Patent ID: 8794939

Claim:
A pump head for a fuel pump for use in a common rail fuel injection system, the pump head comprising: a pump head housing; a pumping chamber defined within the pump head housing; and an inlet valve arrangement for controlling fuel flow into the pumping chamber, the inlet valve arrangement including a valve member moveable in a bore defined in the housing, said bore configured to guide the valve member at an elongate neck of the valve member, said valve member moveable between open and closed positions in response to fuel pressure within a gallery, wherein the gallery communicates with an external chamber defined by a closure member in the form of a hollow cap mounted externally to the pump head housing, such that, in use, the gallery communicates with the external chamber via a first passage defined in the housing and a source of low-pressure fuel communicates with the external chamber via a second passage defined in the housing, wherein all of the fuel flowing between the first passage and the second passage must flow through the interior of the hollow cap, wherein the pump head housing defines a projection which locates the closure member on the projection.