Med Gas Calculators — EMGS Internal Tools

O₂

Oxygen

Compressed

244 cu ft

6,909 L | 2200 psig full

Cylinder color: Green (US)

AIR

Medical Air

Compressed

231 cu ft

6,541 L | 2200 psig full

Cylinder color: Yellow (US)

N₂

Nitrogen

Compressed

226 cu ft

6,400 L | 2200 psig full

Cylinder color: Black (US)

Helium

Compressed

212 cu ft

6,003 L | 2265 psig full

Cylinder color: Brown (US)

N₂O

Nitrous Oxide

Liquefied

558 cu ft

15,801 L | 745 psig @ 70°F

⚠ Weigh to determine level

CO₂

Carbon Dioxide

Liquefied

559 cu ft

15,829 L | 838 psig @ 70°F

⚠ Weigh to determine level

Liquid Oxygen Dewars

LOX 180L

Liquid Oxygen — 180 L Dewar

Liquid / Dewar

5,471 cu ft

154,908 L gas | 180 L liquid full

860.6 L gas per L liquid | 30.4 cu ft/L

LOX 230L

Liquid Oxygen — 230 L Dewar

Liquid / Dewar

6,990 cu ft

197,938 L gas | 230 L liquid full

860.6 L gas per L liquid | 30.4 cu ft/L

Remaining Content Calculator

For compressed gases, enter the current gauge pressure. For liquefied cylinders (N₂O, CO₂), enter the cylinder weight. For LOX dewars, enter the liquid liters remaining.

Gas / Container Type

Current Gauge Pressure (psig)

Number of Cylinders

H Cylinder Full Reference

Gas	State	Full Pressure	Cu Ft	Liters	Lbs (net)
O₂ Oxygen	Compressed	2200 psig	244	6,909	—
AIR Medical Air	Compressed	2200 psig	231	6,541	—
N₂ Nitrogen	Compressed	2200 psig	226	6,400	—
He Helium	Compressed	2265 psig	212	6,003	—
N₂O Nitrous Oxide	Liquefied	745 psig*	558	15,801	63.8
CO₂ Carbon Dioxide	Liquefied	838 psig*	559	15,829	63.9
LOX Liq. Oxygen 180L Dewar	Liquid/Dewar	—	5,471	154,908	180 L liq.
LOX Liq. Oxygen 230L Dewar	Liquid/Dewar	—	6,990	197,938	230 L liq.

* Liquefied gas pressure is vapor pressure at 70°F — stays near constant until liquid is depleted. H cylinder contents at standard conditions: 70°F (21.1°C), 14.696 psia. LOX dewar gaseous equivalent calculated at 860.6 L gas per L liquid.
Source: NFPA 99 Health Care Facilities Code, 2024 Edition, Table A.11.3.5 (H cylinders)

Expansion Factors (Liquefied Gases)

Gas	Cu Ft per lb liquid	Liters gas per L liquid	Cu Ft per L liquid
O₂ (Liquid Oxygen / LOX)	12.08	860.6	30.4
N₂O (Nitrous Oxide)	8.741	545.6	19.3
CO₂ (Carbon Dioxide)	8.741	545.6	19.3

Gas Type

Cylinders Online

Current Gauge Pressure (psig)

Full = 2200 psig

System Flow Rate

Airflow Unit Converter

Enter a value in any field — all other units update instantly.

CFM — Cubic Feet per Minute

LPM — Liters per Minute

SCFM — Standard Cubic Feet per Minute

SLPM — Standard Liters per Minute

Standard ref: 68°F (20°C), 14.696 psia, 0% RH

ACFM ↔ SCFM Converter

Corrects actual flow for real pressure, temperature, and humidity conditions.

Actual Flow (ACFM)

Direction

Actual Pressure (psia)

Actual Temperature

Relative Humidity (%)

Standard Condition Preset

Airflow Conversion Quick Reference

From	To	Multiply By	Formula
CFM	LPM	28.3168	LPM = CFM × 28.3168
LPM	CFM	0.035315	CFM = LPM × 0.035315
SCFM	SLPM	28.3168	SLPM = SCFM × 28.3168
SLPM	SCFM	0.035315	SCFM = SLPM × 0.035315
ACFM	SCFM	variable	SCFM = ACFM × (P_act/P_std) × (T_std/T_act)
SCFM	ACFM	variable	ACFM = SCFM × (P_std/P_act) × (T_act/T_std)

Temperatures in formulas must be in absolute Rankine (°R = °F + 459.67). SCFM/SLPM are "standard" and are equivalent via the same 28.3168 factor. ACFM corrections account for actual site conditions (altitude, temperature, humidity) vs. the defined standard reference point.

DUTY CYCLE CALCULATOR

Units Installed

Units Active (Lead/Lag Running)

Peak System Demand (SCFM)

Receiver Tank Volume (gallons)

RUN HOURS LOG ANALYSIS

Upload a spreadsheet or enter data manually to analyze duty cycles over time. Supports cumulative run-hour logs (Run Hours Unit 1, Unit 2…) and period-based logs (Date, Unit, Run Hours).

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Upload an .xlsx or .csv file. The tool auto-detects cumulative run-hour columns (Run Hours Unit 1, 2…) or period-based columns.

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