Cryogenic Storage & LNG Equipment worked example

Tank Boil-Off Rate at 99% target maximum boil-off rate: a worked example

What does the result look like when target maximum boil-off rate reaches 99%? The full calculation is worked below with real intermediate numbers. Use it when tank boil-off rate in cryogenic storage and lng equipment needs a clean rate and gap-to-target you can put on a tier board.

The inputs for this scenario

  • Boil-off or vented liquid equivalent: 8 gal (unchanged)
  • Starting usable liquid inventory: 250 gal (unchanged)
  • Target maximum boil-off rate: 99 % per period (raised for this scenario; the documented default is 95)

Working through the calculation

  • Applying the documented formula (Tank boil-off rate = boil-off or vented liquid equivalent ÷ starting usable liquid inventory × 100) to the inputs above produces each figure below.
  • At this operating point the engine returns 3.2 % per period for measured tank boil-off rate, the number this scenario is built around.
  • At this operating point the engine returns 95.8 points for boil-off above target.
  • At this operating point the engine returns 8 count for boil-off liquid equivalent.
  • At this operating point the engine returns 250 count for starting usable liquid inventory.

How this compares with the baseline

  • Against the tool's baseline example, where target maximum boil-off rate sits at 95% and the headline result is 3.2 % per period, this scenario lands almost exactly on the baseline at 3.2 % per period.
  • A figure at this level is achievable when target maximum boil-off rate is genuinely sustained, not just peaked for a shift. Rate alone doesn't isolate the cause — high ambient heat, frequent valve cycling, low fill level, and lost vacuum all raise boil-off, so a high reading needs follow-up to diagnose.

Results at a glance

  • Measured tank boil-off rate: 3.2 % per period (headline result)
  • Boil-off above target: 95.8 points
  • Boil-off liquid equivalent: 8 count
  • Starting usable liquid inventory: 250 count

Run it with your numbers

  • Every input above is editable in the live Tank Boil-Off Rate calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.