Fluid flow device

A device for controlling the flow of fluid through a conduit from an upstream side of the device to a downstream side of the device, the device comprising:

• a casing;
• a valve seat mounted on the casing, the valve seat defining a valve aperture;
• a mounting member arranged on the downstream side of the valve aperture;
• a valve member movably mounted on the mounting member, wherein the valve member is arranged to move reciprocally to selectively open and close the valve aperture, thereby controlling the flow of the fluid through the valve aperture;
• a seal retaining member, arranged adjacent the valve seat such that the seal retaining member and the valve seat together define a seal retaining groove;
• and
• a compliant seal arranged within the seal retaining groove for substantially sealing the valve aperture when the valve member is moved to close the valve aperture;
• wherein the valve seat and the casing together define a slot for receiving the seal retaining member, and wherein the seal retaining member is smaller than the slot within which the seal retaining member is arranged, thereby defining a leak path between the seal retaining member and the casing, and between the seal retaining member and the valve seat.