Abstract: A dispenser pump has a fixed spout (15) on an upper component (10) which is rotatable relative to a lower component (11) adapted to be fitted to a container (not shown). For transport and storage the spout (15) is rotated so that its inner opening is obturated by the distal end of an arm (13) of the lower component which circumferentially divides its discharge compartment (31). Simultaneously an air opening (22) of the upper component is obturated by the arm (13) which also circumferentially divides an annular air chamber (32) below the discharge compartment (31). The compartment (31) and air chamber (32) are separated by an annular barrier seal (23) in rubbing contact with the internal wall of the upper component (10). By this provision the danger of leakage is so much reduced that it is not necessary to provide a mechanical lock for the pump when the dispenser is closed.