Natural gas leak detection through pressure loss in pneumatic starter and prelube

An engine system comprising:

• an internal combustion engine;
• a fluid line including a first valve and a second valve upstream of the first valve;
• a pump fluidly coupled to the fluid line downstream of the first valve and operable by pressurized fluid in the fluid line;
• a pressure sensor;
• and
• a controller communicatively coupled to the first valve, the second valve, and the pressure sensor, the controller being structured to:
• measure a first pressure at a first position in the fluid line, the first position being between the first valve and the second valve, each of the first valve and the second valve being in a closed position;
• compare the first pressure to a first threshold;
• in response to the first pressure exceeding the first threshold, transmit a signal to depressurize the fluid line;
• after transmitting the signal to depressurize the fluid line, measure a second pressure in the fluid line and compare the second pressure to at least one of a second threshold and a third threshold, the second threshold being greater than the third threshold and less than the first threshold;
• and
• in response to the second pressure being less than the second threshold and exceeding the third threshold, transmit another signal to depressurize the fluid line.

A controller for an engine system, the controller comprising:

• an interface structured to communicate with a first valve, a second valve, and a pressure sensor of the engine system, the first valve positioned downstream of the second valve in a fluid line including a pump downstream of the first valve and operable by pressurized fluid in the fluid line, the controller structured to:
• measure a first pressure at a first position in the fluid line, the first position being between the first valve and the second valve, each of the first valve and the second valve being in a closed position;
• compare the first pressure to a first threshold;
• in response to the first pressure exceeding the first threshold, transmit a signal to depressurize the fluid line;
• after transmitting the signal to depressurize the fluid line, measure a second pressure in the fluid line and compare the second pressure to at least one of a second threshold and a third threshold, the second threshold being greater than the third threshold and less than the first threshold;
• and
• in response to the second pressure being less than the second threshold and exceeding the third threshold, transmit another signal to depressurize the fluid line.