Vertical Tank Strapping and Gauge Conversion

A vertical cylinder holds the same volume per inch all the way up, so the arithmetic is one constant and a multiplication -- and the value of having it in hand is CHECKING. A pumper who knows the tank's barrels per inch knows immediately what a two inch change is worth, and a ticket that disagrees is worth a second look. THE CERTIFIED STRAPPING TABLE IS THE LEGAL DOCUMENT AND THIS FORMULA IS NOT A SUBSTITUTE. Real tanks deviate from the ideal cylinder: shell courses of different thickness, bottom deadwood, an out-of-round shell, tilt. The strapping table captures all of that, which is exactly why it is measured rather than computed, and why custody transfer runs on it. TWO CORRECTIONS SIT BETWEEN GROSS AND NET AND BOTH ARE MONEY. Temperature correction to 60 degF, because crude expands appreciably and a warm afternoon gauge holds fewer standard barrels than the same height at dawn; and the deduction for sediment and water, which is volume that is not oil. On a run of a few hundred barrels the two together commonly move the ticket by more than ten barrels, which is why they are on it. The correction factor is ENTERED from the applicable petroleum measurement tables for the observed temperature and gravity rather than modelled here, because those tables are the authority and they differ by product. This computes an ideal-cylinder volume and applies entered corrections. It does not replace a certified strapping table, generate a correction factor from temperature and gravity, account for deadwood, tilt, out-of-roundness or floating-roof displacement, address bottom sediment, free water or a water cut measurement, handle horizontal or spherical vessels, or produce a custody transfer document. API MPMS, the certified strapping table, the purchaser's measurement procedures, and the operator govern.

barrels per foot = (pi/4) D^2 / 5.615 for an ideal vertical cylinder; gross = that times the gauge height; net = gross x the volume correction factor x (1 - the sediment and water fraction).

Ideal-cylinder geometry with an ENTERED volume correction factor and sediment-and-water deduction. The certified strapping table is the legal document for custody transfer and this is not a substitute for it.

One geometric constant and two multiplications.

Estimate. AHJ and licensed professional govern.

Field names used by the API: tank_diameter_ft, gauge_ft, gauge_in, closing_gauge_ft, closing_gauge_in, volume_correction_factor, sediment_water_pct, bbl_per_ft, bbl_per_in, gross_bbl, moved_bbl, net_bbl, correction_bbl, correction_pct

• Ideal cylinder deadwood, tilt, out-of-roundness and roof displacement are not modelledthe certified strapping table
• The correction factor is entered from the applicable petroleum measurement tables for the observed temperature and gravityAPI MPMS
• Not a custody transfer document a planning and checking numberthe purchaser's measurement procedures