Fuel piping structure

A fuel piping structure comprising:

• a fuel pipe through the inside of which fuel flows;
• a pressure sensor that detects a pressure of the fuel inside the fuel pipe;
• a sensor main body formed in a column shape, the sensor main body comprising an outer-peripheral projecting part formed on the column shape, the outer-peripheral projecting part projecting to an outer-peripheral side of the column shape, the sensor main body being connected to the fuel pipe by using the projecting part, the sensor main body holding the pressure sensor disposed therein, the sensor main body comprising a communication channel formed therein, the pressure sensor being in communication with the fuel pipe through the communication channel;
• and
• a sensor main body holder with a through hole formed therein, the sensor main body holder being connected with a flange part of the fuel pipe, the sensor main body holder being configured to hold the sensor main body by having an inner side of the through hole press an outer side of the outer-peripheral projecting part of the sensor main body toward the fuel pipe,
• wherein
• a ring-shaped elastic washer is provided between an underside of the outer-peripheral projecting part of the sensor main body and the flange part of the fuel pipe, the underside of the outer-peripheral projecting part of the sensor main body being pressed against the flange part,
• a tip side of the sensor main body is inserted into a recessed part and the communication channel is in communication with the recessed part, the recessed part being formed in the fuel pipe and in communication with the inside of the fuel pipe,
• a ring-shaped seal member is provided on the tip side of the sensor main body, and
• a conduction channel is formed and includes a first portion between an inner-peripheral surface of the through hole of the sensor main body holder and an outer-peripheral surface of the outer-peripheral projecting part of the sensor main body, a second portion including a gap formed by the ring-shaped elastic washer, and a third portion including a gap between an outer-peripheral surface on the tip side of the sensor main body and an inner-peripheral surface of the recessed part of the fuel pipe, the conduction channel being configured to supply a seal test fluid to the seal member, and
• wherein a masking jig covers an outer side of the sensor main body and main body holder to permit application of the seal test fluid into the conduction channel such that the seal test fluid reaches the seal member.