A pushing-dispensing and/or dosing element for dispensing of medium, in particular Composite Heavy Fluid Compound (CHFC), solves the technical problem of implantation of avoiding and/or limiting sliding and/or moving parts, exposed to the heavy medium, such as CHFC, thereof by using a flexible cartridge that behaves one way during the pushing of the CHFC, and another way during pumping of said CHFC out of the tank in which it is held.