Inspecting the Plumbing Components

sd mm 47.04.003

See Fig. for plumbing component locations.

  1. Pressure Control Regulator

  2. Vapor Shutoff Valve

  3. Fuel Fill Hose

  4. Secondary Relief Valve (red cap)

  5. Fuel Fill Fitting

  6. Fuel Level Sender Box

  7. Primary Relief Valve

  8. Tank Pressure Gauge

  9. Fill Vent Fitting

  10. Excess Flow Valve

  11. Fuel Shutoff Valve (liquid)

  12. Fill Check Valve

Fig. 1, Fuel Tank Plumbing Components

Use a bubble solution to check for leaks while performing the following visual inspection.

  1. Check the following components for signs of damage or leaks:

    • pressure control regulator

    • vapor shutoff valve

    • secondary relief valve

    • primary relief valve and threaded connections

    • excess flow valve

    • fuel shutoff valve

    • fill check valve

  2. Inspect the fuel fill line for signs of damage, kinked or crushed piping, or chafing.
  3. Ensure the red cap is present on the secondary relief valve.
  4. Inspect the fuel tank pressure gauge for cracks in the sight glass. Ensure the indicator needle is present and in working condition. Inspect the gauge face for accuracy and legibility.
  5. Inspect all vent lines for kinks, and signs of leaks or damage.
  6. Replace leaking or damaged fuel lines. Repair or replace leaking or damaged fittings.
Note:
Parent topic: LNG Fuel System Inspection
Document Number: 0000120398
Manual Publication Date: 2024-05-23
Topic Publication Date: 2025-07-31