locking means for locking the spring in a compressed position when the third locking means is in a lower position on said second rod element.