Tank, Vessel & Pressure Equipment Fabrication worked example

Pressure Test Water Volume at 98% fill and recovery efficiency: a worked example

Push fill and recovery efficiency up to 98% and the picture changes. This example computes every intermediate figure at that operating point. Use it when pressure test water volume in tank, vessel and pressure equipment fabrication needs a buy quantity for the next tank, vessel and pressure equipment fabrication run and you do not want to short the line.

The inputs for this scenario

  • Internal volume to fill for hydrostatic test: 500 gal (unchanged)
  • Water allowance per gallon of vessel volume: 0.08 ratio (unchanged)
  • Fill and recovery efficiency: 98 % (raised for this scenario; the documented default is 85)

Working through the calculation

  • Applying the documented formula (Required pressure test water volume = covered amount × use per unit ÷ transfer efficiency) to the inputs above produces each figure below.
  • At this operating point the engine returns 40.82 psi for required quantity, the number this scenario is built around.
  • At this operating point the engine returns 40 psi for theoretical amount.
  • At this operating point the engine returns 0.82 psi for loss allowance.
  • At this operating point the engine returns 98 % for efficiency.

How this compares with the baseline

  • Against the tool's baseline example, where fill and recovery efficiency sits at 85% and the headline result is 47.06 psi, this scenario comes in 13.27% below the baseline at 40.82 psi.
  • It computes the total water volume you must supply to hydrostatically fill and pressurize a vessel, grossed up for fill and recovery losses. The value of this scenario is the size of the gap it exposes: that gap, priced out over a year, is the budget you can justify spending to close it.

Results at a glance

  • Required quantity: 40.82 psi (headline result)
  • Theoretical amount: 40 psi
  • Loss allowance: 0.82 psi
  • Efficiency: 98 %

Run it with your numbers

  • Every input above is editable in the live Pressure Test Water Volume calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.