Fuel pump with inlet valve assembly

A fuel pump comprising:

• a fuel pump housing with a pumping chamber defined therein and an inlet valve bore extending along an inlet valve bore axis to an exterior of said fuel pump housing;
• a pumping plunger which reciprocates within a plunger bore such that an intake stroke of said pumping plunger increases volume of said pumping chamber and a compression stroke of said pumping plunger decreases volume of said pumping chamber;
• and
• an inlet valve assembly which 1) selectively provides fluid communication between an inlet of said fuel pump and said pumping chamber and 2) selectively prevents fluid communication between said inlet of said fuel pump and said pumping chamber, said inlet valve assembly comprising:
• an inner housing which is received within said inlet valve bore such that said inner housing extends to the exterior of said fuel pump housing and such that an outer periphery of said inner housing is sealed to an inner periphery of said inlet valve bore such that fuel is prevented from passing radially between said inner housing and said inlet valve bore to the exterior of said fuel pump housing;
• an outer housing which is located outside of said fuel pump housing and circumferentially surrounds said inner housing, wherein an annular chamber is defined radially between said inner housing and said outer housing and axially between said outer housing and said fuel pump housing;
• and
• a sealing ring which is made of an elastomer material and which is annular in shape and located within said annular chamber such that said sealing ring is compressed axially against said fuel pump housing and said outer housing.