A valve (16) reciprocates with a constant stroke in the former tube (2) of a form-fill apparatus to dispense doses of filling material from the tube by ejecting the material through an outlet nozzle (8). The size of the doses is adjustable, in one form of the invention, by feeding the material is fed through an adjustable dosing opening immediately adjacent the valve. In another form of the invention, the valve (16) is adjustably positionable relative to the former tube (2) to vary the mean position of reciprocation of the valve relative to the tube. In a further form of the invention, an adjustably controllable head of material is maintained in the former tube to determine the rate at which it is fed to the valve (16).
