(57) A fluid flow control device (10) which is employed in conjunction with a fluid pump
(12) and which functions to restrict reverse flow of liquid which is induced by the
fluid pump to flow in a forward direction through the device from a source (11) of
the liquid. The device comprises a housing (20 or 50) which contains first and second
chambers (21 and 22 or 51 and 52), and a tube (26 and 37 or 54 and 60) is located
in each of the chambers. Thetubes (26,37, 54 and 60) define fluid passageways (27,
36, 55 and 61) through which the liquid is induced to flow in passing into the respective
chambers (21, 22, 51 and 52), and the tubes extend upwardly through the respective
chambers to a level above the level of liquid which is contained in the chambers.
Valve members (30,39, 59 and 63) are located at the upper end of the respective tubes
(26,37, 54 and 60), the valve members providing for forward flow of liquid into the
chambers from the respective tubes and serving to prevent the liquid from leaking
in a reverse direction along the fluid passageways (27,36,55 and 61 A control port
(32 or 64) enters the housing (20 or 50) and is connectable to the fluid pump (12)
for the purpose of applying alternating negative and positive pressurisation to the
chambers whereby the liquid is induced to flow into and through the chambers.
|
|
