Abstract: A filling head (10) for a vacuum filling machine of the kind used for packaging powdered or granular products such as foodstuffs (e.g. powdered milk). The filling head has a downwardly extending delivery duct (15) which terminates in a delivery or outlet port (16) of annular shape defined between said duct and an adjustable valve member 17 mounted axially of said duct. The valve member is shaped as a conical frustum having the smaller end extending into said duct and adjustment is achieved by rotating said valve member on a threaded rod (18) extending axially within said duct. Thus the area of said delivery port may be varied to alter the compaction density of product in said duct and a supply hopper (21) to said duct. By reducing the port area the vacuum formed in a container being filled is increased as is the said density of product. The unique delivery port facilitates extremely high density packaging with a port of large area providing a rapid fill.