Propane Information

Propane Vaporization Chart, Properties and Combustion Data

VAPORIZATION RATE - 100 lb. Propane Cylinder (Approx)

Pounds of propane in cylinderMaximum continuous draw in BTU/hr at various temperatures in degrees F.
20° 40° 60° 70°
100 113,000 167,000 214,000 277,000 300,000
90 104,000 152,000 200,000 247,000 277,000
80 94,000 137,000 180,000 214,000 236,000
70 83,000 122,000 160,000 199,000 214,000
60 75,000 109,000 140,000 176,000 192,000
50 64,000 94,000 125,000 154,000 167,000
40 55,000 79,000 105,000 131,000 141,000
30 45,000 66,000 85,000 107,000 118,000
20 36,000 51,000 68,000 83,000 92,000
10 28,000 38,000 49,000 60,000 66,000

This chart shows the vaporization rate of containers in terms of the temperature of the liquid and the wet surface area of the container. When the temperature is lower or if the container has less liquid in it, the vaporization rate of the container is a lower value.

propaneInfoList PROPANE DATA Properties of Propane:
Chemical Formula C3H8
BTU per Gallon (Vaporized) 91,690
BTU per Pound 21,591
Weight per Liquid Gallon 4.23
Vaporization Temperature –44°F
Specific Gravity - Vapor (Air=1) 1.53
 Specific Gravity - Liquid (Water=1) 0.51
Vaporization Rate (Liquid to Vapor) 272:1
Combustion Data :
Limits of Flammability, %of gas in air 2.3% to 9.5%
Air required to burn 1 Cu Ft Vapor 23.5 Cu Ft
Oxygen required to burn 1 Cu Ft Vapor 4.9 Cu Ft
Ignition Temperature 920-1029°F
 Optimum Flame Temperature 3500°F
Vapor Pressure at 0°F 28 PSI
Vapor Pressure at 70° F 122 PSI
Vapor Pressure at 100° F 190 PSI

Propane Vapor Pressure Chart, PSI

–30° –20° –10° 10° 20° 30° 40° 50° 60° 70° 80° 90° 100° 110°
100% Propane 6.8 11.5 17.5 24.5 34 42 53 65 78 93 110 128 150 177 204

Check List For Safe LP Gas Use:

  1. DO NOT use torches on or near combustible materials.
  2. Inspect equipment daily.
  3. Secure cylinders in a level, upright position. DO NOT invert or lay cylinders on their sides.
  4. Use only vapor equipment on cylinders equipped with vapor withdrawal valves. Use only liquid equipment on cylinders designed for liquid withdrawal. DO NOT invert vapor cylinders to dispense liquid.
  5. DO NOT apply flame to cylinders to increase pressure.
  6. DO NOT operate torches or any equipment if the odor of LP Gas (butane/propane) is evident. Immediately shut off all valves and, using soapy water, check all equipment for leaks.
  7. LP Gas (butane/propane) is heavier than air which causes it to accumulate in low areas. Check low areas for accumula- tion and ventilate. Be certain all work areas are well ventilated.
  8. Keep torches, open flame, and sources of ignition away from cylinders, regulators, and hose.
  9. Cylinder valves must be protected. DO NOT hoist cylinder by the valve.
  10. Gloves should be used at all times. Long sleeves, long pants, and boots are recommended.
  11. Never leave a lighted torch unattended.
  12. For more detailed information, consult your local LP dealer, Flame Engineering, NPGA, NRCA, or NFPA Pamphlet 58. This information is provided as a general guide for safe LP- Gas use and in no way constitutes a complete safety program.

Daily Equipment Check List

  1. Be sure you have a fire extinguisher (type ABC) on the job, easily accessible to each worker.
  2. Check LP cylinders for dents, damage to collar, damage to valve or corroded foot ring. Never hoist a cylinder by the valve. Secure cylinders in an upright position. Know whether you are using LIQUID or VAPOR WITHDRAWAL.
  3. Visually inspect all parts for damage and wear.
  4. Using soapy water, check all connections and fittings for leaks. DO NOT use a match or open flame.
  5. Ignite torch. Check operation of valve and other adjustable parts.


  • When extinguishing a torch, shut off cylinder valve and allow gas to burn out of lines.
  • Be certain to comply with all safety guidelines and local ordinances regarding the use of an open flame.
  • Please contact Flame Engineering, your local LP-Gas dealer or fire officials if you have questions regarding proper oper- ating procedures and safety guidelines.


  • Propane is heavier than air which causes it to accumulate in low areas. Be certain all areas are well ventilated.
  • Propane has a distinct odor. If you smell it, immediately discontinue work, extinguish all flames, find the leak and correct it.


Use extreme caution at all times. You are using an intense open flame. Disregard of safe practices can result in severe fire damage, serious personal injury or death.